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-rw-r--r--com32/lib/libpng/ANNOUNCE112
-rw-r--r--com32/lib/libpng/CHANGES5744
-rw-r--r--com32/lib/libpng/LICENSE199
-rw-r--r--com32/lib/libpng/README254
-rw-r--r--com32/lib/libpng/TODO44
-rw-r--r--com32/lib/libpng/example.c650
-rw-r--r--com32/lib/libpng/libpng.34636
-rw-r--r--com32/lib/libpng/libpngpf.3816
-rw-r--r--com32/lib/libpng/png.574
-rw-r--r--com32/lib/libpng/png.c4650
-rw-r--r--com32/lib/libpng/pngerror.c929
-rw-r--r--com32/lib/libpng/pngget.c1003
-rw-r--r--com32/lib/libpng/pngmem.c675
-rw-r--r--com32/lib/libpng/pngpread.c1430
-rw-r--r--com32/lib/libpng/pngread.c4571
-rw-r--r--com32/lib/libpng/pngrio.c116
-rw-r--r--com32/lib/libpng/pngrtran.c5537
-rw-r--r--com32/lib/libpng/pngrutil.c4949
-rw-r--r--com32/lib/libpng/pngset.c1804
-rw-r--r--com32/lib/libpng/pngtest.c1853
-rw-r--r--com32/lib/libpng/pngtrans.c641
-rw-r--r--com32/lib/libpng/pngwio.c170
-rw-r--r--com32/lib/libpng/pngwrite.c2643
-rw-r--r--com32/lib/libpng/pngwtran.c359
-rw-r--r--com32/lib/libpng/pngwutil.c3241
-rw-r--r--com32/lib/sys/vesa/background.c21
26 files changed, 30588 insertions, 16533 deletions
diff --git a/com32/lib/libpng/ANNOUNCE b/com32/lib/libpng/ANNOUNCE
index b0824ee7..f1724c0d 100644
--- a/com32/lib/libpng/ANNOUNCE
+++ b/com32/lib/libpng/ANNOUNCE
@@ -1,57 +1,77 @@
+libpng 1.6.36 - December 1, 2018
+================================
-Libpng 1.2.44 - June 26, 2010
+This is a public release of libpng, intended for use in production code.
-This is a public release of libpng, intended for use in production codes.
-Files available for download:
+Files available for download
+----------------------------
-Source files with LF line endings (for Unix/Linux) and with a
-"configure" script
+Source files with LF line endings (for Unix/Linux):
- libpng-1.2.44.tar.xz (LZMA-compressed, recommended)
- libpng-1.2.44.tar.gz
- libpng-1.2.44.tar.bz2
+ * libpng-1.6.36.tar.xz (LZMA-compressed, recommended)
+ * libpng-1.6.36.tar.gz
-Source files with LF line endings (for Unix/Linux) without the
-"configure" script
+Source files with CRLF line endings (for Windows):
- libpng-1.2.44-no-config.tar.xz (LZMA-compressed, recommended)
- libpng-1.2.44-no-config.tar.gz
- libpng-1.2.44-no-config.tar.bz2
-
-Source files with CRLF line endings (for Windows), without the
-"configure" script
-
- lpng1244.zip
- lpng1244.7z
- lpng1244.tar.bz2
-
-Project files
-
- libpng-1.2.44-project-netware.zip
- libpng-1.2.44-project-wince.zip
+ * lp1636.7z (LZMA-compressed, recommended)
+ * lp1636.zip
Other information:
- libpng-1.2.44-README.txt
- libpng-1.2.44-KNOWNBUGS.txt
- libpng-1.2.44-LICENSE.txt
- libpng-1.2.44-Y2K-compliance.txt
- libpng-1.2.44-[previous version]-diff.txt
-
-Changes since the last public release (1.2.43):
-
-version 1.2.44 [June 26, 2010]
-
- Rewrote png_process_IDAT_data to consistently treat extra data as warnings
- and handle end conditions more cleanly.
- Removed the now-redundant check for out-of-bounds new_row from example.c
-
-
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-
-(subscription required; visit
+ * README.md
+ * LICENSE.md
+ * AUTHORS.md
+ * TRADEMARK.md
+
+
+IMPORTANT licensing update: libpng license v2
+---------------------------------------------
+
+The new libpng license comprises the terms and conditions from the zlib
+license, and the disclaimer from the Boost license.
+
+The legacy libpng license, used until libpng-1.6.35, is appended to the
+new license, following the precedent established in the Python Software
+Foundation License version 2.
+
+From now on, the list of contributing authors shall be maintained in a
+separate AUTHORS file. The lists of previous contributing authors,
+mentioned in the legacy libpng license and considered to be an integral
+part of that license, are kept intact, with no further updates.
+
+
+Changes since the previous public release (version 1.6.35)
+----------------------------------------------------------
+
+ * Optimized png_do_expand_palette for ARM processors.
+ Improved performance by around 10-22% on a recent ARM Chromebook.
+ (Contributed by Richard Townsend, ARM Holdings)
+ * Fixed manipulation of machine-specific optimization options.
+ (Contributed by Vicki Pfau)
+ * Used memcpy instead of manual pointer arithmetic on Intel SSE2.
+ (Contributed by Samuel Williams)
+ * Fixed build errors with MSVC on ARM64.
+ (Contributed by Zhijie Liang)
+ * Fixed detection of libm in CMakeLists.
+ (Contributed by Cameron Cawley)
+ * Fixed incorrect creation of pkg-config file in CMakeLists.
+ (Contributed by Kyle Bentley)
+ * Fixed the CMake build on Windows MSYS by avoiding symlinks.
+ * Fixed a build warning on OpenBSD.
+ (Contributed by Theo Buehler)
+ * Fixed various typos in comments.
+ (Contributed by "luz.paz")
+ * Raised the minimum required CMake version from 3.0.2 to 3.1.
+ * Removed yet more of the vestigial support for pre-ANSI C compilers.
+ * Removed ancient makefiles for ancient systems that have been broken
+ across all previous libpng-1.6.x versions.
+ * Removed the Y2K compliance statement and the export control
+ information.
+ * Applied various code style and documentation fixes.
+
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net.
+Subscription is required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
-
-Glenn R-P
+to subscribe.
diff --git a/com32/lib/libpng/CHANGES b/com32/lib/libpng/CHANGES
index 90a3e2be..bdd44806 100644
--- a/com32/lib/libpng/CHANGES
+++ b/com32/lib/libpng/CHANGES
@@ -1,11 +1,13 @@
-/*
CHANGES - changes for libpng
-version 0.2
+version 0.1 [March 29, 1995]
+ initial work-in-progress release
+
+version 0.2 [April 1, 1995]
added reader into png.h
fixed small problems in stub file
-version 0.3
+version 0.3 [April 8, 1995]
added pull reader
split up pngwrite.c to several files
added pnglib.txt
@@ -16,7 +18,7 @@ version 0.3
added K&R support
added check for 64 KB blocks for 16 bit machines
-version 0.4
+version 0.4 [April 26, 1995]
cleaned up code and commented code
simplified time handling into png_time
created png_color_16 and png_color_8 to handle color needs
@@ -27,28 +29,29 @@ version 0.4
cleaned up zTXt reader and writer (using zlib's Reset functions)
split transformations into pngrtran.c and pngwtran.c
-version 0.5
+version 0.5 [April 30, 1995]
interfaced with zlib 0.8
fixed many reading and writing bugs
saved using 3 spaces instead of tabs
-version 0.6
+version 0.6 [May 1, 1995]
+ first beta release
added png_large_malloc() and png_large_free()
added png_size_t
cleaned up some compiler warnings
added png_start_read_image()
-version 0.7
+version 0.7 [June 24, 1995]
cleaned up lots of bugs
finished dithering and other stuff
added test program
changed name from pnglib to libpng
-version 0.71 [June, 1995]
+version 0.71 [June 26, 1995]
changed pngtest.png for zlib 0.93
fixed error in libpng.txt and example.c
-version 0.8
+version 0.8 [August 20, 1995]
cleaned up some bugs
added png_set_filler()
split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
@@ -62,191 +65,199 @@ version 0.8
changed external functions passing floats to doubles (k&r problems?)
put all the configurable stuff in pngconf.h
enabled png_set_shift to work with paletted images on read
- added png_read_update_info() - updates info structure with
- transformations
+ added png_read_update_info() - updates info structure with transformations
-version 0.81 [August, 1995]
+Version 0.81 [August, 1995]
incorporated Tim Wegner's medium model code (thanks, Tim)
-version 0.82 [September, 1995]
+Version 0.82 [September, 1995]
[unspecified changes]
-version 0.85 [December, 1995]
+Version 0.85 [December, 1995]
added more medium model code (almost everything's a far)
added i/o, error, and memory callback functions
- fixed some bugs (16 bit, 4 bit interlaced, etc.)
+ fixed some bugs (16-bit, 4-bit interlaced, etc.)
added first run progressive reader (barely tested)
-version 0.86 [January, 1996]
+Version 0.86 [January, 1996]
fixed bugs
improved documentation
-version 0.87 [January, 1996]
+Version 0.87 [January, 1996]
fixed medium model bugs
fixed other bugs introduced in 0.85 and 0.86
added some minor documentation
-version 0.88 [January, 1996]
+Version 0.88 [January, 1996]
fixed progressive bugs
replaced tabs with spaces
cleaned up documentation
added callbacks for read/write and warning/error functions
-version 0.89 [July, 1996]
- added new initialization API to make libpng work better with shared libs
- we now have png_create_read_struct(), png_create_write_struct(),
- png_create_info_struct(), png_destroy_read_struct(), and
- png_destroy_write_struct() instead of the separate calls to
- malloc and png_read_init(), png_info_init(), and png_write_init()
- changed warning/error callback functions to fix bug - this means you
- should use the new initialization API if you were using the old
- png_set_message_fn() calls, and that the old API no longer exists
- so that people are aware that they need to change their code
- changed filter selection API to allow selection of multiple filters
- since it didn't work in previous versions of libpng anyways
- optimized filter selection code
- fixed png_set_background() to allow using an arbitrary RGB color for
- paletted images
- fixed gamma and background correction for paletted images, so
- png_correct_palette is not needed unless you are correcting an
- external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
- in pngconf.h) - if nobody uses this, it may disappear in the future.
- fixed bug with Borland 64K memory allocation (Alexander Lehmann)
- fixed bug in interlace handling (Smarasderagd, I think)
- added more error checking for writing and image to reduce invalid files
- separated read and write functions so that they won't both be linked
- into a binary when only reading or writing functionality is used
- new pngtest image also has interlacing and zTXt
- updated documentation to reflect new API
-
-version 0.90 [January, 1997]
- made CRC errors/warnings on critical and ancillary chunks configurable
+Version 0.89 [June 5, 1996]
+ Added new initialization API to make libpng work better with shared libs
+ we now have png_create_read_struct(), png_create_write_struct(),
+ png_create_info_struct(), png_destroy_read_struct(), and
+ png_destroy_write_struct() instead of the separate calls to
+ malloc and png_read_init(), png_info_init(), and png_write_init()
+ Changed warning/error callback functions to fix bug - this means you
+ should use the new initialization API if you were using the old
+ png_set_message_fn() calls, and that the old API no longer exists
+ so that people are aware that they need to change their code
+ Changed filter selection API to allow selection of multiple filters
+ since it didn't work in previous versions of libpng anyways
+ Optimized filter selection code
+ Fixed png_set_background() to allow using an arbitrary RGB color for
+ paletted images
+ Fixed gamma and background correction for paletted images, so
+ png_correct_palette is not needed unless you are correcting an
+ external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
+ in pngconf.h) - if nobody uses this, it may disappear in the future.
+ Fixed bug with Borland 64K memory allocation (Alexander Lehmann)
+ Fixed bug in interlace handling (Smarasderagd, I think)
+ Added more error checking for writing and image to reduce invalid files
+ Separated read and write functions so that they won't both be linked
+ into a binary when only reading or writing functionality is used
+ New pngtest image also has interlacing and zTXt
+ Updated documentation to reflect new API
+
+Version 0.89c [June 17, 1996]
+ Bug fixes.
+
+Version 0.90 [January, 1997]
+ Made CRC errors/warnings on critical and ancillary chunks configurable
libpng will use the zlib CRC routines by (compile-time) default
- changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
- added external C++ wrapper statements to png.h (Gilles Dauphin)
- allow PNG file to be read when some or all of file signature has already
- been read from the beginning of the stream. ****This affects the size
- of info_struct and invalidates all programs that use a shared libpng****
- fixed png_filler() declarations
- fixed? background color conversions
- fixed order of error function pointers to match documentation
- current chunk name is now available in png_struct to reduce the number
- of nearly identical error messages (will simplify multi-lingual
- support when available)
- try to get ready for unknown-chunk callback functions:
- - previously read critical chunks are flagged, so the chunk handling
- routines can determine if the chunk is in the right place
- - all chunk handling routines have the same prototypes, so we will
- be able to handle all chunks via a callback mechanism
- try to fix Linux "setjmp" buffer size problems
- removed png_large_malloc, png_large_free, and png_realloc functions.
-
-version 0.95 [March, 1997]
- fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
- fixed bug in PNG file signature compares when start != 0
- changed parameter type of png_set_filler(...filler...) from png_byte
- to png_uint_32
- added test for MACOS to ensure that both math.h and fp.h are not #included
- added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
- added "packswap" transformation, which changes the endianness of
- packed-pixel bytes (Kevin Bracey)
- added "strip_alpha" transformation, which removes the alpha channel of
- input images without using it (not necessarily a good idea)
- added "swap_alpha" transformation, which puts the alpha channel in front
- of the color bytes instead of after
- removed all implicit variable tests which assume NULL == 0 (I think)
- changed several variables to "png_size_t" to show 16/32-bit limitations
- added new pCAL chunk read/write support
- added experimental filter selection weighting (Greg Roelofs)
- removed old png_set_rgbx() and png_set_xrgb() functions that have been
- obsolete for about 2 years now (use png_set_filler() instead)
- added macros to read 16- and 32-bit ints directly from buffer, to be
- used only on those systems that support it (namely PowerPC and 680x0)
- With some testing, this may become the default for MACOS/PPC systems.
- only calculate CRC on data if we are going to use it
- added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
- added macros for simple libpng debugging output selectable at compile time
- removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
- more description of info_struct in libpng.txt and png.h
- more instructions in example.c
- more chunk types tested in pngtest.c
- renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
- png_set_<chunk>. We now have corresponding png_get_<chunk>
- functions in pngget.c to get information in info_ptr. This isolates
- the application from the internal organization of png_info_struct
- (good for shared library implementations).
-
-version 0.96 [May, 1997]
- fixed serious bug with < 8bpp images introduced in 0.95
- fixed 256-color transparency bug (Greg Roelofs)
- fixed up documentation (Greg Roelofs, Laszlo Nyul)
- fixed "error" in pngconf.h for Linux setjmp() behaviour
- fixed DOS medium model support (Tim Wegner)
- fixed png_check_keyword() for case with error in static string text
- added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
- added typecasts to quiet compiler errors
- added more debugging info
-
-version 0.97 [January, 1998]
- removed PNG_USE_OWN_CRC capability
- relocated png_set_crc_action from pngrutil.c to pngrtran.c
- fixed typecasts of "new_key", etc. (Andreas Dilger)
- added RFC 1152 [sic] date support
- fixed bug in gamma handling of 4-bit grayscale
- added 2-bit grayscale gamma handling (Glenn R-P)
- added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
- minor corrections in libpng.txt
- added simple sRGB support (Glenn R-P)
- easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
- all configurable options can be selected from command-line instead
- of having to edit pngconf.h (Glenn R-P)
- fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
- added more conditions for png_do_background, to avoid changing
- black pixels to background when a background is supplied and
- no pixels are transparent
- repaired PNG_NO_STDIO behaviour
- tested NODIV support and made it default behaviour (Greg Roelofs)
- added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
- regularized version numbering scheme and bumped shared-library major
- version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
-
-version 0.98 [January, 1998]
- cleaned up some typos in libpng.txt and in code documentation
- fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
- cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
- changed recommendation about file_gamma for PC images to .51 from .45,
- in example.c and libpng.txt, added comments to distinguish between
- screen_gamma, viewing_gamma, and display_gamma.
- changed all references to RFC1152 to read RFC1123 and changed the
- PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
- added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
- changed srgb_intent from png_byte to int to avoid compiler bugs
-
-version 0.99 [January 30, 1998]
- free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
- fixed a longstanding "packswap" bug in pngtrans.c
- fixed some inconsistencies in pngconf.h that prevented compiling with
- PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
- fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
- changed recommendation about file_gamma for PC images to .50 from .51 in
- example.c and libpng.txt, and changed file_gamma for sRGB images to .45
- added a number of functions to access information from the png structure
- png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
- added TARGET_MACOS similar to zlib-1.0.8
- define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
- added type casting to all png_malloc() function calls
-version 0.99a [January 31, 1998]
+ Changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
+ Added external C++ wrapper statements to png.h (Gilles Dauphin)
+ Allow PNG file to be read when some or all of file signature has already
+ been read from the beginning of the stream. ****This affects the size
+ of info_struct and invalidates all programs that use a shared libpng****
+ Fixed png_filler() declarations
+ Fixed? background color conversions
+ Fixed order of error function pointers to match documentation
+ Current chunk name is now available in png_struct to reduce the number
+ of nearly identical error messages (will simplify multi-lingual
+ support when available)
+ Try to get ready for unknown-chunk callback functions:
+ - previously read critical chunks are flagged, so the chunk handling
+ routines can determine if the chunk is in the right place
+ - all chunk handling routines have the same prototypes, so we will
+ be able to handle all chunks via a callback mechanism
+ Try to fix Linux "setjmp" buffer size problems
+ Removed png_large_malloc, png_large_free, and png_realloc functions.
+
+Version 0.95 [March, 1997]
+ Fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
+ Fixed bug in PNG file signature compares when start != 0
+ Changed parameter type of png_set_filler(...filler...) from png_byte
+ to png_uint_32
+ Added test for MACOS to ensure that both math.h and fp.h are not #included
+ Added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
+ Added "packswap" transformation, which changes the endianness of
+ packed-pixel bytes (Kevin Bracey)
+ Added "strip_alpha" transformation, which removes the alpha channel of
+ input images without using it (not necessarily a good idea)
+ Added "swap_alpha" transformation, which puts the alpha channel in front
+ of the color bytes instead of after
+ Removed all implicit variable tests which assume NULL == 0 (I think)
+ Changed several variables to "png_size_t" to show 16/32-bit limitations
+ Added new pCAL chunk read/write support
+ Added experimental filter selection weighting (Greg Roelofs)
+ Removed old png_set_rgbx() and png_set_xrgb() functions that have been
+ obsolete for about 2 years now (use png_set_filler() instead)
+ Added macros to read 16- and 32-bit ints directly from buffer, to be
+ used only on those systems that support it (namely PowerPC and 680x0)
+ With some testing, this may become the default for MACOS/PPC systems.
+ Only calculate CRC on data if we are going to use it
+ Added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
+ Added macros for simple libpng debugging output selectable at compile time
+ Removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
+ More description of info_struct in libpng.txt and png.h
+ More instructions in example.c
+ More chunk types tested in pngtest.c
+ Renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
+ png_set_<chunk>. We now have corresponding png_get_<chunk>
+ functions in pngget.c to get information in info_ptr. This isolates
+ the application from the internal organization of png_info_struct
+ (good for shared library implementations).
+
+Version 0.96 [May, 1997]
+ Fixed serious bug with < 8bpp images introduced in 0.95
+ Fixed 256-color transparency bug (Greg Roelofs)
+ Fixed up documentation (Greg Roelofs, Laszlo Nyul)
+ Fixed "error" in pngconf.h for Linux setjmp() behavior
+ Fixed DOS medium model support (Tim Wegner)
+ Fixed png_check_keyword() for case with error in static string text
+ Added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
+ Added typecasts to quiet compiler errors
+ Added more debugging info
+
+Version 0.97 [January, 1998]
+ Removed PNG_USE_OWN_CRC capability
+ Relocated png_set_crc_action from pngrutil.c to pngrtran.c
+ Fixed typecasts of "new_key", etc. (Andreas Dilger)
+ Added RFC 1152 [sic] date support
+ Fixed bug in gamma handling of 4-bit grayscale
+ Added 2-bit grayscale gamma handling (Glenn R-P)
+ Added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
+ Minor corrections in libpng.txt
+ Added simple sRGB support (Glenn R-P)
+ Easier conditional compiling, e.g.,
+ define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
+ all configurable options can be selected from command-line instead
+ of having to edit pngconf.h (Glenn R-P)
+ Fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
+ Added more conditions for png_do_background, to avoid changing
+ black pixels to background when a background is supplied and
+ no pixels are transparent
+ Repaired PNG_NO_STDIO behavior
+ Tested NODIV support and made it default behavior (Greg Roelofs)
+ Added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
+ Regularized version numbering scheme and bumped shared-library major
+ version number to 2 to avoid problems with libpng 0.89 apps
+ (Greg Roelofs)
+
+Version 0.98 [January, 1998]
+ Cleaned up some typos in libpng.txt and in code documentation
+ Fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
+ Cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
+ Changed recommendation about file_gamma for PC images to .51 from .45,
+ in example.c and libpng.txt, added comments to distinguish between
+ screen_gamma, viewing_gamma, and display_gamma.
+ Changed all references to RFC1152 to read RFC1123 and changed the
+ PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
+ Added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
+ Changed srgb_intent from png_byte to int to avoid compiler bugs
+
+Version 0.99 [January 30, 1998]
+ Free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
+ Fixed a longstanding "packswap" bug in pngtrans.c
+ Fixed some inconsistencies in pngconf.h that prevented compiling with
+ PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
+ Fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
+ Changed recommendation about file_gamma for PC images to .50 from .51 in
+ example.c and libpng.txt, and changed file_gamma for sRGB images to .45
+ Added a number of functions to access information from the png structure
+ png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
+ Added TARGET_MACOS similar to zlib-1.0.8
+ Define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
+ Added type casting to all png_malloc() function calls
+
+Version 0.99a [January 31, 1998]
Added type casts and parentheses to all returns that return a value.(Tim W.)
-version 0.99b [February 4, 1998]
+
+Version 0.99b [February 4, 1998]
Added type cast png_uint_32 on malloc function calls where needed.
Changed type of num_hist from png_uint_32 to int (same as num_palette).
Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
Renamed makefile.elf to makefile.lnx.
-version 0.99c [February 7, 1998]
+
+Version 0.99c [February 7, 1998]
More type casting. Removed erroneous overflow test in pngmem.c.
Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5.
-version 0.99d [February 11, 1998]
+
+Version 0.99d [February 11, 1998]
Renamed "far_to_near()" "png_far_to_near()"
Revised libpng.3
Version 99c "buffered" operations didn't work as intended. Replaced them
@@ -256,7 +267,8 @@ version 0.99d [February 11, 1998]
Check for overlength tRNS chunk present when indexed-color PLTE is read.
Cleaned up spelling errors in libpng.3/libpng.txt
Corrected a problem with png_get_tRNS() which returned undefined trans array
-version 0.99e [February 28, 1998]
+
+Version 0.99e [February 28, 1998]
Corrected png_get_tRNS() again.
Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
Touched up example.c to make more of it compileable, although the entire
@@ -266,53 +278,59 @@ version 0.99e [February 28, 1998]
Replaced pngtest.png with one created with zlib 1.1.1
Changed pngtest to report PASS even when file size is different (Jean-loup G.)
Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
-version 0.99f [March 5, 1998]
+
+Version 0.99f [March 5, 1998]
Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
Moved makefiles into a "scripts" directory, and added INSTALL instruction file
Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
Added pointers to "note on libpng versions" in makefile.lnx and README
Added row callback feature when reading and writing nonprogressive rows
- and added a test of this feature in pngtest.c
+ and added a test of this feature in pngtest.c
Added user transform callbacks, with test of the feature in pngtest.c
-version 0.99g [March 6, 1998, morning]
+
+Version 0.99g [March 6, 1998, morning]
Minor changes to pngtest.c to suppress compiler warnings.
Removed "beta" language from documentation.
-version 0.99h [March 6, 1998, evening]
+
+Version 0.99h [March 6, 1998, evening]
Minor changes to previous minor changes to pngtest.c
Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
- and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
+ and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
Added user transform capability
-version 1.00 [March 7, 1998]
+Version 1.00 [March 7, 1998]
Changed several typedefs in pngrutil.c
Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
- replaced "while(1)" with "for(;;)"
- added PNGARG() to prototypes in pngtest.c and removed some prototypes
- updated some of the makefiles (Tom Lane)
- changed some typedefs (s_start, etc.) in pngrutil.c
- fixed dimensions of "short_months" array in pngwrite.c
+ Replaced "while(1)" with "for(;;)"
+ Added PNGARG() to prototypes in pngtest.c and removed some prototypes
+ Updated some of the makefiles (Tom Lane)
+ Changed some typedefs (s_start, etc.) in pngrutil.c
+ Fixed dimensions of "short_months" array in pngwrite.c
Replaced ansi2knr.c with the one from jpeg-v6
-version 1.0.0 [March 8, 1998]
+Version 1.0.0 [March 8, 1998]
Changed name from 1.00 to 1.0.0 (Adam Costello)
Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
-version 1.0.0a [March 9, 1998]
+
+Version 1.0.0a [March 9, 1998]
Fixed three bugs in pngrtran.c to make gamma+background handling consistent
- (Greg Roelofs)
+ (Greg Roelofs)
Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
- for major, minor, and bugfix releases. This is 10001. (Adam Costello,
- Tom Lane)
+ for major, minor, and bugfix releases. This is 10001. (Adam Costello,
+ Tom Lane)
Make months range from 1-12 in png_convert_to_rfc1123
-version 1.0.0b [March 13, 1998]
+
+Version 1.0.0b [March 13, 1998]
Quieted compiler complaints about two empty "for" loops in pngrutil.c
Minor changes to makefile.s2x
Removed #ifdef/#endif around a png_free() in pngread.c
-version 1.0.1 [March 14, 1998]
+Version 1.0.1 [March 14, 1998]
Changed makefile.s2x to reduce security risk of using a relative pathname
Fixed some typos in the documentation (Greg).
Fixed a problem with value of "channels" returned by png_read_update_info()
-version 1.0.1a [April 21, 1998]
+
+Version 1.0.1a [April 21, 1998]
Optimized Paeth calculations by replacing abs() function calls with intrinsics
plus other loop optimizations. Improves avg decoding speed by about 20%.
Commented out i386istic "align" compiler flags in makefile.lnx.
@@ -326,19 +344,24 @@ version 1.0.1a [April 21, 1998]
Moved a misplaced pngrutil code block that truncates tRNS if it has more
than num_palette entries -- test was done before num_palette was defined.
Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
- Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
-version 1.0.1b [May 2, 1998]
+ Changed compiler flags in makefile.wat for better optimization
+ (Pawel Mrochen).
+
+Version 1.0.1b [May 2, 1998]
Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
Relocated the png_composite macros from pngrtran.c to png.h (Greg).
Added makefile.sco (contributed by Mike Hopkirk).
Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
- More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
- More work on loop optimization which may help when compiled with C++ compilers.
+ More work on the Paeth-filtering, achieving imperceptible speedup
+ (A Kleinert).
+ More work on loop optimization which may help when compiled with C++
+ compilers.
Added warnings when people try to use transforms they've defined out.
Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
-version 1.0.1c [May 11, 1998]
+
+Version 1.0.1c [May 11, 1998]
Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
filler bytes should have been 0xff instead of 0xf.
Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
@@ -350,7 +373,8 @@ version 1.0.1c [May 11, 1998]
to remove unwanted capabilities via the compile line
Made some corrections to grammar (which, it's) in documentation (Greg).
Corrected example.c, use of row_pointers in png_write_image().
-version 1.0.1d [May 24, 1998]
+
+Version 1.0.1d [May 24, 1998]
Corrected several statements that used side effects illegally in pngrutil.c
and pngtrans.c, that were introduced in version 1.0.1b
Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
@@ -360,7 +384,8 @@ version 1.0.1d [May 24, 1998]
Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
Changed several loops from count-down to count-up, for consistency.
-version 1.0.1e [June 6, 1998]
+
+Version 1.0.1e [June 6, 1998]
Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
added warnings when people try to set png_read_fn and png_write_fn in
the same structure.
@@ -377,9 +402,10 @@ version 1.0.1e [June 6, 1998]
PNGTEST_DEBUG_MEM feature.
Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
-version 1.0.2 [June 14, 1998]
+Version 1.0.2 [June 14, 1998]
Fixed two bugs in makefile.bor .
-version 1.0.2a [December 30, 1998]
+
+Version 1.0.2a [December 30, 1998]
Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
Fixed a bug in png_do_filler() that made it fail to write filler bytes in
the left-most pixel of each row (Kevin Bracey).
@@ -401,23 +427,26 @@ version 1.0.2a [December 30, 1998]
Added png_get_copyright() and png_get_header_version() functions.
Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
Added information about debugging in libpng.txt and libpng.3 .
- Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+ Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and
+ makefile.sco.
Removed lines after Dynamic Dependencies" in makefile.aco .
Revised makefile.dec to make a shared library (Jeremie Petit).
Removed trailing blanks from all files.
-version 1.0.2a [January 6, 1999]
+
+Version 1.0.2a [January 6, 1999]
Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
which is obsolete.
-version 1.0.3 [January 14, 1999]
+Version 1.0.3 [January 14, 1999]
Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
-version 1.0.3a [August 12, 1999]
+
+Version 1.0.3a [August 12, 1999]
Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
- if an attempt is made to read an interlaced image when it's not supported.
+ if an attempt is made to read an interlaced image when it's not supported.
Added check if png_ptr->trans is defined before freeing it in pngread.c
Modified the Y2K statement to include versions back to version 0.71
Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
@@ -425,7 +454,7 @@ version 1.0.3a [August 12, 1999]
Replaced leading blanks with tab characters in makefile.hux
Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
Changed (float)red and (float)green to (double)red, (double)green
- in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+ in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
Updated documentation to refer to the PNG-1.2 specification.
@@ -442,13 +471,15 @@ version 1.0.3a [August 12, 1999]
Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
consistent with PNG-1.2, and allow variance of 500 before complaining.
Added assembler code contributed by Intel in file pngvcrd.c and modified
- makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+ makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation,
+ Gilles Vollant)
Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
Added some aliases for png_set_expand() in pngrtran.c, namely
png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
(Greg Roelofs, in "PNG: The Definitive Guide").
Added makefile.beo for BEOS on X86, contributed by Sander Stok.
-version 1.0.3b [August 26, 1999]
+
+Version 1.0.3b [August 26, 1999]
Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
Changed leading blanks to tabs in all makefiles.
Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
@@ -460,12 +491,13 @@ version 1.0.3b [August 26, 1999]
negative shift distance, whose results are undefined in the C language.
Added a check in pngset.c to prevent writing multiple tIME chunks.
Added a check in pngwrite.c to detect invalid small window_bits sizes.
-version 1.0.3d [September 4, 1999]
+
+Version 1.0.3d [September 4, 1999]
Fixed type casting of igamma in pngrutil.c
Added new png_expand functions to scripts/pngdef.pas and pngos2.def
Added a demo read_user_transform_fn that examines the row filters in pngtest.c
-version 1.0.4 [September 24, 1999]
+Version 1.0.4 [September 24, 1999, not distributed publicly]
Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
Made several minor corrections to pngtest.c
@@ -479,24 +511,31 @@ version 1.0.4 [September 24, 1999]
assembler code) and makefile.vcwin32 (doesn't).
Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
Added a copy of pngnow.png to the distribution.
-version 1.0.4a [September 25, 1999]
+
+Version 1.0.4a [September 25, 1999]
Increase max_pixel_depth in pngrutil.c if a user transform needs it.
Changed several division operations to right-shifts in pngvcrd.c
-version 1.0.4b [September 30, 1999]
+
+Version 1.0.4b [September 30, 1999]
Added parentheses in line 3732 of pngvcrd.c
Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
-version 1.0.4c [October 1, 1999]
+
+Version 1.0.4c [October 1, 1999]
Added a "png_check_version" function in png.c and pngtest.c that will generate
a helpful compiler error if an old png.h is found in the search path.
Changed type of png_user_transform_depth|channels from int to png_byte.
-version 1.0.4d [October 6, 1999]
+ Added "Libpng is OSI Certified Open Source Software" statement to png.h
+
+Version 1.0.4d [October 6, 1999]
Changed 0.45 to 0.45455 in png_set_sRGB()
Removed unused PLTE entries from pngnow.png
Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
-version 1.0.4e [October 10, 1999]
+
+Version 1.0.4e [October 10, 1999]
Fixed sign error in pngvcrd.c (Greg Roelofs)
Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
-version 1.0.4f [October 15, 1999]
+
+Version 1.0.4f [October 15, 1999]
Surrounded example.c code with #if 0 .. #endif to prevent people from
inadvertently trying to compile it.
Changed png_get_header_version() from a function to a macro in png.h
@@ -504,9 +543,10 @@ version 1.0.4f [October 15, 1999]
Removed some pointless "ptr = NULL" in pngmem.c
Added a "contrib" directory containing the source code from Greg's book.
-version 1.0.5 [October 15, 1999]
+Version 1.0.5 [October 15, 1999]
Minor editing of the INSTALL and README files.
-version 1.0.5a [October 23, 1999]
+
+Version 1.0.5a [October 23, 1999]
Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
Further optimization and bugfix of pngvcrd.c
@@ -514,14 +554,16 @@ version 1.0.5a [October 23, 1999]
text_ptr structure. Instead, it makes its own copy.
Created separate write_end_info_struct in pngtest.c for a more severe test.
Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
-version 1.0.5b [November 23, 1999]
+
+Version 1.0.5b [November 23, 1999]
Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
PNG_FLAG_WROTE_tIME from flags to mode.
Added png_write_info_before_PLTE() function.
Fixed some typecasting in contrib/gregbook/*.c
Updated scripts/makevms.com and added makevms.com to contrib/gregbook
and contrib/pngminus (Martin Zinser)
-version 1.0.5c [November 26, 1999]
+
+Version 1.0.5c [November 26, 1999]
Moved png_get_header_version from png.h to png.c, to accommodate ansi2knr.
Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
accommodate making DLL's: Moved usr_png_ver from global variable to function
@@ -534,21 +576,23 @@ version 1.0.5c [November 26, 1999]
Removed some extraneous "-I" from contrib/pngminus/makefile.std
Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
-version 1.0.5d [November 29, 1999]
+
+Version 1.0.5d [November 29, 1999]
Add type cast (png_const_charp) two places in png.c
Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
to applications a macro "PNG_USE_LOCAL_ARRAYS".
- Remove all the new declarations with #ifdef/#endif when
+ comment out (with #ifdef) all the new declarations when
PNG_USE_GLOBAL_ARRAYS is defined.
Added PNG_EXPORT_VAR macro to accommodate making DLL's.
-version 1.0.5e [November 30, 1999]
+
+Version 1.0.5e [November 30, 1999]
Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
structure; refactored the inflate/deflate support to make adding new chunks
with trailing compressed parts easier in the future, and added new functions
png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
- NOTE: Applications that write text chunks MUST define png_text->lang
+ NOTE: Applications that write text chunks MUST define png_text->lang
before calling png_set_text(). It must be set to NULL if you want to
write tEXt or zTXt chunks. If you want your application to be able to
run with older versions of libpng, use
@@ -563,18 +607,21 @@ version 1.0.5e [November 30, 1999]
PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
macros, leaving the separate macros also available.
Removed comments on #endifs at the end of many short, non-nested #if-blocks.
-version 1.0.5f [December 6, 1999]
+
+Version 1.0.5f [December 6, 1999]
Changed makefile.solaris to issue a warning about potential problems when
the ucb "ld" is in the path ahead of the ccs "ld".
Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
Added sCAL chunk support (Eric S. Raymond).
-version 1.0.5g [December 7, 1999]
+
+Version 1.0.5g [December 7, 1999]
Fixed "png_free_spallettes" typo in png.h
Added code to handle new chunks in pngpread.c
Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
Added "translated_key" to png_text structure and png_write_iTXt().
Added code in pngwrite.c to work around a newly discovered zlib bug.
-version 1.0.5h [December 10, 1999]
+
+Version 1.0.5h [December 10, 1999]
NOTE: regarding the note for version 1.0.5e, the following must also
be included in your code:
png_text[i].translated_key = NULL;
@@ -582,7 +629,8 @@ version 1.0.5h [December 10, 1999]
Option to eliminate all floating point support was added. Some new
fixed-point functions such as png_set_gAMA_fixed() were added.
Expanded tabs and removed trailing blanks in source files.
-version 1.0.5i [December 13, 1999]
+
+Version 1.0.5i [December 13, 1999]
Added some type casts to silence compiler warnings.
Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
Removed leading blanks from a #define in pngvcrd.c
@@ -594,7 +642,8 @@ version 1.0.5i [December 13, 1999]
Added png_free_hIST() function.
Various patches to fix bugs in the sCAL and integer cHRM processing,
and to add some convenience macros for use with sCAL.
-version 1.0.5j [December 21, 1999]
+
+Version 1.0.5j [December 21, 1999]
Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
around buggy compilers.
Added new type "png_fixed_point" for integers that hold float*100000 values
@@ -610,7 +659,8 @@ version 1.0.5j [December 21, 1999]
and to write the iTXt chunk after IDAT if it appears in the end_ptr.
Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
Reversed the order of trying to write floating-point and fixed-point gAMA.
-version 1.0.5k [December 27, 1999]
+
+Version 1.0.5k [December 27, 1999]
Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
Added png_handle_as_unknown() function (Glenn)
Added png_free_chunk_list() function and chunk_list and num_chunk_list members
@@ -621,33 +671,41 @@ version 1.0.5k [December 27, 1999]
Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
-version 1.0.5l [January 1, 2000]
+
+Version 1.0.5l [January 1, 2000]
Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
for setting a callback function to handle unknown chunks and for
retrieving the associated user pointer (Glenn).
-version 1.0.5m [January 7, 2000]
+
+Version 1.0.5m [January 7, 2000]
Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
-version 1.0.5n [January 9, 2000]
+
+Version 1.0.5n [January 9, 2000]
Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
own memory for info_ptr->palette. This makes it safe for the calling
application to free its copy of the palette any time after it calls
png_set_PLTE().
-version 1.0.5o [January 20, 2000]
+
+Version 1.0.5o [January 20, 2000]
Cosmetic changes only (removed some trailing blanks and TABs)
-version 1.0.5p [January 31, 2000]
+
+Version 1.0.5p [January 31, 2000]
Renamed pngdll.mak to makefile.bd32
Cosmetic changes in pngtest.c
-version 1.0.5q [February 5, 2000]
+
+Version 1.0.5q [February 5, 2000]
Relocated the makefile.solaris warning about PATH problems.
Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
Revised makefile.gcmmx
Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
-version 1.0.5r [February 7, 2000]
+
+Version 1.0.5r [February 7, 2000]
Removed superfluous prototype for png_get_itxt from png.h
Fixed a bug in pngrtran.c that improperly expanded the background color.
Return *num_text=0 from png_get_text() when appropriate, and fix documentation
of png_get_text() in libpng.txt/libpng.3.
-version 1.0.5s [February 18, 2000]
+
+Version 1.0.5s [February 18, 2000]
Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
new error handler that's planned for the next libpng release, and changed
example.c, pngtest.c, and contrib programs to use this macro.
@@ -666,7 +724,8 @@ version 1.0.5s [February 18, 2000]
Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
Modified png_read_png() to allocate info_ptr->row_pointers only if it
hasn't already been allocated.
-version 1.0.5t [March 4, 2000]
+
+Version 1.0.5t [March 4, 2000]
Changed png_jmp_env() migration aiding macro to png_jmpbuf().
Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
@@ -675,13 +734,15 @@ version 1.0.5t [March 4, 2000]
a 24-bit visual if one is available, and to allow abbreviated options.
Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
-version 1.0.5u [March 5, 2000]
+
+Version 1.0.5u [March 5, 2000]
Simplified the code that detects old png.h in png.c and pngtest.c
Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
Increased precision of rgb_to_gray calculations from 8 to 15 bits and
added png_set_rgb_to_gray_fixed() function.
Added makefile.bc32 (32-bit Borland C++, C mode)
-version 1.0.5v [March 11, 2000]
+
+Version 1.0.5v [March 11, 2000]
Added some parentheses to the png_jmpbuf macro definition.
Updated references to the zlib home page, which has moved to freesoftware.com.
Corrected bugs in documentation regarding png_read_row() and png_write_row().
@@ -689,10 +750,11 @@ version 1.0.5v [March 11, 2000]
Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
-version 1.0.6 [March 20, 2000]
+Version 1.0.6 [March 20, 2000]
Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
Added makefile.sggcc (SGI IRIX with gcc)
-version 1.0.6d [April 7, 2000]
+
+Version 1.0.6d [April 7, 2000]
Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
Added data_length parameter to png_decompress_chunk() function
Revised documentation to remove reference to abandoned png_free_chnk functions
@@ -701,7 +763,8 @@ version 1.0.6d [April 7, 2000]
Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
Added a check for info_ptr->free_me&PNG_FREE_TEXT when freeing text in png.c
Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
-version 1.0.6e [April 9, 2000]
+
+Version 1.0.6e [April 9, 2000]
Added png_data_freer() function.
In the code that checks for over-length tRNS chunks, added check of
info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
@@ -712,25 +775,29 @@ version 1.0.6e [April 9, 2000]
is defined.
Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
and mentioned the purposes of the two macros in libpng.txt/libpng.3.
-version 1.0.6f [April 14, 2000]
+
+Version 1.0.6f [April 14, 2000]
Revised png_set_iCCP() and png_set_rows() to avoid prematurely freeing data.
Add checks in png_set_text() for NULL members of the input text structure.
Revised libpng.txt/libpng.3.
- Removed superfluous prototype for png_set_itxt from png.h
+ Removed superfluous prototype for png_set_iTXt from png.h
Removed "else" from pngread.c, after png_error(), and changed "0" to "length".
Changed several png_errors about malformed ancillary chunks to png_warnings.
-version 1.0.6g [April 24, 2000]
+
+Version 1.0.6g [April 24, 2000]
Added png_pass-* arrays to pnggccrd.c when PNG_USE_LOCAL_ARRAYS is defined.
Relocated paragraph about png_set_background() in libpng.3/libpng.txt
and other revisions (Matthias Benckmann)
Relocated info_ptr->free_me, png_ptr->free_me, and other info_ptr and
png_ptr members to restore binary compatibility with libpng-1.0.5
(breaks compatibility with libpng-1.0.6).
-version 1.0.6h [April 24, 2000]
+
+Version 1.0.6h [April 24, 2000]
Changed shared library so-number pattern from 2.x.y.z to xy.z (this builds
libpng.so.10 & libpng.so.10.6h instead of libpng.so.2 & libpng.so.2.1.0.6h)
This is a temporary change for test purposes.
-version 1.0.6i [May 2, 2000]
+
+Version 1.0.6i [May 2, 2000]
Rearranged some members at the end of png_info and png_struct, to put
unknown_chunks_num and free_me within the original size of the png_structs
and free_me, png_read_user_fn, and png_free_fn within the original png_info,
@@ -755,22 +822,25 @@ version 1.0.6i [May 2, 2000]
generate a libpng error if the modes aren't set and PNG_LEGACY_SUPPORTED
was not defined.
Added makefile.intel and updated makefile.watcom (Pawel Mrochen)
-version 1.0.6j [May 3, 2000]
+
+Version 1.0.6j [May 3, 2000]
Overloaded png_read_init() and png_write_init() with macros that convert
calls to png_read_init_2() or png_write_init_2() that check the version
and structure sizes.
-version 1.0.7beta11 [May 7, 2000]
+
+Version 1.0.7beta11 [May 7, 2000]
Removed the new PNG_CREATED_READ_STRUCT and PNG_CREATED_WRITE_STRUCT modes
which are no longer used.
Eliminated the three new members of png_text when PNG_LEGACY_SUPPORTED is
- defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXT_SUPPORTED
+ defined or when neither PNG_READ_iTXt_SUPPORTED nor PNG_WRITE_iTXt_SUPPORTED
is defined.
Made PNG_NO_READ|WRITE_iTXt the default setting, to avoid memory
overrun when old applications fill the info_ptr->text structure directly.
Added PNGAPI macro, and added it to the definitions of all exported functions.
Relocated version macro definitions ahead of the includes of zlib.h and
pngconf.h in png.h.
-version 1.0.7beta12 [May 12, 2000]
+
+Version 1.0.7beta12 [May 12, 2000]
Revised pngset.c to avoid a problem with expanding the png_debug macro.
Deleted some extraneous defines from pngconf.h
Made PNG_NO_CONSOLE_IO the default condition when PNG_BUILD_DLL is defined.
@@ -778,7 +848,8 @@ version 1.0.7beta12 [May 12, 2000]
Added png_access_version_number() function.
Check for mask&PNG_FREE_CHNK (for TEXT, SCAL, PCAL) in png_free_data().
Expanded libpng.3/libpng.txt information about png_data_freer().
-version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
+
+Version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
Changed pnggccrd.c and pngvcrd.c to handle bad adaptive filter types as
warnings instead of errors, as pngrutil.c does.
Set the PNG_INFO_IDAT valid flag in png_set_rows() so png_write_png()
@@ -790,7 +861,8 @@ version 1.0.7beta14 [May 17, 2000] (beta13 was not published)
Removed info_ptr->valid tests from png_free_data(), as in version 1.0.5.
Added png_set_invalid() function.
Fixed incorrect illustrations of png_destroy_write_struct() in example.c.
-version 1.0.7beta15 [May 30, 2000]
+
+Version 1.0.7beta15 [May 30, 2000]
Revised the deliberately erroneous Linux setjmp code in pngconf.h to produce
fewer error messages.
Rearranged checks for Z_OK to check the most likely path first in pngpread.c
@@ -802,9 +874,11 @@ version 1.0.7beta15 [May 30, 2000]
Fixed some bugs in the unused PNG_INCH_CONVERSIONS functions in pngget.c
Set each pointer to NULL after freeing it in png_free_data().
Worked around a problem in pngconf.h; AIX's strings.h defines an "index"
- macro that conflicts with libpng's png_color_16.index. (Dimitri Papadapoulos)
+ macro that conflicts with libpng's png_color_16.index. (Dimitri
+ Papadapoulos)
Added "msvc" directory with MSVC++ project files (Simon-Pierre Cadieux).
-version 1.0.7beta16 [June 4, 2000]
+
+Version 1.0.7beta16 [June 4, 2000]
Revised the workaround of AIX string.h "index" bug.
Added a check for overlength PLTE chunk in pngrutil.c.
Added PNG_NO_POINTER_INDEXING macro to use array-indexing instead of pointer
@@ -814,49 +888,58 @@ version 1.0.7beta16 [June 4, 2000]
Added PNG_USE_DLL macro.
Revised the copyright/disclaimer/license notice.
Added contrib/msvctest directory
-version 1.0.7rc1 [June 9, 2000]
+
+Version 1.0.7rc1 [June 9, 2000]
Corrected the definition of PNG_TRANSFORM_INVERT_ALPHA (0x0400 not 0x0200)
Added contrib/visupng directory (Willem van Schaik)
-version 1.0.7beta18 [June 23, 2000]
+
+Version 1.0.7beta18 [June 23, 2000]
Revised PNGAPI definition, and pngvcrd.c to work with __GCC__
and do not redefine PNGAPI if it is passed in via a compiler directive.
Revised visupng/PngFile.c to remove returns from within the Try block.
Removed leading underscores from "_PNG_H" and "_PNG_SAVE_BSD_SOURCE" macros.
Updated contrib/visupng/cexcept.h to version 1.0.0.
Fixed bugs in pngwrite.c and pngwutil.c that prevented writing iCCP chunks.
-version 1.0.7rc2 [June 28, 2000]
+
+Version 1.0.7rc2 [June 28, 2000]
Updated license to include disclaimers required by UCITA.
Fixed "DJBPP" typo in pnggccrd.c introduced in beta18.
-version 1.0.7 [July 1, 2000]
+Version 1.0.7 [July 1, 2000]
Revised the definition of "trans_values" in libpng.3/libpng.txt
-version 1.0.8beta1 [July 8, 2000]
+
+Version 1.0.8beta1 [July 8, 2000]
Added png_free(png_ptr, key) two places in pngpread.c to stop memory leaks.
Changed PNG_NO_STDIO to PNG_NO_CONSOLE_IO, several places in pngrutil.c and
- pngwutil.c.
+ pngwutil.c.
Changed PNG_EXPORT_VAR to use PNG_IMPEXP, in pngconf.h.
Removed unused "#include <assert.h>" from png.c
Added WindowsCE support.
Revised pnggccrd.c to work with gcc-2.95.2 and in the Cygwin environment.
-version 1.0.8beta2 [July 10, 2000]
+
+Version 1.0.8beta2 [July 10, 2000]
Added project files to the wince directory and made further revisions
- of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
-version 1.0.8beta3 [July 11, 2000]
+ of pngtest.c, pngrio.c, and pngwio.c in support of WindowsCE.
+
+Version 1.0.8beta3 [July 11, 2000]
Only set the PNG_FLAG_FREE_TRNS or PNG_FREE_TRNS flag in png_handle_tRNS()
- for indexed-color input files to avoid potential double-freeing trans array
- under some unusual conditions; problem was introduced in version 1.0.6f.
+ for indexed-color input files to avoid potential double-freeing trans array
+ under some unusual conditions; problem was introduced in version 1.0.6f.
Further revisions to pngtest.c and files in the wince subdirectory.
-version 1.0.8beta4 [July 14, 2000]
+
+Version 1.0.8beta4 [July 14, 2000]
Added the files pngbar.png and pngbar.jpg to the distribution.
Added makefile.cygwin, and cygwin support in pngconf.h
Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
-version 1.0.8rc1 [July 16, 2000]
+
+Version 1.0.8rc1 [July 16, 2000]
Revised png_debug() macros and statements to eliminate compiler warnings.
-version 1.0.8 [July 24, 2000]
+Version 1.0.8 [July 24, 2000]
Added png_flush() in pngwrite.c, after png_write_IEND().
Updated makefile.hpux to build a shared library.
-version 1.0.9beta1 [November 10, 2000]
+
+Version 1.0.9beta1 [November 10, 2000]
Fixed typo in scripts/makefile.hpux
Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
@@ -875,59 +958,72 @@ version 1.0.9beta1 [November 10, 2000]
Revised makefile.cygwin
Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
-version 1.0.9beta2 [November 19, 2000]
+
+Version 1.0.9beta2 [November 19, 2000]
Renamed the "dll" subdirectory "projects".
Added borland project files to "projects" subdirectory.
Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
Add error message in png_set_compression_buffer_size() when malloc fails.
-version 1.0.9beta3 [November 23, 2000]
+
+Version 1.0.9beta3 [November 23, 2000]
Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
Removed the png_flush() in pngwrite.c that crashes some applications
that don't set png_output_flush_fn.
Added makefile.macosx and makefile.aix to scripts directory.
-version 1.0.9beta4 [December 1, 2000]
+
+Version 1.0.9beta4 [December 1, 2000]
Change png_chunk_warning to png_warning in png_check_keyword().
Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
-version 1.0.9beta5 [December 15, 2000]
+
+Version 1.0.9beta5 [December 15, 2000]
Added support for filter method 64 (for PNG datastreams embedded in MNG).
-version 1.0.9beta6 [December 18, 2000]
+
+Version 1.0.9beta6 [December 18, 2000]
Revised png_set_filter() to accept filter method 64 when appropriate.
Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
help prevent applications from using MNG features in PNG datastreams.
Added png_permit_mng_features() function.
Revised libpng.3/libpng.txt. Changed "filter type" to "filter method".
-version 1.0.9rc1 [December 23, 2000]
+
+Version 1.0.9rc1 [December 23, 2000]
Revised test for PNG_HAVE_PNG_SIGNATURE in pngrutil.c
Fixed error handling of unknown compression type in png_decompress_chunk().
In pngconf.h, define __cdecl when _MSC_VER is defined.
-version 1.0.9beta7 [December 28, 2000]
+
+Version 1.0.9beta7 [December 28, 2000]
Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
Revised memory management in png_set_hIST and png_handle_hIST in a backward
compatible manner. PLTE and tRNS were revised similarly.
Revised the iCCP chunk reader to ignore trailing garbage.
-version 1.0.9beta8 [January 12, 2001]
+
+Version 1.0.9beta8 [January 12, 2001]
Moved pngasmrd.h into pngconf.h.
Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
-version 1.0.9beta9 [January 15, 2001]
+
+Version 1.0.9beta9 [January 15, 2001]
Added png_set_invalid, png_permit_mng_features, and png_mmx_supported to
wince and msvc project module definition files.
Minor revision of makefile.cygwin.
Fixed bug with progressive reading of narrow interlaced images in pngpread.c
-version 1.0.9beta10 [January 16, 2001]
+
+Version 1.0.9beta10 [January 16, 2001]
Do not typedef png_FILE_p in pngconf.h when PNG_NO_STDIO is defined.
Fixed "png_mmx_supported" typo in project definition files.
-version 1.0.9beta11 [January 19, 2001]
+
+Version 1.0.9beta11 [January 19, 2001]
Updated makefile.sgi to make shared library.
Removed png_mmx_support() function and disabled PNG_MNG_FEATURES_SUPPORTED
by default, for the benefit of DLL forward compatibility. These will
be re-enabled in version 1.2.0.
-version 1.0.9rc2 [January 22, 2001]
+
+Version 1.0.9rc2 [January 22, 2001]
Revised cygwin support.
-version 1.0.9 [January 31, 2001]
+Version 1.0.9 [January 31, 2001]
Added check of cygwin's ALL_STATIC in pngconf.h
Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
-version 1.0.10beta1 [March 14, 2001]
+
+Version 1.0.10beta1 [March 14, 2001]
Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
Reformatted libpng.3 to eliminate bad line breaks.
Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
@@ -940,33 +1036,39 @@ version 1.0.10beta1 [March 14, 2001]
Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
Added warnings when retrieving or setting gamma=0.
Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
-version 1.0.10rc1 [March 23, 2001]
+
+Version 1.0.10rc1 [March 23, 2001]
Changed all instances of memcpy, strcpy, and strlen to png_memcpy, png_strcpy,
and png_strlen.
Revised png_mmx_supported() function in pnggccrd.c to return proper value.
Fixed bug in progressive reading (pngpread.c) with small images (height < 8).
-version 1.0.10 [March 30, 2001]
+Version 1.0.10 [March 30, 2001]
Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
Added beos project files (Chris Herborth)
-version 1.0.11beta1 [April 3, 2001]
+
+Version 1.0.11beta1 [April 3, 2001]
Added type casts on several png_malloc() calls (Dimitri Papadapoulos).
Removed a no-longer needed AIX work-around from pngconf.h
Changed several "//" single-line comments to C-style in pnggccrd.c
-version 1.0.11beta2 [April 11, 2001]
+
+Version 1.0.11beta2 [April 11, 2001]
Removed PNGAPI from several functions whose prototypes did not have PNGAPI.
Updated scripts/pngos2.def
-version 1.0.11beta3 [April 14, 2001]
+
+Version 1.0.11beta3 [April 14, 2001]
Added checking the results of many instances of png_malloc() for NULL
-version 1.0.11beta4 [April 20, 2001]
+
+Version 1.0.11beta4 [April 20, 2001]
Undid the changes from version 1.0.11beta3. Added a check for NULL return
from user's malloc_fn().
Removed some useless type casts of the NULL pointer.
Added makefile.netbsd
-version 1.0.11 [April 27, 2001]
+Version 1.0.11 [April 27, 2001]
Revised makefile.netbsd
-version 1.0.12beta1 [May 14, 2001]
+
+Version 1.0.12beta1 [May 14, 2001]
Test for Windows platform in pngconf.h when including malloc.h (Emmanuel Blot)
Updated makefile.cygwin and handling of Cygwin's ALL_STATIC in pngconf.h
Added some never-to-be-executed code in pnggccrd.c to quiet compiler warnings.
@@ -974,66 +1076,76 @@ version 1.0.12beta1 [May 14, 2001]
libpng will reallocate the png_struct and info_struct if they are too small.
This retains future binary compatibility for old applications written for
libpng-0.88 and earlier.
-version 1.2.0beta1 [May 6, 2001]
+
+Version 1.2.0beta1 [May 6, 2001]
Bumped DLLNUM to 2.
Re-enabled PNG_MNG_FEATURES_SUPPORTED and enabled PNG_ASSEMBLER_CODE_SUPPORTED
by default.
Added runtime selection of MMX features.
Added png_set_strip_error_numbers function and related macros.
-version 1.2.0beta2 [May 7, 2001]
+
+Version 1.2.0beta2 [May 7, 2001]
Finished merging 1.2.0beta1 with version 1.0.11
Added a check for attempts to read or write PLTE in grayscale PNG datastreams.
-version 1.2.0beta3 [May 17, 2001]
+
+Version 1.2.0beta3 [May 17, 2001]
Enabled user memory function by default.
Modified png_create_struct so it passes user mem_ptr to user memory allocator.
Increased png_mng_features flag from png_byte to png_uint_32.
Bumped shared-library (so-number) and dll-number to 3.
-version 1.2.0beta4 [June 23, 2001]
+
+Version 1.2.0beta4 [June 23, 2001]
Check for missing profile length field in iCCP chunk and free chunk_data
- in case of truncated iCCP chunk.
+ in case of truncated iCCP chunk.
Bumped shared-library number to 3 in makefile.sgi and makefile.sggcc
Bumped dll-number from 2 to 3 in makefile.cygwin
Revised contrib/gregbook/rpng*-x.c to avoid a memory leak and to exit cleanly
- if user attempts to run it on an 8-bit display.
+ if user attempts to run it on an 8-bit display.
Updated contrib/gregbook
Use png_malloc instead of png_zalloc to allocate palette in pngset.c
Updated makefile.ibmc
Added some typecasts to eliminate gcc 3.0 warnings. Changed prototypes
- of png_write_oFFS width and height from png_uint_32 to png_int_32.
+ of png_write_oFFS width and height from png_uint_32 to png_int_32.
Updated example.c
Revised prototypes for png_debug_malloc and png_debug_free in pngtest.c
-version 1.2.0beta5 [August 8, 2001]
+
+Version 1.2.0beta5 [August 8, 2001]
Revised contrib/gregbook
Revised makefile.gcmmx
Revised pnggccrd.c to conditionally compile some thread-unsafe code only
- when PNG_THREAD_UNSAFE_OK is defined.
+ when PNG_THREAD_UNSAFE_OK is defined.
Added tests to prevent pngwutil.c from writing a bKGD or tRNS chunk with
- value exceeding 2^bit_depth-1
+ value exceeding 2^bit_depth-1
Revised makefile.sgi and makefile.sggcc
Replaced calls to fprintf(stderr,...) with png_warning() in pnggccrd.c
Removed restriction that do_invert_mono only operate on 1-bit opaque files
-version 1.2.0 [September 1, 2001]
+Version 1.2.0 [September 1, 2001]
Changed a png_warning() to png_debug() in pnggccrd.c
Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
-version 1.2.1beta1 [October 19, 2001]
+
+Version 1.2.1beta1 [October 19, 2001]
Revised makefile.std in contrib/pngminus
Include background_1 in png_struct regardless of gamma support.
Revised makefile.netbsd and makefile.macosx, added makefile.darwin.
Revised example.c to provide more details about using row_callback().
-version 1.2.1beta2 [October 25, 2001]
+
+Version 1.2.1beta2 [October 25, 2001]
Added type cast to each NULL appearing in a function call, except for
WINCE functions.
Added makefile.so9.
-version 1.2.1beta3 [October 27, 2001]
+
+Version 1.2.1beta3 [October 27, 2001]
Removed type casts from all NULLs.
Simplified png_create_struct_2().
-version 1.2.1beta4 [November 7, 2001]
+
+Version 1.2.1beta4 [November 7, 2001]
Revised png_create_info_struct() and png_creat_struct_2().
Added error message if png_write_info() was omitted.
Type cast NULLs appearing in function calls when _NO_PROTO or
PNG_TYPECAST_NULL is defined.
-version 1.2.1rc1 [November 24, 2001]
+
+Version 1.2.1rc1 [November 24, 2001]
Type cast NULLs appearing in function calls except when PNG_NO_TYPECAST_NULL
is defined.
Changed typecast of "size" argument to png_size_t in pngmem.c calls to
@@ -1042,14 +1154,16 @@ version 1.2.1rc1 [November 24, 2001]
Updated makefile.sgi to recognize LIBPATH and INCPATH.
Updated various makefiles so "make clean" does not remove previous major
version of the shared library.
-version 1.2.1rc2 [December 4, 2001]
+
+Version 1.2.1rc2 [December 4, 2001]
Always allocate 256-entry internal palette, hist, and trans arrays, to
avoid out-of-bounds memory reference caused by invalid PNG datastreams.
Added a check for prefix_length > data_length in iCCP chunk handler.
-version 1.2.1 [December 7, 2001]
+Version 1.2.1 [December 7, 2001]
None.
-version 1.2.2beta1 [February 22, 2002]
+
+Version 1.2.2beta1 [February 22, 2002]
Fixed a bug with reading the length of iCCP profiles (Larry Reeves).
Revised makefile.linux, makefile.gcmmx, and makefile.sgi to generate
libpng.a, libpng12.so (not libpng.so.3), and libpng12/png.h
@@ -1059,13 +1173,15 @@ version 1.2.2beta1 [February 22, 2002]
Revised calls to png_create_read_struct() and png_create_write_struct()
for simpler debugging.
Revised png_zalloc() so zlib handles errors (uses PNG_FLAG_MALLOC_NULL_MEM_OK)
-version 1.2.2beta2 [February 23, 2002]
+
+Version 1.2.2beta2 [February 23, 2002]
Check chunk_length and idat_size for invalid (over PNG_MAX_UINT) lengths.
Check for invalid image dimensions in png_get_IHDR.
Added missing "fi;" in the install target of the SGI makefiles.
Added install-static to all makefiles that make shared libraries.
Always do gamma compensation when image is partially transparent.
-version 1.2.2beta3 [March 7, 2002]
+
+Version 1.2.2beta3 [March 7, 2002]
Compute background.gray and background_1.gray even when color_type is RGB
in case image gets reduced to gray later.
Modified shared-library makefiles to install pkgconfig/libpngNN.pc.
@@ -1075,12 +1191,14 @@ version 1.2.2beta3 [March 7, 2002]
Added install-shared target to all makefiles that make shared libraries.
Stopped a double free of palette, hist, and trans when not using free_me.
Added makefile.32sunu for Sun Ultra 32 and makefile.64sunu for Sun Ultra 64.
-version 1.2.2beta4 [March 8, 2002]
+
+Version 1.2.2beta4 [March 8, 2002]
Compute background.gray and background_1.gray even when color_type is RGB
in case image gets reduced to gray later (Jason Summers).
Relocated a misplaced /bin/rm in the "install-shared" makefile targets
Added PNG_1_0_X macro which can be used to build a 1.0.x-compatible library.
-version 1.2.2beta5 [March 26, 2002]
+
+Version 1.2.2beta5 [March 26, 2002]
Added missing PNGAPI to several function definitions.
Check for invalid bit_depth or color_type in png_get_IHDR(), and
check for missing PLTE or IHDR in png_push_read_chunk() (Matthias Clasen).
@@ -1089,33 +1207,45 @@ version 1.2.2beta5 [March 26, 2002]
Changed "()" to "{}" in scripts/libpng.pc.in.
Revised makefiles to put png.h and pngconf.h only in $prefix/include/libpngNN
Revised makefiles to make symlink to libpng.so.NN in addition to libpngNN.so
-version 1.2.2beta6 [March 31, 2002]
-version 1.0.13beta1 [March 31, 2002]
+
+Version 1.2.2beta6 [March 31, 2002]
+
+Version 1.0.13beta1 [March 31, 2002]
Prevent png_zalloc() from trying to memset memory that it failed to acquire.
Add typecasts of PNG_MAX_UINT in pngset_cHRM_fixed() (Matt Holgate).
Ensure that the right function (user or default) is used to free the
png_struct after an error in png_create_read_struct_2().
-version 1.2.2rc1 [April 7, 2002]
-version 1.0.13rc1 [April 7, 2002]
+
+Version 1.2.2rc1 [April 7, 2002]
+
+Version 1.0.13rc1 [April 7, 2002]
Save the ebx register in pnggccrd.c (Sami Farin)
Add "mem_ptr = png_ptr->mem_ptr" in png_destroy_write_struct() (Paul Gardner).
Updated makefiles to put headers in include/libpng and remove old include/*.h.
-version 1.2.2 [April 15, 2002]
-version 1.0.13 [April 15, 2002]
+Version 1.2.2 [April 15, 2002]
+
+Version 1.0.13 [April 15, 2002]
Revised description of png_set_filter() in libpng.3/libpng.txt.
Revised makefile.netbsd and added makefile.neNNbsd and makefile.freebsd
-version 1.0.13patch01 [April 17, 2002]
-version 1.2.2patch01 [April 17, 2002]
- Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and makefile.sggcc
- Fixed VER -> PNGVER typo in makefile.macosx and added install-static to install
+
+Version 1.0.13patch01 [April 17, 2002]
+
+Version 1.2.2patch01 [April 17, 2002]
+ Changed ${PNGMAJ}.${PNGVER} bug to ${PNGVER} in makefile.sgi and
+ makefile.sggcc
+ Fixed VER -> PNGVER typo in makefile.macosx and added install-static to
+ install
Added install: target to makefile.32sunu and makefile.64sunu
-version 1.0.13patch03 [April 18, 2002]
-version 1.2.2patch03 [April 18, 2002]
+
+Version 1.0.13patch03 [April 18, 2002]
+
+Version 1.2.2patch03 [April 18, 2002]
Revised 15 makefiles to link libpng.a to libpngNN.a and the include libpng
subdirectory to libpngNN subdirectory without the full pathname.
Moved generation of libpng.pc from "install" to "all" in 15 makefiles.
-version 1.2.3rc1 [April 28, 2002]
+
+Version 1.2.3rc1 [April 28, 2002]
Added install-man target to 15 makefiles (Dimitri Papadopolous-Orfanos).
Added $(DESTDIR) feature to 24 makefiles (Tim Mooney)
Fixed bug with $prefix, should be $(prefix) in makefile.hpux.
@@ -1127,70 +1257,83 @@ version 1.2.3rc1 [April 28, 2002]
to put one in their application.
Restored png_zalloc() and png_zfree() prototypes to version 1.2.1 and
removed them from module definition files.
-version 1.2.3rc2 [May 1, 2002]
+
+Version 1.2.3rc2 [May 1, 2002]
Fixed bug in reporting number of channels in pngget.c and pngset.c,
that was introduced in version 1.2.2beta5.
Exported png_zalloc(), png_zfree(), png_default_read(), png_default_write(),
png_default_flush(), and png_push_fill_buffer() and included them in
module definition files.
Added "libpng.pc" dependency to the "install-shared" target in 15 makefiles.
-version 1.2.3rc3 [May 1, 2002]
+
+Version 1.2.3rc3 [May 1, 2002]
Revised prototype for png_default_flush()
Remove old libpng.pc and libpngNN.pc before installing new ones.
-version 1.2.3rc4 [May 2, 2002]
+
+Version 1.2.3rc4 [May 2, 2002]
Typos in *.def files (png_default_read|write -> png_default_read|write_data)
In makefiles, changed rm libpng.NN.pc to rm libpngNN.pc
- Added libpng-config and libpngNN-config and modified makefiles to install them.
+ Added libpng-config and libpngNN-config and modified makefiles to install
+ them.
Changed $(MANPATH) to $(DESTDIR)$(MANPATH) in makefiles
Added "Win32 DLL VB" configuration to projects/msvc/libpng.dsp
-version 1.2.3rc5 [May 11, 2002]
+
+Version 1.2.3rc5 [May 11, 2002]
Changed "error" and "message" in prototypes to "error_message" and
"warning_message" to avoid namespace conflict.
Revised 15 makefiles to build libpng-config from libpng-config-*.in
Once more restored png_zalloc and png_zfree to regular nonexported form.
Restored png_default_read|write_data, png_default_flush, png_read_fill_buffer
- to nonexported form, but with PNGAPI, and removed them from module def files.
-version 1.2.3rc6 [May 14, 2002]
+ to nonexported form, but with PNGAPI, and removed them from module def
+ files.
+
+Version 1.2.3rc6 [May 14, 2002]
Removed "PNGAPI" from png_zalloc() and png_zfree() in png.c
Changed "Gz" to "Gd" in projects/msvc/libpng.dsp and zlib.dsp.
Removed leftover libpng-config "sed" script from four makefiles.
Revised libpng-config creating script in 16 makefiles.
-version 1.2.3 [May 22, 2002]
+Version 1.2.3 [May 22, 2002]
Revised libpng-config target in makefile.cygwin.
Removed description of png_set_mem_fn() from documentation.
Revised makefile.freebsd.
Minor cosmetic changes to 15 makefiles, e.g., $(DI) = $(DESTDIR)/$(INCDIR).
Revised projects/msvc/README.txt
Changed -lpng to -lpngNN in LDFLAGS in several makefiles.
-version 1.2.4beta1 [May 24, 2002]
+
+Version 1.2.4beta1 [May 24, 2002]
Added libpng.pc and libpng-config to "all:" target in 16 makefiles.
Fixed bug in 16 makefiles: $(DESTDIR)/$(LIBPATH) to $(DESTDIR)$(LIBPATH)
Added missing "\" before closing double quote in makefile.gcmmx.
Plugged various memory leaks; added png_malloc_warn() and png_set_text_2()
functions.
-version 1.2.4beta2 [June 25, 2002]
+
+Version 1.2.4beta2 [June 25, 2002]
Plugged memory leak of png_ptr->current_text (Matt Holgate).
Check for buffer overflow before reading CRC in pngpread.c (Warwick Allison)
Added -soname to the loader flags in makefile.dec, makefile.sgi, and
makefile.sggcc.
Added "test-installed" target to makefile.linux, makefile.gcmmx,
makefile.sgi, and makefile.sggcc.
-version 1.2.4beta3 [June 28, 2002]
+
+Version 1.2.4beta3 [June 28, 2002]
Plugged memory leak of row_buf in pngtest.c when there is a png_error().
Detect buffer overflow in pngpread.c when IDAT is corrupted with extra data.
Added "test-installed" target to makefile.32sunu, makefile.64sunu,
makefile.beos, makefile.darwin, makefile.dec, makefile.macosx,
makefile.solaris, makefile.hpux, makefile.hpgcc, and makefile.so9.
-version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
+
+Version 1.2.4rc1 and 1.0.14rc1 [July 2, 2002]
Added "test-installed" target to makefile.cygwin and makefile.sco.
Revised pnggccrd.c to be able to back out version 1.0.x via PNG_1_0_X macro.
-version 1.2.4 and 1.0.14 [July 8, 2002]
+Version 1.2.4 and 1.0.14 [July 8, 2002]
Changed png_warning() to png_error() when width is too large to process.
-version 1.2.4patch01 [July 20, 2002]
+
+Version 1.2.4patch01 [July 20, 2002]
Revised makefile.cygwin to use DLL number 12 instead of 13.
-version 1.2.5beta1 [August 6, 2002]
+
+Version 1.2.5beta1 [August 6, 2002]
Added code to contrib/gregbook/readpng2.c to ignore unused chunks.
Replaced toucan.png in contrib/gregbook (it has been corrupt since 1.0.11)
Removed some stray *.o files from contrib/gregbook.
@@ -1199,36 +1342,43 @@ version 1.2.5beta1 [August 6, 2002]
Prevent png_ptr->pass from exceeding 7 in png_push_finish_row().
Updated makefile.hpgcc
Updated png.c and pnggccrd.c handling of return from png_mmx_support()
-version 1.2.5beta2 [August 15, 2002]
+
+Version 1.2.5beta2 [August 15, 2002]
Only issue png_warning() about "Too much data" in pngpread.c when avail_in
is nonzero.
Updated makefiles to install a separate libpng.so.3 with its own rpath.
-version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
+
+Version 1.2.5rc1 and 1.0.15rc1 [August 24, 2002]
Revised makefiles to not remove previous minor versions of shared libraries.
-version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
+
+Version 1.2.5rc2 and 1.0.15rc2 [September 16, 2002]
Revised 13 makefiles to remove "-lz" and "-L$(ZLIBLIB)", etc., from shared
library loader directive.
Added missing "$OBJSDLL" line to makefile.gcmmx.
Added missing "; fi" to makefile.32sunu.
-version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
+
+Version 1.2.5rc3 and 1.0.15rc3 [September 18, 2002]
Revised libpng-config script.
-version 1.2.5 and 1.0.15 [October 3, 2002]
+Version 1.2.5 and 1.0.15 [October 3, 2002]
Revised makefile.macosx, makefile.darwin, makefile.hpgcc, and makefile.hpux,
and makefile.aix.
Relocated two misplaced PNGAPI lines in pngtest.c
-version 1.2.6beta1 [October 22, 2002]
+
+Version 1.2.6beta1 [October 22, 2002]
Commented out warning about uninitialized mmx_support in pnggccrd.c.
Changed "IBMCPP__" flag to "__IBMCPP__" in pngconf.h.
Relocated two more misplaced PNGAPI lines in pngtest.c
Fixed memory overrun bug in png_do_read_filler() with 16-bit datastreams,
introduced in version 1.0.2.
Revised makefile.macosx, makefile.dec, makefile.aix, and makefile.32sunu.
-version 1.2.6beta2 [November 1, 2002]
+
+Version 1.2.6beta2 [November 1, 2002]
Added libpng-config "--ldopts" output.
Added "AR=ar" and "ARFLAGS=rc" and changed "ar rc" to "$(AR) $(ARFLAGS)"
in makefiles.
-version 1.2.6beta3 [July 18, 2004]
+
+Version 1.2.6beta3 [July 18, 2004]
Reverted makefile changes from version 1.2.6beta2 and some of the changes
from version 1.2.6beta1; these will be postponed until version 1.2.7.
Version 1.2.6 is going to be a simple bugfix release.
@@ -1281,7 +1431,8 @@ version 1.2.6beta3 [July 18, 2004]
Updated contrib/visupng/VisualPng.dsp (Cosmin).
Updated contrib/visupng/cexcept.h to version 2.0.0 (Cosmin).
Added a separate distribution with "configure" and supporting files (Junichi).
-version 1.2.6beta4 [July 28, 2004]
+
+Version 1.2.6beta4 [July 28, 2004]
Added user ability to change png_size_t via a PNG_SIZE_T macro.
Added png_sizeof() and png_convert_size() functions.
Added PNG_SIZE_MAX (maximum value of a png_size_t variable.
@@ -1301,11 +1452,13 @@ version 1.2.6beta4 [July 28, 2004]
Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
sequential read support.
Added some "#if PNG_WRITE_SUPPORTED" blocks.
- Removed some redundancy with #ifdef/#endif in png_malloc_default().
- Use png_malloc instead of png_zalloc to allocate the pallete.
-version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
- Fixed buffer overflow vulnerability in png_handle_tRNS()
- Fixed integer arithmetic overflow vulnerability in png_read_png().
+ Added #ifdef to remove some redundancy in png_malloc_default().
+ Use png_malloc instead of png_zalloc to allocate the palette.
+
+Version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
+ Fixed buffer overflow vulnerability (CVE-2004-0597) in png_handle_tRNS().
+ Fixed NULL dereference vulnerability (CVE-2004-0598) in png_handle_iCCP().
+ Fixed integer overflow vulnerability (CVE-2004-0599) in png_read_png().
Fixed some harmless bugs in png_handle_sBIT, etc, that would cause
duplicate chunk types to go undetected.
Fixed some timestamps in the -config version
@@ -1318,7 +1471,8 @@ version 1.0.16rc1 and 1.2.6rc1 [August 4, 2004]
Fixed wrong cast of returns from png_get_user_width|height_max().
Changed some "keep the compiler happy" from empty statements to returns,
Revised libpng.txt to remove 1.2.x stuff from the 1.0.x distribution
-version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
+
+Version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
Revised makefile.darwin and makefile.solaris. Removed makefile.macosx.
Revised pngtest's png_debug_malloc() to use png_malloc() instead of
png_malloc_default() which is not supposed to be exported.
@@ -1332,91 +1486,106 @@ version 1.0.16rc2 and 1.2.6rc2 [August 7, 2004]
Changed "HANDLE_CHUNK_*" to "PNG_HANDLE_CHUNK_*" (Cosmin)
Added "-@/bin/rm -f $(DL)/$(LIBNAME).so.$(PNGMAJ)" to 15 *NIX makefiles.
Added code to update the row_info->colortype in png_do_read_filler() (MSB).
-version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
+
+Version 1.0.16rc3 and 1.2.6rc3 [August 9, 2004]
Eliminated use of "abs()" in testing cHRM and gAMA values, to avoid
trouble with some 64-bit compilers. Created PNG_OUT_OF_RANGE() macro.
Revised documentation of png_set_keep_unknown_chunks().
Check handle_as_unknown status in pngpread.c, as in pngread.c previously.
Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_INTERNAL section of png.h
Added "rim" definitions for CONST4 and CONST6 in pnggccrd.c
-version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
+
+Version 1.0.16rc4 and 1.2.6rc4 [August 10, 2004]
Fixed mistake in pngtest.c introduced in 1.2.6rc2 (declaration of
"pinfo" was out of place).
-version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
+
+Version 1.0.16rc5 and 1.2.6rc5 [August 10, 2004]
Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
- section of png.h where they were inadvertently placed in version rc3.
+ section of png.h where they were inadvertently placed in version rc3.
-version 1.2.6 and 1.0.16 [August 15, 2004]
+Version 1.2.6 and 1.0.16 [August 15, 2004]
Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
-version 1.2.7beta1 [August 26, 2004]
+
+Version 1.2.7beta1 [August 26, 2004]
Removed unused pngasmrd.h file.
Removed references to uu.net for archived files. Added references to
PNG Spec (second edition) and the PNG ISO/IEC Standard.
Added "test-dd" target in 15 makefiles, to run pngtest in DESTDIR.
Fixed bug with "optimized window size" in the IDAT datastream, that
causes libpng to write PNG files with incorrect zlib header bytes.
-version 1.2.7beta2 [August 28, 2004]
+
+Version 1.2.7beta2 [August 28, 2004]
Fixed bug with sCAL chunk and big-endian machines (David Munro).
Undid new code added in 1.2.6rc2 to update the color_type in
png_set_filler().
Added png_set_add_alpha() that updates color type.
-version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
+
+Version 1.0.17rc1 and 1.2.7rc1 [September 4, 2004]
Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
-version 1.2.7 and 1.0.17 [September 12, 2004]
+Version 1.2.7 and 1.0.17 [September 12, 2004]
Added makefile.hp64
Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
-version 1.2.8beta1 [November 1, 2004]
+
+Version 1.2.8beta1 [November 1, 2004]
Fixed bug in png_text_compress() that would fail to complete a large block.
Fixed bug, introduced in libpng-1.2.7, that overruns a buffer during
strip alpha operation in png_do_strip_filler().
Added PNG_1_2_X definition in pngconf.h
- Comment out with #ifdef/#endif png_info_init in png.c and png_read_init
- in pngread.c (as of 1.3.0)
-version 1.2.8beta2 [November 2, 2004]
+ Use #ifdef to comment out png_info_init in png.c and png_read_init in
+ pngread.c (as of 1.3.0)
+
+Version 1.2.8beta2 [November 2, 2004]
Reduce color_type to a nonalpha type after strip alpha operation in
png_do_strip_filler().
-version 1.2.8beta3 [November 3, 2004]
+
+Version 1.2.8beta3 [November 3, 2004]
Revised definitions of PNG_MAX_UINT_32, PNG_MAX_SIZE, and PNG_MAXSUM
-version 1.2.8beta4 [November 12, 2004]
+
+Version 1.2.8beta4 [November 12, 2004]
Fixed (again) definition of PNG_LIBPNG_VER_DLLNUM in png.h (Cosmin).
Added PNG_LIBPNG_BUILD_PRIVATE in png.h (Cosmin).
Set png_ptr->zstream.data_type to Z_BINARY, to avoid unnecessary detection
of data type in deflate (Cosmin).
Deprecated but continue to support SPECIALBUILD and PRIVATEBUILD in favor of
PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
-version 1.2.8beta5 [November 20, 2004]
+
+Version 1.2.8beta5 [November 20, 2004]
Use png_ptr->flags instead of png_ptr->transformations to pass
PNG_STRIP_ALPHA info to png_do_strip_filler(), to preserve ABI
compatibility.
Revised handling of SPECIALBUILD, PRIVATEBUILD,
PNG_LIBPNG_BUILD_SPECIAL_STRING and PNG_LIBPNG_BUILD_PRIVATE_STRING.
-version 1.2.8rc1 [November 24, 2004]
+
+Version 1.2.8rc1 [November 24, 2004]
Moved handling of BUILD macros from pngconf.h to png.h
Added definition of PNG_LIBPNG_BASE_TYPE in png.h, inadvertently
omitted from beta5.
Revised scripts/pngw32.rc
Despammed mailing addresses by masking "@" with "at".
Inadvertently installed a supposedly faster test version of pngrutil.c
-version 1.2.8rc2 [November 26, 2004]
+
+Version 1.2.8rc2 [November 26, 2004]
Added two missing "\" in png.h
Change tests in pngread.c and pngpread.c to
if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
png_do_read_transformations(png_ptr);
-version 1.2.8rc3 [November 28, 2004]
+
+Version 1.2.8rc3 [November 28, 2004]
Reverted pngrutil.c to version libpng-1.2.8beta5.
Added scripts/makefile.elf with supporting code in pngconf.h for symbol
versioning (John Bowler).
-version 1.2.8rc4 [November 29, 2004]
+
+Version 1.2.8rc4 [November 29, 2004]
Added projects/visualc7 (Simon-pierre).
-version 1.2.8rc5 [November 29, 2004]
+
+Version 1.2.8rc5 [November 29, 2004]
Fixed new typo in scripts/pngw32.rc
-version 1.2.8 [December 3, 2004]
+Version 1.2.8 [December 3, 2004]
Removed projects/visualc7, added projects/visualc71.
-version 1.2.9beta1 [February 21, 2006]
-
+Version 1.2.9beta1 [February 21, 2006]
Initialized some structure members in pngwutil.c to avoid gcc-4.0.0 complaints
Revised man page and libpng.txt to make it clear that one should not call
png_read_end or png_write_end after png_read_png or png_write_png.
@@ -1438,8 +1607,7 @@ version 1.2.9beta1 [February 21, 2006]
Fixed scripts/makefile.cygwin (Christian Biesinger, Cosmin).
Default iTXt support was inadvertently enabled.
-version 1.2.9beta2 [February 21, 2006]
-
+Version 1.2.9beta2 [February 21, 2006]
Check for png_rgb_to_gray and png_gray_to_rgb read transformations before
checking for png_read_dither in pngrtran.c
Revised checking of chromaticity limits to accommodate extended RGB
@@ -1452,8 +1620,7 @@ version 1.2.9beta2 [February 21, 2006]
Eliminated distributions without the "configure" script.
Updated INSTALL instructions.
-version 1.2.9beta3 [February 24, 2006]
-
+Version 1.2.9beta3 [February 24, 2006]
Fixed CRCRLF line endings in contrib/visupng/VisualPng.dsp
Made libpng.pc respect EXEC_PREFIX (D. P. Kreil, J. Bowler)
Removed reference to pngasmrd.h from Makefile.am
@@ -1462,8 +1629,7 @@ version 1.2.9beta3 [February 24, 2006]
Renamed ANNOUNCE to NEWS.
Created AUTHORS file.
-version 1.2.9beta4 [March 3, 2006]
-
+Version 1.2.9beta4 [March 3, 2006]
Changed definition of PKGCONFIG from $prefix/lib to $libdir in configure.ac
Reverted to filenames LICENSE and ANNOUNCE; removed AUTHORS and COPYING.
Removed newline from the end of some error and warning messages.
@@ -1474,17 +1640,17 @@ version 1.2.9beta4 [March 3, 2006]
Added "OS2" to list of systems that don't need underscores, in pnggccrd.c
Removed libpng version and date from *.c files.
-version 1.2.9beta5 [March 4, 2006]
+Version 1.2.9beta5 [March 4, 2006]
Removed trailing blanks from source files.
Put version and date of latest change in each source file, and changed
copyright year accordingly.
- More cleanup of configure.ac, Makefile.ac, and associated scripts.
+ More cleanup of configure.ac, Makefile.am, and associated scripts.
Restored scripts/makefile.elf which was inadvertently deleted.
-version 1.2.9beta6 [March 6, 2006]
+Version 1.2.9beta6 [March 6, 2006]
Fixed typo (RELEASE) in configuration files.
-version 1.2.9beta7 [March 7, 2006]
+Version 1.2.9beta7 [March 7, 2006]
Removed libpng.vers and libpng.sym from libpng12_la_SOURCES in Makefile.am
Fixed inconsistent #ifdef's around png_sig_bytes() and png_set_sCAL_s()
in png.h.
@@ -1492,7 +1658,7 @@ version 1.2.9beta7 [March 7, 2006]
Made cosmetic changes to some makefiles, adding LN_SF and other macros.
Made some makefiles accept "exec_prefix".
-version 1.2.9beta8 [March 9, 2006]
+Version 1.2.9beta8 [March 9, 2006]
Fixed some "#if defined (..." which should be "#if defined(..."
Bug introduced in libpng-1.2.8.
Fixed inconsistency in definition of png_default_read_data()
@@ -1503,82 +1669,82 @@ version 1.2.9beta8 [March 9, 2006]
Added png_set_expand_gray_1_2_4_to_8() and deprecated
png_set_gray_1_2_4_to_8() which also expands tRNS to alpha.
-version 1.2.9beta9 [March 10, 2006]
+Version 1.2.9beta9 [March 10, 2006]
Include "config.h" in pngconf.h when available.
Added some checks for NULL png_ptr or NULL info_ptr (timeless)
-version 1.2.9beta10 [March 20, 2006]
+Version 1.2.9beta10 [March 20, 2006]
Removed extra CR from contrib/visualpng/VisualPng.dsw (Cosmin)
Made pnggccrd.c PIC-compliant (Christian Aichinger).
Added makefile.mingw (Wolfgang Glas).
Revised pngconf.h MMX checking.
-version 1.2.9beta11 [March 22, 2006]
+Version 1.2.9beta11 [March 22, 2006]
Fixed out-of-order declaration in pngwrite.c that was introduced in beta9
Simplified some makefiles by using LIBSO, LIBSOMAJ, and LIBSOVER macros.
-version 1.2.9rc1 [March 31, 2006]
+Version 1.2.9rc1 [March 31, 2006]
Defined PNG_USER_PRIVATEBUILD when including "pngusr.h" (Cosmin).
Removed nonsensical assertion check from pngtest.c (Cosmin).
-version 1.2.9 [April 14, 2006]
+Version 1.2.9 [April 14, 2006]
Revised makefile.beos and added "none" selector in ltmain.sh
-version 1.2.10beta1 [April 15, 2006]
+Version 1.2.10beta1 [April 15, 2006]
Renamed "config.h" to "png_conf.h" and revised Makefile.am to add
-DPNG_BUILDING_LIBPNG to compile directive, and modified pngconf.h
to include png_conf.h only when PNG_BUILDING_LIBPNG is defined.
-version 1.2.10beta2 [April 15, 2006]
+Version 1.2.10beta2 [April 15, 2006]
Manually updated Makefile.in and configure. Changed png_conf.h.in
back to config.h.
-version 1.2.10beta3 [April 15, 2006]
+Version 1.2.10beta3 [April 15, 2006]
Change png_conf.h back to config.h in pngconf.h.
-version 1.2.10beta4 [April 16, 2006]
+Version 1.2.10beta4 [April 16, 2006]
Change PNG_BUILDING_LIBPNG to PNG_CONFIGURE_LIBPNG in config/Makefile*.
-version 1.2.10beta5 [April 16, 2006]
+Version 1.2.10beta5 [April 16, 2006]
Added a configure check for compiling assembler code in pnggccrd.c
-version 1.2.10beta6 [April 17, 2006]
+Version 1.2.10beta6 [April 17, 2006]
Revised the configure check for pnggccrd.c
Moved -DPNG_CONFIGURE_LIBPNG into @LIBPNG_DEFINES@
Added @LIBPNG_DEFINES@ to arguments when building libpng.sym
-version 1.2.10beta7 [April 18, 2006]
+Version 1.2.10beta7 [April 18, 2006]
Change "exec_prefix=$prefix" to "exec_prefix=$(prefix)" in makefiles.
-version 1.2.10rc1 [April 19, 2006]
+Version 1.2.10rc1 [April 19, 2006]
Ensure pngconf.h doesn't define both PNG_USE_PNGGCCRD and PNG_USE_PNGVCRD
Fixed "LN_FS" typo in makefile.sco and makefile.solaris.
-version 1.2.10rc2 [April 20, 2006]
+Version 1.2.10rc2 [April 20, 2006]
Added a backslash between -DPNG_CONFIGURE_LIBPNG and -DPNG_NO_ASSEMBLER_CODE
in configure.ac and configure
Made the configure warning about versioned symbols less arrogant.
-version 1.2.10rc3 [April 21, 2006]
+Version 1.2.10rc3 [April 21, 2006]
Added a note in libpng.txt that png_set_sig_bytes(8) can be used when
writing an embedded PNG without the 8-byte signature.
Revised makefiles and configure to avoid making links to libpng.so.*
-version 1.2.10 [April 23, 2006]
+Version 1.2.10 [April 23, 2006]
Reverted configure to "rc2" state.
-version 1.2.11beta1 [May 31, 2006]
+Version 1.2.11beta1 [May 31, 2006]
scripts/libpng.pc.in contained "configure" style version info and would
not work with makefiles.
The shared-library makefiles were linking to libpng.so.0 instead of
libpng.so.3 compatibility as the library.
-version 1.2.11beta2 [June 2, 2006]
+Version 1.2.11beta2 [June 2, 2006]
Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
buffer overflow.
Fixed bug in example.c (png_set_palette_rgb -> png_set_palette_to_rgb)
-version 1.2.11beta3 [June 5, 2006]
+Version 1.2.11beta3 [June 5, 2006]
Prepended "#! /bin/sh" to ltmail.sh and contrib/pngminus/*.sh (Cosmin).
Removed the accidental leftover Makefile.in~ (Cosmin).
Avoided potential buffer overflow and optimized buffer in
@@ -1586,116 +1752,116 @@ version 1.2.11beta3 [June 5, 2006]
Removed the include directories and libraries from CFLAGS and LDFLAGS
in scripts/makefile.gcc (Nelson A. de Oliveira, Cosmin).
-version 1.2.11beta4 [June 6, 2006]
+Version 1.2.11beta4 [June 6, 2006]
Allow zero-length IDAT chunks after the entire zlib datastream, but not
after another intervening chunk type.
-version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
+Version 1.0.19rc1, 1.2.11rc1 [June 13, 2006]
Deleted extraneous square brackets from [config.h] in configure.ac
-version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
+Version 1.0.19rc2, 1.2.11rc2 [June 14, 2006]
Added prototypes for PNG_INCH_CONVERSIONS functions to png.h
Revised INSTALL and autogen.sh
Fixed typo in several makefiles (-W1 should be -Wl)
Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
-version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
+Version 1.0.19rc3, 1.2.11rc3 [June 15, 2006]
Removed the new typedefs for 64-bit systems (delay until version 1.4.0)
Added one zero element to png_gamma_shift[] array in pngrtran.c to avoid
reading out of bounds.
-version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
+Version 1.0.19rc4, 1.2.11rc4 [June 15, 2006]
Really removed the new typedefs for 64-bit systems.
-version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
+Version 1.0.19rc5, 1.2.11rc5 [June 22, 2006]
Removed png_sig_bytes entry from scripts/pngw32.def
-version 1.0.19, 1.2.11 [June 26, 2006]
+Version 1.0.19, 1.2.11 [June 26, 2006]
None.
-version 1.0.20, 1.2.12 [June 27, 2006]
+Version 1.0.20, 1.2.12 [June 27, 2006]
Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
buffer overflow.
-version 1.2.13beta1 [October 2, 2006]
+Version 1.2.13beta1 [October 2, 2006]
Removed AC_FUNC_MALLOC from configure.ac
Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
Change "logical" to "bitwise" throughout documentation.
- Detect and fix attempt to write wrong iCCP profile length.
+ Detect and fix attempt to write wrong iCCP profile length (CVE-2006-7244)
-version 1.0.21, 1.2.13 [November 14, 2006]
+Version 1.0.21, 1.2.13 [November 14, 2006]
Fix potential buffer overflow in sPLT chunk handler.
Fix Makefile.am to not try to link to noexistent files.
Check all exported functions for NULL png_ptr.
-version 1.2.14beta1 [November 17, 2006]
+Version 1.2.14beta1 [November 17, 2006]
Relocated three misplaced tests for NULL png_ptr.
Built Makefile.in with automake-1.9.6 instead of 1.9.2.
Build configure with autoconf-2.60 instead of 2.59
-version 1.2.14beta2 [November 17, 2006]
+Version 1.2.14beta2 [November 17, 2006]
Added some typecasts in png_zalloc().
-version 1.2.14rc1 [November 20, 2006]
+Version 1.2.14rc1 [November 20, 2006]
Changed "strtod" to "png_strtod" in pngrutil.c
-version 1.0.22, 1.2.14 [November 27, 2006]
+Version 1.0.22, 1.2.14 [November 27, 2006]
Added missing "$(srcdir)" in Makefile.am and Makefile.in
-version 1.2.15beta1 [December 3, 2006]
+Version 1.2.15beta1 [December 3, 2006]
Generated configure with autoconf-2.61 instead of 2.60
Revised configure.ac to update libpng.pc and libpng-config.
-version 1.2.15beta2 [December 3, 2006]
+Version 1.2.15beta2 [December 3, 2006]
Always export MMX asm functions, just stubs if not building pnggccrd.c
-version 1.2.15beta3 [December 4, 2006]
+Version 1.2.15beta3 [December 4, 2006]
Add "png_bytep" typecast to profile while calculating length in pngwutil.c
-version 1.2.15beta4 [December 7, 2006]
+Version 1.2.15beta4 [December 7, 2006]
Added scripts/CMakeLists.txt
Changed PNG_NO_ASSEMBLER_CODE to PNG_NO_MMX_CODE in scripts, like 1.4.0beta
-version 1.2.15beta5 [December 7, 2006]
+Version 1.2.15beta5 [December 7, 2006]
Changed some instances of PNG_ASSEMBLER_* to PNG_MMX_* in pnggccrd.c
Revised scripts/CMakeLists.txt
-version 1.2.15beta6 [December 13, 2006]
+Version 1.2.15beta6 [December 13, 2006]
Revised scripts/CMakeLists.txt and configure.ac
-version 1.2.15rc1 [December 18, 2006]
+Version 1.2.15rc1 [December 18, 2006]
Revised scripts/CMakeLists.txt
-version 1.2.15rc2 [December 21, 2006]
+Version 1.2.15rc2 [December 21, 2006]
Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
Added scripts/makefile.nommx
-version 1.2.15rc3 [December 25, 2006]
+Version 1.2.15rc3 [December 25, 2006]
Fixed shared library numbering error that was introduced in 1.2.15beta6.
-version 1.2.15rc4 [December 27, 2006]
+Version 1.2.15rc4 [December 27, 2006]
Fixed handling of rgb_to_gray when png_ptr->color.gray isn't set.
-version 1.2.15rc5 [December 31, 2006]
+Version 1.2.15rc5 [December 31, 2006]
Revised handling of rgb_to_gray.
-version 1.0.23, 1.2.15 [January 5, 2007]
+Version 1.2.15 [January 5, 2007]
Added some (unsigned long) typecasts in pngtest.c to avoid printing errors.
-version 1.2.16beta1 [January 6, 2007]
+Version 1.2.16beta1 [January 6, 2007]
Fix bugs in makefile.nommx
-version 1.2.16beta2 [January 16, 2007]
+Version 1.2.16beta2 [January 16, 2007]
Revised scripts/CMakeLists.txt
-version 1.0.24, 1.2.16 [January 31, 2007]
+Version 1.2.16 [January 31, 2007]
No changes.
-version 1.2.17beta1 [March 6, 2007]
+Version 1.2.17beta1 [March 6, 2007]
Revised scripts/CMakeLists.txt to install both shared and static libraries.
Deleted a redundant line from pngset.c.
-version 1.2.17beta2 [April 26, 2007]
+Version 1.2.17beta2 [April 26, 2007]
Relocated misplaced test for png_ptr == NULL in pngpread.c
Change "==" to "&" for testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN
flags.
@@ -1704,10 +1870,10 @@ version 1.2.17beta2 [April 26, 2007]
Added "const" to some array declarations.
Mention examples of libpng usage in the libpng*.txt and libpng.3 documents.
-version 1.2.17rc1 [May 4, 2007]
+Version 1.2.17rc1 [May 4, 2007]
No changes.
-version 1.2.17rc2 [May 8, 2007]
+Version 1.2.17rc2 [May 8, 2007]
Moved several PNG_HAVE_* macros out of PNG_INTERNAL because applications
calling set_unknown_chunk_location() need them.
Changed transformation flag from PNG_EXPAND_tRNS to PNG_EXPAND in
@@ -1716,693 +1882,445 @@ version 1.2.17rc2 [May 8, 2007]
can be free'ed in case of error. Revised unknown chunk handling in
pngrutil.c and pngpread.c to use this structure.
-version 1.2.17rc3 [May 8, 2007]
+Version 1.2.17rc3 [May 8, 2007]
Revised symbol-handling in configure script.
-version 1.2.17rc4 [May 10, 2007]
+Version 1.2.17rc4 [May 10, 2007]
Revised unknown chunk handling to avoid storing unknown critical chunks.
-version 1.0.25 [May 15, 2007]
-version 1.2.17 [May 15, 2007]
+Version 1.0.25 [May 15, 2007]
+Version 1.2.17 [May 15, 2007]
Added "png_ptr->num_trans=0" before error return in png_handle_tRNS,
to eliminate a vulnerability (CVE-2007-2445, CERT VU#684664)
-version 1.0.26 [May 15, 2007]
-version 1.2.18 [May 15, 2007]
+Version 1.0.26 [May 15, 2007]
+Version 1.2.18 [May 15, 2007]
Reverted the libpng-1.2.17rc3 change to symbol-handling in configure script
-version 1.2.19beta1 [May 18, 2007]
+Version 1.2.19beta1 [May 18, 2007]
Changed "const static" to "static PNG_CONST" everywhere, mostly undoing
change of libpng-1.2.17beta2. Changed other "const" to "PNG_CONST"
Changed some handling of unused parameters, to avoid compiler warnings.
"if (unused == NULL) return;" becomes "unused = unused".
-version 1.2.19beta2 [May 18, 2007]
+Version 1.2.19beta2 [May 18, 2007]
Only use the valid bits of tRNS value in png_do_expand() (Brian Cartier)
-version 1.2.19beta3 [May 19, 2007]
+Version 1.2.19beta3 [May 19, 2007]
Add some "png_byte" typecasts in png_check_keyword() and write new_key
instead of key in zTXt chunk (Kevin Ryde).
-version 1.2.19beta4 [May 21, 2007]
+Version 1.2.19beta4 [May 21, 2007]
Add png_snprintf() function and use it in place of sprint() for improved
defense against buffer overflows.
-version 1.2.19beta5 [May 21, 2007]
+Version 1.2.19beta5 [May 21, 2007]
Fixed png_handle_tRNS() to only use the valid bits of tRNS value.
Changed handling of more unused parameters, to avoid compiler warnings.
Removed some PNG_CONST in pngwutil.c to avoid compiler warnings.
-version 1.2.19beta6 [May 22, 2007]
+Version 1.2.19beta6 [May 22, 2007]
Added some #ifdef PNG_MMX_CODE_SUPPORTED where needed in pngvcrd.c
Added a special "_MSC_VER" case that defines png_snprintf to _snprintf
-version 1.2.19beta7 [May 22, 2007]
+Version 1.2.19beta7 [May 22, 2007]
Squelched png_squelch_warnings() in pnggccrd.c and added
- an #ifdef PNG_MMX_CODE_SUPPORTED/#endif block around the declarations
- that caused the warnings that png_squelch_warnings was squelching.
+ an #ifdef PNG_MMX_CODE_SUPPORTED block around the declarations that caused
+ the warnings that png_squelch_warnings was squelching.
-version 1.2.19beta8 [May 22, 2007]
+Version 1.2.19beta8 [May 22, 2007]
Removed __MMX__ from test in pngconf.h.
-version 1.2.19beta9 [May 23, 2007]
+Version 1.2.19beta9 [May 23, 2007]
Made png_squelch_warnings() available via PNG_SQUELCH_WARNINGS macro.
Revised png_squelch_warnings() so it might work.
Updated makefile.sgcc and makefile.solaris; added makefile.solaris-x86.
-version 1.2.19beta10 [May 24, 2007]
+Version 1.2.19beta10 [May 24, 2007]
Resquelched png_squelch_warnings(), use "__attribute__((used))" instead.
-version 1.2.19beta11 [May 28, 2007]
- Return 0 from png_get_sPLT() and png_get_unknown_chunks() if png_ptr is NULL;
- changed three remaining instances of png_strcpy() to png_strncpy() (David
- Hill).
- Make test for NULL row_buf at the beginning of png_do_read_transformations
- unconditional.
-
-version 1.2.19beta12 [May 28, 2007]
- Revised pnggccrd.c.
-
-version 1.2.19beta13 [June 14, 2007]
- Prefer PNG_USE_PNGVCRD when _MSC_VER is defined in pngconf.h
-
-version 1.2.19beta14 [June 16, 2007]
- Fix bug with handling of 16-bit transparency, introduced in 1.2.19beta2
-
-version 1.2.19beta15 [June 17, 2007]
- Revised pnggccrd.c.
-
-version 1.2.19beta16 [June 18, 2007]
- Revised pnggccrd.c again.
- Updated contrib/gregbook.
- Changed '#include "pnggccrd.c"' to 'include "$srcdir/pnggccrd.c"'
- in configure.ac
-
-version 1.2.19beta17 [June 19, 2007]
- Revised many of the makefiles, to set -DPNG_NO_MMX_CODE where needed
- and to not use -O3 unless -DPNG_NO_MMX_CODE is also set.
-
-version 1.2.19beta18 [June 23, 2007]
- Replaced some C++ style comments with C style comments in pnggccrd.c.
- Copied optimized C code from pnggccrd.c to pngrutil.c, removed dependency
- on pnggccrd.o from many makefiles.
- Added sl and dylib to list of extensions be installed by Makefile.am
-
-version 1.2.19beta19 [June 28, 2007]
- Fixed testing PNG_RGB_TO_GRAY_ERR & PNG_RGB_TO_GRAY_WARN in pngrtran.c
- More cleanup of pnggccrd.c and pngvcrd.c
-
-version 1.2.19beta20 [June 29, 2007]
- Rebuilt Makefile.in and configure using libtool-1.5.24.
- Fixed typo in pnggccrd.c
-
-version 1.2.19beta21 [June 30, 2007]
- More revision of pnggccrd.c
- Added "test" target to Makefile.in and Makefile.am
-
-version 1.2.19beta22 [July 3, 2007]
- Added info about pngrutil/pnggccrd/pngvcrd to png_get_header_version()
- Fix type definition of dummy_value_a, b in pnggccrd.c
-
-version 1.2.19beta23 [July 10, 2007]
- Revert change to type definition of dummy_value_a, b in pnggccrd.c
- Make sure __PIC__ is defined in pnggccrd.c when PIC is defined.
- Require gcc-4.1 or better to use PNG_HAVE_MMX_FILTER_ROW on x86_64 platforms
-
-version 1.2.19beta24 [July 14, 2007]
- Added PNG_NO_READ_FILTER, PNG_NO_WRITE_FILTER, PNG_NO_WARNING macros.
- Added contrib/pngminim to demonstrate building minimal encoder and decoder
-
-version 1.2.19beta25 [July 15, 2007]
- Removed the new PNG_NO_READ_FILTER macro since it would make the library
- unable to read valid PNG files, and filtering is at the heart of the
- PNG format.
-
-version 1.2.19beta26 [July 16, 2007]
- Changed "png_free(str)" to "png_free(png_ptr,str)" in pngrutil.c WinCE
- code (Yves Piguet). This bug was introduced in libpng-1.2.14.
- Updated scripts/CMakeLists.txt
- Relocated a misplaced #endif in pnggccrd.c
-
-version 1.2.19beta27 [July 17, 2007]
- Fixed incorrect stride and number of bytes copied (was 4 instead of
- 6 bytes) in the cleanup loop of pnggccrd.c and pngvcrd.c for handling
- the end of 48-bit interlaced rows (Glenn R-P).
-
-version 1.2.19beta28 [July 19, 2007]
- Removed requirement for gcc-4.1 or better to use PNG_HAVE_MMX_FILTER_ROW
- on x86_64 platforms
- Added png_warning() in pngrutil.c for short iCCP, iTXt, sPLT, or zTXT chunks.
- Revised pngtest.c so warnings are displayed regardless of PNG_NO_STDIO.
-
-version 1.2.19beta29 [July 20, 2007]
- Fix typo in pnggccrd.c (%%eax should be %%ax in secondloop48)
-
-version 1.2.19beta30 [July 26, 2007]
- Revised pnggccrd.c
-
-version 1.2.19beta31 [July 27, 2007]
- Fix typos in pnggccrd.c
-
-version 1.0.27rc1 and 1.2.19rc1 [July 31, 2007]
- Disable PNG_MMX_CODE_SUPPORTED when PNG_ASSEMBLER_CODE_SUPPORTED is off.
- Enable PNG_MMX_READ_FILTER_* by default, except when gcc-3.x is being
- used (they were inadvertently disabled in libpng-1.2.19beta23).
- Fix some debugging statements in pnggccrd.c and pngrutil.c
- Added information about disabling the MMX code in libpng documentation.
-
-version 1.0.27rc2 and 1.2.19rc2 [August 4, 2007]
- Removed some "#if 0" blocks.
- Made a global struct local in pngvcrd.c to make it thread safe.
- Issue a png_error() if application attempts to transform a row tht
- has not been initialized.
-
-version 1.0.27rc3 and 1.2.19rc3 [August 9, 2007]
- Slightly revised pngvcrd.c
-
-version 1.0.27rc4 and 1.2.19rc4 [August 9, 2007]
- Revised pnggccrd.c debugging change of rc1, which was broken.
- Revised scripts/CMakeLists.txt
- Change default to PNG_NO_GLOBAL_ARRAYS for MSVC.
- Turn off PNG_FLAG_ROW_INIT flag when setting transforms that expand pixels.
-
-version 1.0.27rc5 and 1.2.19rc5 [August 10, 2007]
- Fix typo (missing '"') in pnggccrd.c
- Revise handling of png_strtod in recent versions of WINCE
-
-version 1.0.27rc6 and 1.2.19rc6 [August 15, 2007]
- Fix typo (missing ',') in contrib/gregbook/readpng2.c
- Undid row initialization error exit added to rc2 and rc4.
-
-version 1.0.27 and 1.2.19 [August 18, 2007]
- Conditionally restored row initialization error exit.
-
-version 1.2.20beta01 [August 19, 2007]
- Fixed problem with compiling pnggccrd.c on Intel-Apple platforms.
- Changed png_malloc() to png_malloc_warn() in png_set_sPLT().
- Added PNG_NO_ERROR_TEXT feature, with demo in contrib/pngminim
- Removed define PNG_WARN_UNINITIALIZED_ROW 1 /* 0: warning; 1: error */
- because it caused some trouble.
-
-version 1.2.20beta02 [August 20, 2007]
- Avoid compiling pnggccrd.c on Intel-Apple platforms.
-
-version 1.2.20beta03 [August 20, 2007]
- Added "/D PNG_NO_MMX_CODE" to the non-mmx builds of projects/visualc6
- and visualc71.
-
-version 1.2.20beta04 [August 21, 2007]
- Revised pngvcrd.c for improved efficiency (Steve Snyder).
-
-version 1.2.20rc1 [August 23, 2007]
- Revised pngconf.h to set PNG_NO_MMX_CODE for gcc-3.x compilers.
-
-version 1.2.20rc2 [August 27, 2007]
- Revised scripts/CMakeLists.txt
- Revised #ifdefs to ensure one and only one of pnggccrd.c, pngvcrd.c,
- or part of pngrutil.c is selected.
-
-version 1.2.20rc3 [August 30, 2007]
- Remove a little more code in pngwutil.c when PNG_NO_WRITE_FILTER is selected.
- Added /D _CRT_SECURE_NO_WARNINGS to visual6c and visualc71 projects.
- Compile png_mmx_support() in png.c even when PNG_NO_MMX_CODE is defined.
- Restored a "superfluous" #ifdef that was removed from 1.2.20rc2 pnggccrd.c,
- breaking the png_mmx_support() function.
-
-version 1.2.20rc4 [September 1, 2007]
- Removed Intel contributions (MMX, Optimized C).
-
-version 1.2.20rc5 [September 2, 2007]
- Restored configure and Makefile.in to rc3 and put a snippet of code in
- pnggccrd.c, to ensure configure makes the same PNG_NO_MMX_CODE selection
-
-version 1.2.20rc6 [September 2, 2007]
- Fixed bugs in scripts/CMakeLists.txt
- Removed pngvcrd.c references from msvc projects.
-
-version 1.0.28 and 1.2.20 [September 8, 2007]
- Removed "(NO READ SUPPORT)" from png_get_header_version() string.
-
-version 1.2.21beta1 [September 14, 2007]
- Fixed various mistakes reported by George Cook and Jeff Phillips:
- logical vs bitwise NOT in pngrtran.c, bug introduced in 1.2.19rc2
- 16-bit cheap transparency expansion, bug introduced in 1.2.19beta2
- errors with sizeof(unknown_chunk.name), bugs introduced in 1.2.19beta11
- <= compare with unsigned var in pngset.c, should be ==.
-
-version 1.2.21beta2 [September 18, 2007]
- Removed some extraneous typecasts.
-
-version 1.2.21rc1 [September 25, 2007]
- Fixed potential out-of-bounds reads in png_handle_pCAL() and
- png_handle_ztXt() ("flayer" results reported by Tavis Ormandy).
-
-version 1.2.21rc2 [September 26, 2007]
- Fixed potential out-of-bounds reads in png_handle_sCAL(),
- png_handle_iTXt(), and png_push_read_tEXt().
- Remove some PNG_CONST declarations from pngwutil.c to avoid compiler warnings
- Revised makefiles to update paths in libpng.pc properly.
-
-version 1.2.21rc3 [September 27, 2007]
- Revised makefiles to update "Libs" in libpng.pc properly.
-
-version 1.0.29 and 1.2.21rc3 [October 4, 2007]
- No changes.
-
-version 1.2.22beta1 [October 4, 2007]
- Again, fixed logical vs bitwise NOT in pngrtran.c, bug introduced
- in 1.2.19rc2
-
-version 1.2.22beta2 [October 5, 2007]
- Fixed string length error in pngset.c (caused crashes while decoding iCCP)
- Add terminating NULL after each instance of png_strncpy().
-
-version 1.2.22beta3 [October 6, 2007]
- Fix two off-by-one terminating NULL after png_strncpy().
-
-version 1.2.22beta4 [October 7, 2007]
- Changed some 0 to '\0'.
-
-version 1.0.30rc1 and 1.2.22rc1 [October 8, 2007]
- No changes.
-
-version 1.0.30 and 1.2.22 [October 13, 2007]
- No changes.
-
-version 1.2.23beta01 [October 15, 2007]
- Reduced number of invocations of png_strlen() in pngset.c.
- Changed [azAZ09_] to [_abcde...89] in Makefile.am for better localization.
-
-version 1.2.23beta02 [October 16, 2007]
- Eliminated png_strncpy() and png_strcpy() (Pierre Poissinger)
- Changed $AN to $(AN) in Makefile.am.
-
-version 1.2.23beta03 [October 16, 2007]
- Fixed off-by-one error in pngset.c
- Restore statement to set last character of buffer to \0 in pngerror.c
-
-version 1.2.23beta04 [October 23, 2007]
- Reject attempt to set all-zero cHRM values.
-
-version 1.2.23beta05 [October 26, 2007]
- Add missing quotes in projects/visualc6, lost in version 1.2.20rc3
-
-version 1.2.23rc01 [November 2, 2007]
- No changes.
-
-version 1.2.23 [November 6, 2007]
- No changes.
-
-version 1.2.24beta01 [November 19, 2007]
- Moved misplaced test for malloc failure in png_set_sPLT(). This bug was
- introduced in libpng-1.2.20beta01.
- Ifdef out avg_row etc from png.h and pngwrite.c when PNG_NO_WRITE_FILTER
- Do not use png_ptr->free_fn and png_ptr->mem_fn in png_destroy_read_struct()
- when png_ptr is NULL (Marshall Clow).
- Updated handling of symbol prefixes in Makefile.am and configure.ac (Mike
- Frysinger).
-
-version 1.2.24beta02 [November 30, 2007]
- Removed a useless test and fixed incorrect test in png_set_cHRM_fixed()
- (David Hill).
-
-version 1.2.24rc01 [December 7, 2007]
- No changes.
-
-version 1.2.24 [December 14, 2007]
- Make sure not to redefine _BSD_SOURCE in pngconf.h
- Revised gather.sh and makefile.std in contrib/pngminim to avoid compiling
- unused files.
-
-version 1.2.25beta01 [January 7, 2008]
- Fixed bug with unknown chunk handling, introduced in version 1.2.17rc2
-
-version 1.2.25beta02 [January 10, 2008]
- Prevent gamma from being applied twice.
-
-version 1.2.25rc01 [January 17, 2008]
- No changes.
-
-version 1.2.25beta03 [January 22, 2008]
- Fixed some continue-after-malloc-failure errors in pngset.c (David Hill)
- Check for info_ptr == NULL in png_read_info() and png_process_data().
- Check for possible use of NULL user_png_ver[] in png_create_read_struct().
- Change "if (swidth == NULL)" to "if (sheight == NULL)" in png_handle_sCAL
- (bug introduced in libpng-1.2.4/1.0.13).
- Return from png_destroy_read_struct() if png_ptr_ptr is NULL.
- Fix overflow of "msg" in png_decompress_chunk().
-
-version 1.2.25beta04 [January 26, 2008]
- Work around Coverity bug report by slightly refactoring
- png_read_push_finish_row()
-
-version 1.2.25beta05 [January 31, 2008]
- Added libpng-1.2.25beta05.tar.lzma to distribution. Get the lzma codec
- from <http://tukaani.org/lzma>.
- Added lp1225b05.7z to distribution. Get the 7-zip decoder from
- from <http://www.7-zip.org>.
- Fixed some broken links in the README file.
-
-version 1.2.25beta06 [February 6, 2008]
- Refactored png_read_push_finish_row() again, trying to satisfy Coverity.
- Fixed potential NULL dereference of png_ptr in png_destroy_write_struct();
- clarified potential NULL dereference of png_ptr in png_destroy_read_struct();
- fixed potential NULL dereference of info_ptr in png_handle_bKGD();
- fixed potential NULL dereference of user_png_ver[] in
- png_create_write_struct_2(). (Coverity)
-
-version 1.2.25rc02 [February 10, 2008]
- Reset png_ptr->pass in png_read_push_finish_row() before break.
- Changed "pass" from png_byte to int.
-
-version 1.2.25 and 1.0.31 [February 18, 2008]
- No changes.
-
-version 1.2.26beta01 [February 21, 2008]
- Added missing "(" in pngmem.c. Bug introduced in libpng-1.2.2/1.0.13
-
-version 1.2.26beta02 [March 12, 2008]
- Refined error message returned from deflateInit2 in pngwutil.c
- Check IHDR length in png_push_read_chunk() before saving it.
-
-version 1.2.26beta03 [March 16, 2008]
- Revised contrib/gregbook to handle premature end-of-file and file
- read errors correctly.
-
-version 1.2.26beta04 [March 18, 2008]
- Free png_ptr->big_row_buf and png_ptr->prev_row before allocating
- new copies in png_read_start_row(). Bug introduced in libpng-1.2.22.
-
-version 1.2.26beta05 [March 19, 2008]
- Removed extra png_free() added in libpng-1.2.26beta04.
-
-version 1.2.26beta06 [March 19, 2008]
- Avoid reallocating big_row_buf and prev_row when the size does not increase.
-
-version 1.2.26rc01 [March 26, 2008]
- Ifdef out some code that is unused when interlacing is not supported.
-
-versions 1.0.32 and 1.2.26 [April 2, 2008]
- No changes.
-
-version 1.2.27beta01 [April 12, 2008]
- Fixed bug (introduced in libpng-1.0.5h) with handling zero-length
- unknown chunks.
- Added more information about png_set_keep_unknown_chunks() to the
- documentation.
- Reject tRNS chunk with out-of-range samples instead of masking off
- the invalid high bits as done in since libpng-1.2.19beta5.
-
-version 1.2.27beta02 [April 13, 2008]
- Revised documentation about unknown chunk and user chunk handling.
- Keep tRNS chunk with out-of-range samples and issue a png_warning().
-
-version 1.2.27beta03 [April 14, 2008]
- Added check for NULL ptr in TURBOC version of png_free_default().
- Removed several unnecessary checks for NULL before calling png_free().
- Revised png_set_tRNS() so that calling it twice removes and invalidates
- the previous call.
- Revised pngtest to check for out-of-range tRNS samples.
-
-version 1.2.27beta04 [April 18, 2008]
- Added AC_LIBTOOL_WIN32_DLL to configure.ac
- Rebuilt Makefile.in, aclocal.m4, and configure with autoconf-2.62
-
-version 1.2.27beta05 [April 19, 2008]
- Added MAINTAINERCLEANFILES variable to Makefile.am
-
-version 1.2.27beta06 [April 21, 2008]
- Avoid changing color_type from GRAY to RGB by
- png_set_expand_gray_1_2_4_to_8().
-
-version 1.2.27rc01 [April 23, 2008]
- Fix broken URL for rfc2083 in png.5 and libpng-*.txt
+Version 1.4.0beta1 [April 20, 2006]
+ Enabled iTXt support (changes png_struct, thus requires so-number change).
+ Cleaned up PNG_ASSEMBLER_CODE_SUPPORTED vs PNG_MMX_CODE_SUPPORTED
+ Eliminated PNG_1_0_X and PNG_1_2_X macros.
+ Removed deprecated functions png_read_init, png_write_init, png_info_init,
+ png_permit_empty_plte, png_set_gray_1_2_4_to_8, png_check_sig, and
+ removed the deprecated macro PNG_MAX_UINT.
+ Moved "PNG_INTERNAL" parts of png.h and pngconf.h into pngintrn.h
+ Removed many WIN32_WCE #ifdefs (Cosmin).
+ Reduced dependency on C-runtime library when on Windows (Simon-Pierre)
+ Replaced sprintf() with png_sprintf() (Simon-Pierre)
+
+Version 1.4.0beta2 [April 20, 2006]
+ Revised makefiles and configure to avoid making links to libpng.so.*
+ Moved some leftover MMX-related defines from pngconf.h to pngintrn.h
+ Updated scripts/pngos2.def, pngw32.def, and projects/wince/png32ce.def
-version 1.0.33 and 1.2.27 [April 30, 2008]
- No changes.
+Version 1.4.0beta3 [May 10, 2006]
+ Updated scripts/pngw32.def to comment out MMX functions.
+ Added PNG_NO_GET_INT_32 and PNG_NO_SAVE_INT_32 macros.
+ Scripts/libpng.pc.in contained "configure" style version info and would
+ not work with makefiles.
+ Revised pngconf.h and added pngconf.h.in, so makefiles and configure can
+ pass defines to libpng and applications.
-version 1.0.34 and 1.2.28 [April 30, 2008]
- Rebuilt Makefile.in, aclocal.m4, and configure with autoconf-2.61
- due to backward incompatibilities.
- Removed a stray object file from contrib/gregbook
+Version 1.4.0beta4 [May 11, 2006]
+ Revised configure.ac, Makefile.am, and many of the makefiles to write
+ their defines in pngconf.h.
-version 1.2.29beta01 [May 1, 2008]
- Removed some stray *.diff and *.orig files
+Version 1.4.0beta5 [May 15, 2006]
+ Added a missing semicolon in Makefile.am and Makefile.in
+ Deleted extraneous square brackets from configure.ac
-version 1.2.29beta02 [May 1, 2008]
- Reverted Makefile.in, aclocal.m4, and configure to the libpng-1.2.26
- versions.
+Version 1.4.0beta6 [June 2, 2006]
+ Increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
+ buffer overflow.
+ Changed sonum from 0 to 1.
+ Removed unused prototype for png_check_sig() from png.h
+
+Version 1.4.0beta7 [June 16, 2006]
+ Exported png_write_sig (Cosmin).
+ Optimized buffer in png_handle_cHRM() (Cosmin).
+ Set pHYs = 2835 x 2835 pixels per meter, and added
+ sCAL = 0.352778e-3 x 0.352778e-3 meters, in pngtest.png (Cosmin).
+ Added png_set_benign_errors(), png_benign_error(), png_chunk_benign_error().
+ Added typedef for png_int_32 and png_uint_32 on 64-bit systems.
+ Added "(unsigned long)" typecast on png_uint_32 variables in printf lists.
+
+Version 1.4.0beta8 [June 22, 2006]
+ Added demonstration of user chunk support in pngtest.c, to support the
+ public sTER chunk and a private vpAg chunk.
+
+Version 1.4.0beta9 [July 3, 2006]
+ Removed ordinals from scripts/pngw32.def and removed png_info_int and
+ png_set_gray_1_2_4_to_8 entries.
+ Inline call of png_get_uint_32() in png_get_uint_31().
+ Use png_get_uint_31() to get vpAg width and height in pngtest.c
+ Removed WINCE and Netware projects.
+ Removed standalone Y2KINFO file.
+
+Version 1.4.0beta10 [July 12, 2006]
+ Eliminated automatic copy of pngconf.h to pngconf.h.in from configure and
+ some makefiles, because it was not working reliably. Instead, distribute
+ pngconf.h.in along with pngconf.h and cause configure and some of the
+ makefiles to update pngconf.h from pngconf.h.in.
+ Added pngconf.h to DEPENDENCIES in Makefile.am
+
+Version 1.4.0beta11 [August 19, 2006]
+ Removed AC_FUNC_MALLOC from configure.ac.
+ Added a warning when writing iCCP profile with mismatched profile length.
+ Patched pnggccrd.c to assemble on x86_64 platforms.
+ Moved chunk header reading into a separate function png_read_chunk_header()
+ in pngrutil.c. The chunk header (len+sig) is now serialized in a single
+ operation (Cosmin).
+ Implemented support for I/O states. Added png_ptr member io_state, and
+ functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+ (Cosmin).
+ Added png_get_io_chunk_name and png_get_io_state to scripts/*.def (Cosmin).
+ Renamed scripts/pngw32.* to scripts/pngwin.* (Cosmin).
+ Removed the include directories and libraries from CFLAGS and LDFLAGS
+ in scripts/makefile.gcc (Cosmin).
+ Used png_save_uint_32() to set vpAg width and height in pngtest.c (Cosmin).
+ Cast to proper type when getting/setting vpAg units in pngtest.c (Cosmin).
+ Added pngintrn.h to the Visual C++ projects (Cosmin).
+ Removed scripts/list (Cosmin).
+ Updated copyright year in scripts/pngwin.def (Cosmin).
+ Removed PNG_TYPECAST_NULL and used standard NULL consistently (Cosmin).
+ Disallowed the user to redefine png_size_t, and enforced a consistent use
+ of png_size_t across libpng (Cosmin).
+ Changed the type of png_ptr->rowbytes, PNG_ROWBYTES() and friends
+ to png_size_t (Cosmin).
+ Removed png_convert_size() and replaced png_sizeof with sizeof (Cosmin).
+ Removed some unnecessary type casts (Cosmin).
+ Changed prototype of png_get_compression_buffer_size() and
+ png_set_compression_buffer_size() to work with png_size_t instead of
+ png_uint_32 (Cosmin).
+ Removed png_memcpy_check() and png_memset_check() (Cosmin).
+ Fixed a typo (png_byte --> png_bytep) in libpng.3 and libpng.txt (Cosmin).
+ Clarified that png_zalloc() does not clear the allocated memory,
+ and png_zalloc() and png_zfree() cannot be PNGAPI (Cosmin).
+ Renamed png_mem_size_t to png_alloc_size_t, fixed its definition in
+ pngconf.h, and used it in all memory allocation functions (Cosmin).
+ Renamed pngintrn.h to pngpriv.h, added a comment at the top of the file
+ mentioning that the symbols declared in that file are private, and
+ updated the scripts and the Visual C++ projects accordingly (Cosmin).
+ Removed circular references between pngconf.h and pngconf.h.in in
+ scripts/makefile.vc*win32 (Cosmin).
+ Removing trailing '.' from the warning and error messages (Cosmin).
+ Added pngdefs.h that is built by makefile or configure, instead of
+ pngconf.h.in (Glenn).
+ Detect and fix attempt to write wrong iCCP profile length.
-version 1.2.29beta03 [May 2, 2008]
- Added --force to autogen libtoolize options and --force-missing to
- automake options.
- Changed $(ECHO) to echo in Makefile.am and Makefile.in
- Updated all configure files to autoconf-2.62
- Comment out pnggcrd.c code with #ifdef/#endif if using MSC_VER
+Version 1.4.0beta12 [October 19, 2006]
+ Changed "logical" to "bitwise" in the documentation.
+ Work around Intel-Mac compiler bug by setting PNG_NO_MMX_CODE in pngconf.h
+ Add a typecast to stifle compiler warning in pngrutil.c
-version 1.2.29rc01 [May 4, 2008]
- No changes.
+Version 1.4.0beta13 [November 10, 2006]
+ Fix potential buffer overflow in sPLT chunk handler.
+ Fix Makefile.am to not try to link to noexistent files.
-version 1.0.35 and 1.2.29 [May 8, 2008]
- No changes.
+Version 1.4.0beta14 [November 15, 2006]
+ Check all exported functions for NULL png_ptr.
-version 1.0.37 [May 9, 2008]
- Updated Makefile.in and configure (omitted version 1.0.36).
+Version 1.4.0beta15 [November 17, 2006]
+ Relocated two misplaced tests for NULL png_ptr.
+ Built Makefile.in with automake-1.9.6 instead of 1.9.2.
+ Build configure with autoconf-2.60 instead of 2.59
+ Add "install: all" in Makefile.am so "configure; make install" will work.
-version 1.2.30beta01 [May 29, 2008]
- Updated libpng.pc-configure.in and libpng-config.in per debian bug reports.
+Version 1.4.0beta16 [November 17, 2006]
+ Added a typecast in png_zalloc().
-version 1.2.30beta02 [June 25, 2008]
- Restored png_flush(png_ptr) at the end of png_write_end(), that was
- removed from libpng-1.0.9beta03.
+Version 1.4.0beta17 [December 4, 2006]
+ Changed "new_key[79] = '\0';" to "(*new_key)[79] = '\0';" in pngwutil.c
+ Add "png_bytep" typecast to profile while calculating length in pngwutil.c
-version 1.2.30beta03 [July 6, 2008]
- Merged some cosmetic whitespace changes from libpng-1.4.0beta19.
- Inline call of png_get_uint_32() in png_get_uint_31(), as in 1.4.0beta19.
- Added demo of decoding vpAg and sTER chunks to pngtest.c, from 1.4.0beta19.
- Changed PNGMAJ from 0 to 12 in makefile.darwin, which does not like 0.
- Added new private function png_read_chunk_header() from 1.4.0beta19.
- Merge reading of chunk length and chunk type into a single 8-byte read.
- Merge writing of chunk length and chunk type into a single 8-byte write.
+Version 1.4.0beta18 [December 7, 2006]
+ Added scripts/CMakeLists.txt
-version 1.2.30beta04 [July 10, 2008]
- Merged more cosmetic whitespace changes from libpng-1.4.0beta19.
+Version 1.4.0beta19 [May 16, 2007]
+ Revised scripts/CMakeLists.txt
+ Rebuilt configure and Makefile.in with newer tools.
+ Added conditional #undef jmpbuf in pngtest.c to undo #define in AIX headers.
+ Added scripts/makefile.nommx
-version 1.0.38rc01, 1.2.30rc01 [July 18, 2008]
- No changes.
+Version 1.4.0beta20 [July 9, 2008]
+ Moved several PNG_HAVE_* macros from pngpriv.h to png.h because applications
+ calling set_unknown_chunk_location() need them.
+ Moved several macro definitions from pngpriv.h to pngconf.h
+ Merge with changes to the 1.2.X branch, as of 1.2.30beta04.
+ Deleted all use of the MMX assembler code and Intel-licensed optimizations.
+ Revised makefile.mingw
-version 1.0.38rc02, 1.2.30rc02 [July 21, 2008]
+Version 1.4.0beta21 [July 21, 2008]
Moved local array "chunkdata" from pngrutil.c to the png_struct, so
it will be freed by png_read_destroy() in case of a read error (Kurt
Christensen).
-version 1.0.38rc03, 1.2.30rc03 [July 21, 2008]
- Changed "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
+Version 1.4.0beta22 [July 21, 2008]
+ Change "purpose" and "buffer" to png_ptr->chunkdata to avoid memory leaking.
-version 1.0.38rc04, 1.2.30rc04 [July 22, 2008]
- Changed "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
+Version 1.4.0beta23 [July 22, 2008]
+ Change "chunkdata = NULL" to "png_ptr->chunkdata = NULL" several places in
png_decompress_chunk().
-version 1.0.38rc05, 1.2.30rc05 [July 25, 2008]
- Changed all remaining "chunkdata" to "png_ptr->chunkdata" in
- png_decompress_chunk() and remove chunkdata from parameter list.
+Version 1.4.0beta24 [July 25, 2008]
+ Change all remaining "chunkdata" to "png_ptr->chunkdata" in
+ png_decompress_chunk(), and remove "chunkdata" from parameter list.
Put a call to png_check_chunk_name() in png_read_chunk_header().
Revised png_check_chunk_name() to reject a name with a lowercase 3rd byte.
- Removed two calls to png_check_chunk_name() occuring later in the process.
+ Removed two calls to png_check_chunk_name() occurring later in the process.
+ Define PNG_NO_ERROR_NUMBERS by default in pngconf.h
-version 1.0.38rc06, 1.2.30rc06 [July 29, 2008]
+Version 1.4.0beta25 [July 30, 2008]
Added a call to png_check_chunk_name() in pngpread.c
Reverted png_check_chunk_name() to accept a name with a lowercase 3rd byte.
+ Added png_push_have_buffer() function to pngpread.c
+ Eliminated PNG_BIG_ENDIAN_SUPPORTED and associated png_get_* macros.
+ Made inline expansion of png_get_*() optional with PNG_USE_READ_MACROS.
+ Eliminated all PNG_USELESS_TESTS and PNG_CORRECT_PALETTE_SUPPORTED code.
+ Synced contrib directory and configure files with libpng-1.2.30beta06.
+ Eliminated no-longer-used pngdefs.h (but it's still built in the makefiles)
+ Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
-version 1.0.38r07, 1.2.30r07 [August 2, 2008]
+Version 1.4.0beta26 [August 4, 2008]
+ Removed png_push_have_buffer() function in pngpread.c. It increased the
+ compiled library size slightly.
Changed "-Wall" to "-W -Wall" in the CFLAGS in all makefiles (Cosmin Truta)
Declared png_ptr "volatile" in pngread.c and pngwrite.c to avoid warnings.
- Added code in pngset.c to quiet compiler warnings.
Updated contrib/visupng/cexcept.h to version 2.0.1
- Relocated a misplaced "#endif /* PNG_NO_WRITE_FILTER */" in pngwutil.c
+ Added PNG_LITERAL_CHARACTER macros for #, [, and ].
-version 1.0.38r08, 1.2.30r08 [August 2, 2008]
- Enclose "volatile" declarations in #ifdef PNG_SETJMP_SUPPORTED (Cosmin).
+Version 1.4.0beta27 [August 5, 2008]
+ Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+ Moved newline character from individual png_debug messages into the
+ png_debug macros.
+ Allow user to #define their own png_debug, png_debug1, and png_debug2.
-version 1.0.38, 1.2.30 [August 14, 2008]
- No changes.
+Version 1.4.0beta28 [August 5, 2008]
+ Revised usage of PNG_LITERAL_SHARP in pngerror.c.
+ Added PNG_STRING_NEWLINE macro
+
+Version 1.4.0beta29 [August 9, 2008]
+ Revised usage of PNG_STRING_NEWLINE to work on non-ISO compilers.
+ Added PNG_STRING_COPYRIGHT macro.
+ Added non-ISO versions of png_debug macros.
-version 1.2.31rc01 [August 19, 2008]
+Version 1.4.0beta30 [August 14, 2008]
+ Added premultiplied alpha feature (Volker Wiendl).
+
+Version 1.4.0beta31 [August 18, 2008]
+ Moved png_set_premultiply_alpha from pngtrans.c to pngrtran.c
Removed extra crc check at the end of png_handle_cHRM(). Bug introduced
- in libpng-1.2.30beta03 (Heiko Nitzsche).
+ in libpng-1.4.0beta20.
-version 1.2.31rc02 [August 19, 2008]
+Version 1.4.0beta32 [August 19, 2008]
Added PNG_WRITE_FLUSH_SUPPORTED block around new png_flush() call.
+ Revised PNG_NO_STDIO version of png_write_flush()
-version 1.2.31rc03 [August 19, 2008]
- Added PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED block, off by default, around
- new png_flush().
+Version 1.4.0beta33 [August 20, 2008]
+ Added png_get|set_chunk_cache_max() to limit the total number of sPLT,
+ text, and unknown chunks that can be stored.
-version 1.0.39, 1.2.31 [August 21, 2008]
- No changes.
-
-version 1.2.32beta01 [September 6, 2008]
- Shortened tIME_string to 29 bytes in pngtest.c (bug introduced in
- libpng-1.2.22).
+Version 1.4.0beta34 [September 6, 2008]
+ Shortened tIME_string to 29 bytes in pngtest.c
Fixed off-by-one error introduced in png_push_read_zTXt() function in
libpng-1.2.30beta04/pngpread.c (Harald van Dijk)
- These bugs have been given the vulnerability id CVE-2008-3964.
-
-version 1.0.40, 1.2.32 [September 18, 2008]
- No changes.
-version 1.2.33beta01 [October 6, 2008]
+Version 1.4.0beta35 [October 6, 2008]
+ Changed "trans_values" to "trans_color".
+ Changed so-number from 0 to 14. Some OS do not like 0.
Revised makefile.darwin to fix shared library numbering.
Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
in example.c (debian bug report)
-version 1.2.33rc01 [October 15, 2008]
- No changes.
+Version 1.4.0beta36 [October 25, 2008]
+ Sync with tEXt vulnerability fix in libpng-1.2.33rc02.
-version 1.0.41rc01, version 1.2.33rc02 [October 23, 2008]
- Changed remaining "key" to "png_ptr->chunkdata" in png_handle_tEXt()
- to avoid memory leak after memory failure while reading tEXt chunk.`
+Version 1.4.0beta37 [November 13, 2008]
+ Added png_check_cHRM in png.c and moved checking from pngget.c, pngrutil.c,
+ and pngwrite.c
-version 1.2.33 [October 31, 2008]
- No changes.
+Version 1.4.0beta38 [November 22, 2008]
+ Added check for zero-area RGB cHRM triangle in png_check_cHRM() and
+ png_check_cHRM_fixed().
-version 1.2.34beta01 [November 27, 2008]
- Revised png_warning() to write its message on standard output by default
- when warning_fn is NULL. This was the behavior prior to libpng-1.2.9beta9.
- Fixed string vs pointer-to-string error in png_check_keyword().
- Added png_check_cHRM_fixed() in png.c and moved checking from pngget.c,
- pngrutil.c, and pngwrite.c, and eliminated floating point cHRM checking.
- Added check for zero-area RGB cHRM triangle in png_check_cHRM_fixed().
- In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
- check for all-zero coordinates that is detected by the triangle check.
+Version 1.4.0beta39 [November 23, 2008]
Revised png_warning() to write its message on standard output by default
when warning_fn is NULL.
-version 1.2.34beta02 [November 28, 2008]
- Corrected off-by-one error in bKGD validity check in png_write_bKGD()
- and in png_handle_bKGD().
+Version 1.4.0beta40 [November 24, 2008]
+ Eliminated png_check_cHRM(). Instead, always use png_check_cHRM_fixed().
+ In png_check_cHRM_fixed(), ensure white_y is > 0, and removed redundant
+ check for all-zero coordinates that is detected by the triangle check.
-version 1.2.34beta03 [December 1, 2008]
- Revised bKGD validity check to use >= x instead of > x + 1
- Merged with png_debug from libpng-1.4.0 to remove newlines.
+Version 1.4.0beta41 [November 26, 2008]
+ Fixed string vs pointer-to-string error in png_check_keyword().
+ Rearranged test expressions in png_check_cHRM_fixed() to avoid internal
+ overflows.
+ Added PNG_NO_CHECK_cHRM conditional.
-version 1.2.34beta04 [December 2, 2008]
- More merging with png_debug from libpng-1.4.0 to remove newlines.
+Version 1.4.0beta42, 43 [December 1, 2008]
+ Merge png_debug with version 1.2.34beta04.
-version 1.2.34beta05 [December 5, 2008]
+Version 1.4.0beta44 [December 6, 2008]
Removed redundant check for key==NULL before calling png_check_keyword()
to ensure that new_key gets initialized and removed extra warning
- (Arvan Pritchard).
+ (Merge with version 1.2.34beta05 -- Arvan Pritchard).
-version 1.2.34beta06 [December 9, 2008]
+Version 1.4.0beta45 [December 9, 2008]
In png_write_png(), respect the placement of the filler bytes in an earlier
call to png_set_filler() (Jim Barry).
-version 1.2.34beta07 [December 9, 2008]
+Version 1.4.0beta46 [December 10, 2008]
Undid previous change and added PNG_TRANSFORM_STRIP_FILLER_BEFORE and
PNG_TRANSFORM_STRIP_FILLER_AFTER conditionals and deprecated
PNG_TRANSFORM_STRIP_FILLER (Jim Barry).
-version 1.0.42rc01, 1.2.34rc01 [December 11, 2008]
- No changes.
-
-version 1.0.42, 1.2.34 [December 18, 2008]
- No changes.
-
-version 1.2.35beta01 [February 4, 2009]
- Zero out some arrays of pointers after png_malloc(). (Tavis Ormandy)
-
-version 1.2.35beta02 [February 4, 2009]
- Zero out more arrays of pointers after png_malloc().
-
-version 1.2.35beta03 [February 5, 2009]
- Use png_memset() instead of a loop to intialize pointers. We realize
- this will not work on platforms where the NULL pointer is not all zeroes.
-
-version 1.2.35rc01 [February 11, 2009]
- No changes.
+Version 1.4.0beta47 [December 15, 2008]
+ Support for dithering was disabled by default, because it has never
+ been well tested and doesn't work very well. The code has not
+ been removed, however, and can be enabled by building libpng with
+ PNG_READ_DITHER_SUPPORTED defined.
+
+Version 1.4.0beta48 [February 14, 2009]
+ Added new exported function png_calloc().
+ Combined several instances of png_malloc(); png_memset() into png_calloc().
+ Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+ but was never defined.
+
+Version 1.4.0beta49 [February 28, 2009]
+ Added png_fileno() macro to pngconf.h, used in pngwio.c
+ Corrected order of #ifdef's in png_debug definition in png.h
+ Fixed bug introduced in libpng-1.4.0beta48 with the memset arguments
+ for pcal_params.
+ Fixed order of #ifdef directives in the png_debug defines in png.h
+ (bug introduced in libpng-1.2.34/1.4.0beta29).
+ Revised comments in png_set_read_fn() and png_set_write_fn().
-version 1.2.35rc02 [February 12, 2009]
- Fix typo in new png_memset call in pngset.c (png_color should be png_charp)
+Version 1.4.0beta50 [March 18, 2009]
+ Use png_calloc() instead of png_malloc() to allocate big_row_buf when
+ reading an interlaced file, to avoid a possible UMR.
+ Undid revision of PNG_NO_STDIO version of png_write_flush(). Users
+ having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined
+ or supply their own flush_fn() replacement.
+ Revised libpng*.txt and png.h documentation about use of png_write_flush()
+ and png_set_write_fn().
+ Removed fflush() from pngtest.c.
+ Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
-version 1.0.43 and 1.2.35 [February 14, 2009]
- No changes.
+Version 1.4.0beta51 [March 21, 2009]
+ Removed new png_fileno() macro from pngconf.h .
-version 1.2.36beta01 [February 28, 2009]
- Revised comments in png_set_read_fn() and png_set_write_fn().
- Revised order of #ifdef's and indentation in png_debug definitions of png.h
- bug introduced in libpng-1.2.34.
-
-version 1.2.36beta02 [March 21, 2009]
- Use png_memset() after png_malloc() of big_row_buf when reading an
- interlaced file, to avoid a possible UMR.
- Undid recent revision of PNG_NO_STDIO version of png_write_flush(). Users
- having trouble with fflush() can build with PNG_NO_WRITE_FLUSH defined.
- Revised libpng*.txt documentation about use of png_write_flush().
+Version 1.4.0beta52 [March 27, 2009]
+ Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
+ This avoids building 16-bit gamma tables unnecessarily.
Removed fflush() from pngtest.c.
Added "#define PNG_NO_WRITE_FLUSH" to contrib/pngminim/encoder/pngusr.h
-
-version 1.2.36beta03 [March 27, 2009]
- Relocated misplaced PNG_1_0_X define in png.h that caused the prototype
- for png_set_strip_error_numbers() to be omitted from PNG_NO_ASSEMBLER_CODE
- builds. This bug was introduced in libpng-1.2.15beta4.
Added a section on differences between 1.0.x and 1.2.x to libpng.3/libpng.txt
-version 1.2.36beta04 [April 5, 2009]
+Version 1.4.0beta53 [April 1, 2009]
+ Removed some remaining MMX macros from pngpriv.h
Fixed potential memory leak of "new_name" in png_write_iCCP() (Ralph Giles)
-version 1.2.36beta05 [April 24, 2009]
+Version 1.4.0beta54 [April 13, 2009]
Added "ifndef PNG_SKIP_SETJMP_CHECK" block in pngconf.h to allow
application code writers to bypass the check for multiple inclusion
of setjmp.h when they know that it is safe to ignore the situation.
- Made some cosmetic changes to whitespace in pngtest output.
+ Eliminated internal use of setjmp() in pngread.c and pngwrite.c
+ Reordered ancillary chunks in pngtest.png to be the same as what
+ pngtest now produces, and made some cosmetic changes to pngtest output.
+ Eliminated deprecated png_read_init_3() and png_write_init_3() functions.
+
+Version 1.4.0beta55 [April 15, 2009]
+ Simplified error handling in pngread.c and pngwrite.c by putting
+ the new png_read_cleanup() and png_write_cleanup() functions inline.
+
+Version 1.4.0beta56 [April 25, 2009]
Renamed "user_chunk_data" to "my_user_chunk_data" in pngtest.c to suppress
"shadowed declaration" warning from gcc-4.3.3.
Renamed "gamma" to "png_gamma" in pngset.c to avoid "shadowed declaration"
warning about a global "gamma" variable in math.h on some platforms.
-version 1.2.36rc01 [April 30, 2009]
- No changes.
-
-version 1.0.44 and 1.2.36 [May 7, 2009]
- No changes.
+Version 1.4.0beta57 [May 2, 2009]
+ Removed prototype for png_freeptr() that was added in libpng-1.4.0beta24
+ but was never defined (again).
+ Rebuilt configure scripts with autoconf-2.63 instead of 2.62
+ Removed pngprefs.h and MMX from makefiles
-version 1.2.37beta01 [May 14, 2009]
- Fixed inconsistency in pngrutil.c, introduced in libpng-1.2.36. The
- memset() was using "png_ptr->rowbytes" instead of "row_bytes", which
- the corresponding png_malloc() uses (Joe Drew).
+Version 1.4.0beta58 [May 14, 2009]
+ Changed pngw32.def to pngwin.def in makefile.mingw (typo was introduced
+ in beta57).
Clarified usage of sig_bit versus sig_bit_p in example.c (Vincent Torri)
- Updated some of the makefiles in the scripts directory (merged with
- those in libpng-1.4.0beta57).
-version 1.2.37beta02 [May 19, 2009]
- Fixed typo in libpng documentation (FILTER_AVE should be FILTER_AVG)
+Version 1.4.0beta59 [May 15, 2009]
+ Reformated sources in libpng style (3-space intentation, comment format)
+ Fixed typo in libpng docs (PNG_FILTER_AVE should be PNG_FILTER_AVG)
+ Added sections about the git repository and our coding style to the
+ documentation
Relocated misplaced #endif in pngwrite.c, sCAL chunk handler.
+
+Version 1.4.0beta60 [May 19, 2009]
Conditionally compile png_read_finish_row() which is not used by
progressive readers.
Added contrib/pngminim/preader to demonstrate building minimal progressive
decoder, based on contrib/gregbook with embedded libpng and zlib.
-version 1.2.37beta03 [May 20, 2009]
+Version 1.4.0beta61 [May 20, 2009]
In contrib/pngminim/*, renamed "makefile.std" to "makefile", since there
is only one makefile in those directories, and revised the README files
accordingly.
- Reformated sources in libpng style (3-space indentation, comment format)
+ More reformatting of comments, mostly to capitalize sentences.
-version 1.2.37rc01 [May 27, 2009]
- No changes.
-
-versions 1.2.37 and 1.0.45 [June 4, 2009]
- Reformatted several remaining "else statement;" and "if () statement;" into
- two lines.
+Version 1.4.0beta62 [June 2, 2009]
Added "#define PNG_NO_WRITE_SWAP" to contrib/pngminim/encoder/pngusr.h
and "define PNG_NO_READ_SWAP" to decoder/pngusr.h and preader/pngusr.h
- Added sections about the git repository and our coding style to the
- documentation (merged from libpng-1.4.0beta62)
+ Reformatted several remaining "else statement" into two lines.
Added a section to the libpng documentation about using png_get_io_ptr()
in configure scripts to detect the presence of libpng.
-version 1.2.38beta01 [June 17, 2009]
+Version 1.4.0beta63 [June 15, 2009]
Revised libpng*.txt and libpng.3 to mention calling png_set_IHDR()
multiple times and to specify the sample order in the tRNS chunk,
because the ISO PNG specification has a typo in the tRNS table.
@@ -2411,154 +2329,143 @@ version 1.2.38beta01 [June 17, 2009]
available for ignoring known chunks even when not saving unknown chunks.
Adopted preference for consistent use of "#ifdef" and "#ifndef" versus
"#if defined()" and "if !defined()" where possible.
- Added PNG_NO_HANDLE_AS_UNKNOWN in the PNG_LEGACY_SUPPORTED block of
- pngconf.h, and moved the various unknown chunk macro definitions
- outside of the PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
-version 1.0.46 [June 18, 2009]
- Removed some editing cruft from scripts/libpng.pc.in and some makefiles.
+Version 1.4.0beta64 [June 24, 2009]
+ Eliminated PNG_LEGACY_SUPPORTED code.
+ Moved the various unknown chunk macro definitions outside of the
+ PNG_READ|WRITE_ANCILLARY_CHUNK_SUPPORTED blocks.
-version 1.2.38rc01 [June 24, 2009]
- No changes.
+Version 1.4.0beta65 [June 26, 2009]
+ Added a reference to the libpng license in each file.
-version 1.2.38rc02 [June 29, 2009]
- Added a reference to the libpng license in each source file.
+Version 1.4.0beta66 [June 27, 2009]
+ Refer to the libpng license instead of the libpng license in each file.
-version 1.2.38rc03 [July 11, 2009]
- Revised references to the libpng license in pngconf.h and contrib/visupng
- source files.
- Rebuilt configure scripts with autoconf-2.63.
+Version 1.4.0beta67 [July 6, 2009]
+ Relocated INVERT_ALPHA within png_read_png() and png_write_png().
+ Added high-level API transform PNG_TRANSFORM_GRAY_TO_RGB.
+ Added an "xcode" project to the projects directory (Alam Arias).
-version 1.0.47 and 1.2.38 [July 16, 2009]
- No changes.
+Version 1.4.0beta68 [July 19, 2009]
+ Avoid some tests in filter selection in pngwutil.c
-version 1.2.39beta01 [July 25, 2009]
+Version 1.4.0beta69 [July 25, 2009]
+ Simplified the new filter-selection test. This runs faster in the
+ common "PNG_ALL_FILTERS" and PNG_FILTER_NONE cases.
+ Removed extraneous declaration from the new call to png_read_gray_to_rgb()
+ (bug introduced in libpng-1.4.0beta67).
+ Fixed up xcode project (Alam Arias)
Added a prototype for png_64bit_product() in png.c
-version 1.2.39beta02 [July 27, 2009]
+Version 1.4.0beta70 [July 27, 2009]
Avoid a possible NULL dereference in debug build, in png_set_text_2().
(bug introduced in libpng-0.95, discovered by Evan Rouault)
-version 1.2.39beta03 [July 29, 2009]
- Relocated new png_64_bit_product() prototype into png.h
- Expanded the information about prototypes in the libpng style section of
- the documentation.
+Version 1.4.0beta71 [July 29, 2009]
Rebuilt configure scripts with autoconf-2.64.
-version 1.2.39beta04 [August 1, 2009]
- Replaced *.tar.lzma with *.txz in distribution. Get the xz codec
+Version 1.4.0beta72 [August 1, 2009]
+ Replaced *.tar.lzma with *.tar.xz in distribution. Get the xz codec
from <http://tukaani.org/xz>.
-version 1.2.39beta05 [August 1, 2009]
+Version 1.4.0beta73 [August 1, 2009]
Reject attempt to write iCCP chunk with negative embedded profile length
- (JD Chen)
+ (JD Chen) (CVE-2009-5063).
-version 1.2.39c01 [August 6, 2009]
- No changes.
+Version 1.4.0beta74 [August 8, 2009]
+ Changed png_ptr and info_ptr member "trans" to "trans_alpha".
-version 1.2.39 and 1.0.48 [August 13, 2009]
- No changes.
-
-version 1.2.40beta01 [August 20, 2009]
+Version 1.4.0beta75 [August 21, 2009]
Removed an extra png_debug() recently added to png_write_find_filter().
Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
-version 1.2.40rc01 [September 2, 2009]
- Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
+Version 1.4.0beta76 [August 22, 2009]
+ Moved an incorrectly located test in png_read_row() in pngread.c
-version 1.2.40 and 1.0.49 [September 2, 2009]
- No changes.
+Version 1.4.0beta77 [August 27, 2009]
+ Removed lpXYZ.tar.bz2 (with CRLF), KNOWNBUG, libpng-x.y.z-KNOWNBUG.txt,
+ and the "noconfig" files from the distribution.
+ Moved CMakeLists.txt from scripts into the main libpng directory.
+ Various bugfixes and improvements to CMakeLists.txt (Philip Lowman)
-version 1.0.50 [September 10, 2009]
- Removed some editing cruft from pngset.c and pngwutil.c.
+Version 1.4.0beta78 [August 31, 2009]
+ Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
+ Eliminated PNG_NO_FREE_ME and PNG_FREE_ME_SUPPORTED macros.
+ Use png_malloc plus a loop instead of png_calloc() to initialize
+ row_pointers in png_read_png().
+
+Version 1.4.0beta79 [September 1, 2009]
+ Eliminated PNG_GLOBAL_ARRAYS and PNG_LOCAL_ARRAYS; always use local arrays.
+ Eliminated PNG_CALLOC_SUPPORTED macro and always provide png_calloc().
+
+Version 1.4.0beta80 [September 17, 2009]
+ Removed scripts/libpng.icc
+ Changed typecast of filler from png_byte to png_uint_16 in png_set_filler().
+ (Dennis Gustafsson)
+ Fixed typo introduced in beta78 in pngtest.c ("#if def " should be "#ifdef ")
+
+Version 1.4.0beta81 [September 23, 2009]
+ Eliminated unused PNG_FLAG_FREE_* defines from pngpriv.h
+ Expanded TAB characters in pngrtran.c
+ Removed PNG_CONST from all "PNG_CONST PNG_CHNK" declarations to avoid
+ compiler complaints about doubly declaring things "const".
+ Changed all "#if [!]defined(X)" to "if[n]def X" where possible.
+ Eliminated unused png_ptr->row_buf_size
-version 1.2.41beta01 [September 25, 2009]
+Version 1.4.0beta82 [September 25, 2009]
Moved redundant IHDR checking into new png_check_IHDR() in png.c
and report all errors found in the IHDR data.
Eliminated useless call to png_check_cHRM() from pngset.c
- Expanded TAB characters in pngrtran.c
-version 1.2.41beta02 [September 30, 2009]
- Revised png_check_IHDR().
+Version 1.4.0beta83 [September 25, 2009]
+ Revised png_check_IHDR() to eliminate bogus complaint about filter_type.
+
+Version 1.4.0beta84 [September 30, 2009]
+ Fixed some inconsistent indentation in pngconf.h
+ Revised png_check_IHDR() to add a test for width variable less than 32-bit.
-version 1.2.41beta03 [October 1, 2009]
+Version 1.4.0beta85 [October 1, 2009]
Revised png_check_IHDR() again, to check info_ptr members instead of
the contents of the returned parameters.
-version 1.2.41beta04 [October 7, 2009]
- Added "xcode" project similar one already in libpng-1.4.0beta (Alam Arias).
- Ported some cosmetic changes from libpng-1.4.0beta86.
+Version 1.4.0beta86 [October 9, 2009]
+ Updated the "xcode" project (Alam Arias).
Eliminated a shadowed declaration of "pp" in png_handle_sPLT().
-version 1.2.41beta05 [October 17, 2009]
- Revised pngconf.h to make it easier to enable iTXt support. From libpng
- version 1.2.9 through 1.2.40, defining PNG_iTXt_SUPPORTED did not work
- as expected.
- Ported some cosmetic changes from libpng-1.4.0beta87, changing
- many "#if defined(x)" to "#ifdef x".
+Version 1.4.0rc01 [October 19, 2009]
+ Trivial cosmetic changes.
-version 1.2.41beta06 [October 18, 2009]
- Restored PNG_USE_LOCAL_ARRAYS code in pngread.c that was inadvertently
- deleted in libpng-1.2.41beta05.
- Converted all PNG_NO_* tests to PNG_*_SUPPORTED everywhere except pngconf.h
- as in libpng-1.4.0beta78 and later.
+Version 1.4.0beta87 [October 30, 2009]
+ Moved version 1.4.0 back into beta.
-version 1.2.41beta07 [October 21, 2009]
- Ported some cosmetic changes from libpng-1.4.0rc01, changing
- many "#if defined(x)" to "#ifdef x" in png.h and pngconf.h.
+Version 1.4.0beta88 [October 30, 2009]
+ Revised libpng*.txt section about differences between 1.2.x and 1.4.0
+ because most of the new features have now been ported back to 1.2.41
-version 1.2.41beta08 [October 30, 2009]
- Ported from libpng-1.4.0rc01: png_calloc(), png_get_io_chunk_name(),
- png_get_io_state(), png_set_user_cache_max(), png_get_user_cache_max(),
- png_set_premultiply_alpha, and png_do_read_premultiply_alpha().
- Relocated png_do_chop() ahead of building gamma tables in pngrtran.c
- This avoids building 16-bit gamma tables unnecessarily.
-
-version 1.2.41beta09 [November 1, 2009]
- Removed a harmless extra png_set_invert_alpha() from pngwrite.c
+Version 1.4.0beta89 [November 1, 2009]
More bugfixes and improvements to CMakeLists.txt (Philip Lowman)
- Moved CMakeLists.txt from scripts into the main libpng directory.
+ Removed a harmless extra png_set_invert_alpha() from pngwrite.c
Apply png_user_chunk_cache_max within png_decompress_chunk().
Merged libpng-1.2.41.txt with libpng-1.4.0.txt where appropriate.
-version 1.2.41beta10 [November 1, 2009]
- Enabled iTXt support by default. To ensure binary compatibility with
- previous versions, the "lang" and "lang_key" members will be assumed
- to be omitted from previous versions unless the current libpng
- version was built with PNG_iTXt_SUPPORTED (which is otherwise no
- longer necessary to gain iTXt support), as a signal that the user has
- been building previous versions with PNG_iTXt_SUPPORTED as well.
-
-version 1.2.41beta11 [November 2, 2009]
- Store user's user_png_ver in new png_ptr->user_png_ver element.
- Revised iTXt support. To ensure binary compatibility with
- previous versions, the "lang" and "lang_key" members will be assumed
- to be omitted from versions prior to 1.2.41beta11 whenever there is a
- library mismatch.
-
-version 1.2.41beta12 [November 2, 2009]
- Free png_ptr->user_png_ver when destroying png_ptr.
-
-version 1.2.41beta13 [November 3, 2009]
+Version 1.4.0beta90 [November 2, 2009]
+ Removed all remaining WIN32_WCE #ifdefs except those involving the
+ time.h "tm" structure
+
+Version 1.4.0beta91 [November 3, 2009]
Updated scripts/pngw32.def and projects/wince/png32ce.def
Copied projects/wince/png32ce.def to the scripts directory.
Added scripts/makefile.wce
Patched ltmain.sh for wince support.
Added PNG_CONVERT_tIME_SUPPORTED macro.
-version 1.2.41beta14 [November 8, 2009]
- versions 1.2.41beta05 through 1.2.41beta13 were abandoned.
- The 1.0.x/1.2.x series will only receive security updates from now on.
+Version 1.4.0beta92 [November 4, 2009]
Make inclusion of time.h in pngconf.h depend on PNG_CONVERT_tIME_SUPPORTED
Make #define PNG_CONVERT_tIME_SUPPORTED depend on PNG_WRITE_tIME_SUPPORTED
- Reverted iTXt compatibility stuff from 1.2.41beta05, 1.2.41beta11, and
- 1.2.41beta12.
- Reverted IOSTATE feature, user_cache_max, and premultiply_alpha features
- from 1.2.41beta08.
- Retained png_calloc() from 1.2.41beta08 but as a non-exported function,
- and removed reference to png_calloc from scripts/*.def
-
-version 1.2.41beta15 [November 8, 2009]
+ Revised libpng*.txt to describe differences from 1.2.40 to 1.4.0 (instead
+ of differences from 1.2.41 to 1.4.0)
+
+Version 1.4.0beta93 [November 7, 2009]
Added PNG_DEPSTRUCT, PNG_DEPRECATED, PNG_USE_RESULT, PNG_NORETURN, and
PNG_ALLOCATED macros to detect deprecated direct access to the
png_struct or info_struct members and other deprecated usage in
@@ -2568,147 +2475,3622 @@ version 1.2.41beta15 [November 8, 2009]
functions while building libpng. They need to be tested, especially
those using compilers other than gcc.
Updated projects/visualc6 and visualc71 with "/d PNG_CONFIGURE_LIBPNG".
-
-version 1.2.41beta16 [November 9, 2009]
+ They should work but still need to be updated to remove
+ references to pnggccrd.c or pngvcrd.c and ASM building.
+ Added README.txt to the beos, cbuilder5, netware, and xcode projects warning
+ that they need to be updated, to remove references to pnggccrd.c and
+ pngvcrd.c and to depend on pngpriv.h
Removed three direct references to read_info_ptr members in pngtest.c
that were detected by the new PNG_DEPSTRUCT macro.
+ Moved the png_debug macro definitions and the png_read_destroy(),
+ png_write_destroy() and png_far_to_near() prototypes from png.h
+ to pngpriv.h (John Bowler)
+ Moved the synopsis lines for png_read_destroy(), png_write_destroy()
+ png_debug(), png_debug1(), and png_debug2() from libpng.3 to libpngpf.3.
+
+Version 1.4.0beta94 [November 9, 2009]
+ Removed the obsolete, unused pnggccrd.c and pngvcrd.c files.
+ Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
+ Removed dependency of pngtest.o on pngpriv.h in the makefiles.
Only #define PNG_DEPSTRUCT, etc. in pngconf.h if not already defined.
-version 1.2.41beta17 [November 10, 2009]
- Updated CMakeLists.txt to add "-DPNG_CONFIGURE_LIBPNG" to the definitions.
- Marked deprecated function prototypes with PNG_DEPRECATED.
- Marked memory allocation function prototypes with PNG_ALLOCATED.
+Version 1.4.0beta95 [November 10, 2009]
+ Changed png_check_sig() to !png_sig_cmp() in contrib programs.
+ Added -DPNG_CONFIGURE_LIBPNG to contrib/pngminm/*/makefile
Changed png_check_sig() to !png_sig_cmp() in contrib programs.
Corrected the png_get_IHDR() call in contrib/gregbook/readpng2.c
- Added "-DPNG_CONFIGURE_LIBPNG" to the contrib/pngminum makefiles.
+ Changed pngminim/*/gather.sh to stop trying to remove pnggccrd.c and pngvcrd.c
+ Added dependency on pngpriv.h in contrib/pngminim/*/makefile
-version 1.2.41beta18 [November 11, 2009]
+Version 1.4.0beta96 [November 12, 2009]
Renamed scripts/makefile.wce to scripts/makefile.cegcc
- Marked nonexported functions with PNG_PRIVATE macro.
-
-version 1.2.41rc01 and 1.0.51rc01 [November 18, 2009]
- Revised scripts/*.def to reflect functions actually exported by libpng.
- Updated the copyright year in scripts/pngw32.rc from 2004 to 2009.
+ Revised Makefile.am to use libpng.sys while building libpng.so
+ so that only PNG_EXPORT functions are exported.
+ Removed the deprecated png_check_sig() function/macro.
+ Removed recently removed function names from scripts/*.def
+ Revised pngtest.png to put chunks in the same order written by pngtest
+ (evidently the same change made in libpng-1.0beta54 was lost).
+ Added PNG_PRIVATE macro definition in pngconf.h for possible future use.
+
+Version 1.4.0beta97 [November 13, 2009]
+ Restored pngtest.png to the libpng-1.4.0beta7 version.
+ Removed projects/beos and netware.txt; no one seems to be supporting them.
+ Revised Makefile.in
+
+Version 1.4.0beta98 [November 13, 2009]
+ Added the "xcode" project to zip distributions,
+ Fixed a typo in scripts/pngwin.def introduced in beta97.
+
+Version 1.4.0beta99 [November 14, 2009]
+ Moved libpng-config.in and libpng.pc-configure.in out of the scripts
+ directory, to libpng-config.in and libpng-pc.in, respectively, and
+ modified Makefile.am and configure.ac accordingly. Now "configure"
+ needs nothing from the "scripts" directory.
+ Avoid redefining PNG_CONST in pngconf.h
+
+Version 1.4.0beta100 [November 14, 2009]
+ Removed ASM builds from projects/visualc6 and projects/visualc71
+ Removed scripts/makefile.nommx and makefile.vcawin32
+ Revised CMakeLists.txt to account for new location of libpng-config.in
+ and libpng-pc.in
+ Updated INSTALL to reflect removal and relocation of files.
+
+Version 1.4.0beta101 [November 14, 2009]
+ Restored the binary files (*.jpg, *.png, some project files) that were
+ accidentally deleted from the zip and 7z distributions when the xcode
+ project was added.
+
+Version 1.4.0beta102 [November 18, 2009]
+ Added libpng-config.in and libpng-pc.in to the zip and 7z distributions.
+ Fixed a typo in projects/visualc6/pngtest.dsp, introduced in beta100.
Moved descriptions of makefiles and other scripts out of INSTALL into
scripts/README.txt
-
-version 1.2.41rc02 [November 22, 2009]
- Rebuilt the configure scripts with autoconf-2.65
-
-version 1.2.41rc03 [November 25, 2009]
- Disabled the new pedantic warnings about deprecated function use
- and deprecated structure access unless the user defines
- PNG_PEDANTIC_WARNINGS.
+ Updated the copyright year in scripts/pngwin.rc from 2006 to 2009.
+
+Version 1.4.0beta103 [November 21, 2009]
+ Removed obsolete comments about ASM from projects/visualc71/README_zlib.txt
+ Align row_buf on 16-byte boundary in memory.
+ Restored the PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED guard around the call
+ to png_flush() after png_write_IEND(). See 1.4.0beta32, 1.4.0beta50
+ changes above and 1.2.30, 1.2.30rc01 and rc03 in 1.2.41 CHANGES. Someone
+ needs this feature.
+ Make the 'png_jmpbuf' macro expand to a call that records the correct
+ longjmp function as well as returning a pointer to the setjmp
+ jmp_buf buffer, and marked direct access to jmpbuf 'deprecated'.
+ (John Bowler)
+
+Version 1.4.0beta104 [November 22, 2009]
+ Removed png_longjmp_ptr from scripts/*.def and libpng.3
+ Rebuilt configure scripts with autoconf-2.65
+
+Version 1.4.0beta105 [November 25, 2009]
+ Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535()
+ to accomplish alpha premultiplication when
+ PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
+ Changed "/255" to "/255.0" in background calculations to make it clear
+ that the 255 is used as a double.
+
+Version 1.4.0beta106 [November 27, 2009]
+ Removed premultiplied alpha feature.
+
+Version 1.4.0beta107 [December 4, 2009]
+ Updated README
Added "#define PNG_NO_PEDANTIC_WARNINGS" in the libpng source files.
Removed "-DPNG_CONFIGURE_LIBPNG" from the makefiles and projects.
-
-version 1.2.41 and 1.0.51 [December 3, 2009]
- Updated the list of files and made some cosmetic changes in README.
-
-version 1.2.42beta01 [December 4, 2009]
- Removed "#define PNG_NO_ERROR_NUMBERS" that was inadvertently added
- to pngconf.h in version 1.2.41.
Revised scripts/makefile.netbsd, makefile.openbsd, and makefile.sco
to put png.h and pngconf.h in $prefix/include, like the other scripts,
instead of in $prefix/include/libpng. Also revised makefile.sco
- to put them in $prefix/include/libpng12 instead of in
- $prefix/include/libpng/libpng12.
- Removed leftover "-DPNG_CONFIGURE_LIBPNG" from scripts/makefile.darwin
+ to put them in $prefix/include/libpng15 instead of in
+ $prefix/include/libpng/libpng15.
-version 1.2.42beta02 [December 11, 2009]
+Version 1.4.0beta108 [December 11, 2009]
Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
- Relocated png_do_chop() to its original position in pngrtran.c. The
+ Relocated png_do_chop() to its original position in pngrtran.c; the
change in version 1.2.41beta08 caused transparency to be handled wrong
in some 16-bit datastreams (Yusaku Sugai).
-version 1.2.42rc01 [December 17, 2009]
- No changes.
+Version 1.4.0beta109 [December 13, 2009]
+ Added "bit_depth" parameter to the private png_build_gamma_table() function.
+ Pass bit_depth=8 to png_build_gamma_table() when bit_depth is 16 but the
+ PNG_16_TO_8 transform has been set, to avoid unnecessary build of 16-bit
+ tables.
+
+Version 1.4.0rc02 [December 20, 2009]
+ Declared png_cleanup_needed "volatile" in pngread.c and pngwrite.c
-version 1.2.42rc02 [December 22, 2009]
+Version 1.4.0rc03 [December 22, 2009]
Renamed libpng-pc.in back to libpng.pc.in and revised CMakeLists.txt
- (revising changes made in 1.2.41beta17 and 1.2.41rc01)
+ (revising the change in 1.4.0beta99)
-version 1.2.42rc03 [December 25, 2009]
+Version 1.4.0rc04 [December 25, 2009]
Swapped PNG_UNKNOWN_CHUNKS_SUPPORTED and PNG_HANDLE_AS_UNKNOWN_SUPPORTED
in pngset.c to be consistent with other changes in version 1.2.38.
-version 1.2.42rc04 [January 1, 2010]
- Marked png_memcpy_check() and png_memset_check() PNG_DEPRECATED.
- Updated copyright year.
+Version 1.4.0rc05 [December 25, 2009]
+ Changed "libpng-pc.in" to "libpng.pc.in" in configure.ac, configure, and
+ Makefile.in to be consistent with changes in libpng-1.4.0rc03
+
+Version 1.4.0rc06 [December 29, 2009]
+ Reverted the gamma_table changes from libpng-1.4.0beta109.
+ Fixed some indentation errors.
+
+Version 1.4.0rc07 [January 1, 2010]
+ Revised libpng*.txt and libpng.3 about 1.2.x->1.4.x differences.
+ Use png_calloc() instead of png_malloc(); png_memset() in pngrutil.c
+ Update copyright year to 2010.
-version 1.2.42rc05 [January 2, 2010]
+Version 1.4.0rc08 [January 2, 2010]
Avoid deprecated references to png_ptr-io_ptr and png_ptr->error_ptr
in pngtest.c
-version 1.2.42 and 1.0.52 [January 3, 2010]
+Version 1.4.0 [January 3, 2010]
No changes.
-version 1.2.43beta01 [January 27, 2010]
+Version 1.4.1beta01 [January 8, 2010]
Updated CMakeLists.txt for consistent indentation and to avoid an
unclosed if-statement warning (Philip Lowman).
- Removed "#ifdef PNG_1_0_X / #endif" surrounding
- PNG_READ_16_TO_8_SUPPORTED and PNG_READ_GRAY_TO_RGB_SUPPORTED
- in pngconf.h. These were added in libpng-1.2.41beta08 and libpng-1.0.51,
- which introduced a binary incompatibility with libpng-1.0.50.
- Backported new png_decompress_chunk() algorithm from libpng-1.4.1.
-
-version 1.2.43beta02 [February 1, 2010]
- Backported two-pass png_decompress_chunk() algorithm from libpng-1.4.1.
-
-version 1.2.43beta03 [February 6, 2010]
- Backported fast png_push_save_buffer() algorithm from libpng-1.4.1.
- Backported some cosmetic changes from libpng-1.4.1.
-
-version 1.2.43beta04 [February 8, 2010]
- Reverted recent changes to png_push_save-buffer().
- Removed PNGAPI declaration of png_calloc() and png_write_sig() in
- 1ibpng-1.2.X, introduced by mistake in libpng-1.2.41.
- Return allocated "old_buffer" in png_push_save_buffer() before png_error()
- to avoid a potential memory leak.
-
-version 1.2.43beta05 [February 8, 2010]
- Ported rewritten png_decompress_chunk() by John Bowler from libpng-1.4.1.
-
-version 1.0.53rc01 and 1.2.43rc01 [February 18, 2010]
+ Revised Makefile.am and Makefile.in to remove references to Y2KINFO,
+ KNOWNBUG, and libpng.la (Robert Schwebel).
+ Revised the makefiles to install the same files and symbolic
+ links as configure, except for libpng.la and libpng14.la.
+ Make png_set|get_compression_buffer_size() available even when
+ PNG_WRITE_SUPPORTED is not enabled.
+ Revised Makefile.am and Makefile.in to simplify their maintenance.
+ Revised scripts/makefile.linux to install a link to libpng14.so.14.1
+
+Version 1.4.1beta02 [January 9, 2010]
+ Revised the rest of the makefiles to install a link to libpng14.so.14.1
+
+Version 1.4.1beta03 [January 10, 2010]
+ Removed png_set_premultiply_alpha() from scripts/*.def
+
+Version 1.4.1rc01 [January 16, 2010]
No changes.
-version 1.0.53rc02 and 1.2.43rc02 [February 19, 2010]
- Define _ALL_SOURCE in configure.ac, makefile.aix, and CMakeLists.txt
- when using AIX compiler.
-
-version 1.0.53 and 1.2.43 [February 25, 2010]
+Version 1.4.1beta04 [January 23, 2010]
+ Revised png_decompress_chunk() to improve speed and memory usage when
+ decoding large chunks.
+ Added png_set|get_chunk_malloc_max() functions.
+
+Version 1.4.1beta05 [January 26, 2010]
+ Relocated "int k" declaration in pngtest.c to minimize its scope.
+
+Version 1.4.1beta06 [January 28, 2010]
+ Revised png_decompress_chunk() to use a two-pass method suggested by
+ John Bowler.
+
+Version 1.4.1beta07 [February 6, 2010]
+ Folded some long lines in the source files.
+ Added defineable PNG_USER_CHUNK_CACHE_MAX, PNG_USER_CHUNK_MALLOC_MAX,
+ and a PNG_USER_LIMITS_SUPPORTED flag.
+ Eliminated use of png_ptr->irowbytes and reused the slot in png_ptr as
+ png_ptr->png_user_chunk_malloc_max.
+ Revised png_push_save_buffer() to do fewer but larger png_malloc() calls.
+
+Version 1.4.1beta08 [February 6, 2010]
+ Minor cleanup and updating of dates and copyright year.
+
+Version 1.5.0beta01 [February 7, 2010]
+ Moved declaration of png_struct into private pngstruct.h and png_info
+ into pnginfo.h
+
+Version 1.4.1beta09 and 1.5.0beta02 [February 7, 2010]
+ Reverted to original png_push_save_buffer() code.
+
+Version 1.4.1beta10 and 1.5.0beta03 [February 8, 2010]
+ Return allocated "old_buffer" in png_push_save_buffer() before
+ calling png_error(), to avoid a potential memory leak.
+ Updated configure script to use SO number 15.
+
+Version 1.5.0beta04 [February 9, 2010]
+ Removed malformed "incomplete struct declaration" of png_info from png.h
+
+Version 1.5.0beta05 [February 12, 2010]
+ Removed PNG_DEPSTRUCT markup in pngstruct.h and pnginfo.h, and undid the
+ linewrapping that it entailed.
+ Revised comments in pngstruct.h and pnginfo.h and added pointers to
+ the libpng license.
+ Changed PNG_INTERNAL to PNG_EXPOSE_INTERNAL_STRUCTURES
+ Removed the cbuilder5 project, which has not been updated to 1.4.0.
+
+Version 1.4.1beta12 and 1.5.0beta06 [February 14, 2010]
+ Fixed type declaration of png_get_chunk_malloc_max() in pngget.c (Daisuke
+ Nishikawa)
+
+Version 1.5.0beta07 [omitted]
+
+Version 1.5.0beta08 [February 19, 2010]
+ Changed #ifdef PNG_NO_STDIO_SUPPORTED to #ifdef PNG_NO_CONSOLE_IO_SUPPORTED
+ wherever png_snprintf() is used to construct error and warning messages.
+ Noted in scripts/makefile.mingw that it expects to be run under MSYS.
+ Removed obsolete unused MMX-querying support from contrib/gregbook
+ Added exported png_longjmp() function.
+ Removed the AIX redefinition of jmpbuf in png.h
+ Added -D_ALLSOURCE in configure.ac, makefile.aix, and CMakeLists.txt
+ when building on AIX.
+
+Version 1.5.0beta09 [February 19, 2010]
+ Removed -D_ALLSOURCE from configure.ac, makefile.aix, and CMakeLists.txt.
+ Changed the name of png_ptr->jmpbuf to png_ptr->png_jmpbuf in pngstruct.h
+
+Version 1.5.0beta10 [February 25, 2010]
Removed unused gzio.c from contrib/pngminim gather and makefile scripts
-
-version 1.2.44beta01 [June 18, 2010]
+ Removed replacement error handlers from contrib/gregbook. Because of
+ the new png_longjmp() function they are no longer needed.
+
+Version 1.5.0beta11 [March 6, 2010]
+ Removed checking for already-included setjmp.h from pngconf.h
+ Fixed inconsistent indentations and made numerous cosmetic changes.
+ Revised the "SEE ALSO" style of libpng.3, libpngpf.3, and png.5
+
+Version 1.5.0beta12 [March 9, 2010]
+ Moved "#include png.h" inside pngpriv.h and removed "#include png.h" from
+ the source files, along with "#define PNG_EXPOSE_INTERNAL_STRUCTURES"
+ and "#define PNG_NO_PEDANTIC_WARNINGS" (John Bowler).
+ Created new pngdebug.h and moved debug definitions there.
+
+Version 1.5.0beta13 [March 10, 2010]
+ Protect pngstruct.h, pnginfo.h, and pngdebug.h from being included twice.
+ Revise the "#ifdef" blocks in png_inflate() so it will compile when neither
+ PNG_USER_CHUNK_MALLOC_MAX nor PNG_SET_CHUNK_MALLOC_LIMIT_SUPPORTED
+ is defined.
+ Removed unused png_measure_compressed_chunk() from pngpriv.h and libpngpf.3
+ Moved the 'config.h' support from pngconf.h to pngpriv.h
+ Removed PNGAPI from the png_longjmp_ptr typedef.
+ Eliminated dependence of pngtest.c on the private pngdebug.h file.
+ Make all png_debug macros into *unterminated* statements or
+ expressions (i.e. a trailing ';' must always be added) and correct
+ the format statements in various png_debug messages.
+
+Version 1.5.0beta14 [March 14, 2010]
+ Removed direct access to png_ptr->io_ptr from the Windows code in pngtest.c
+ Revised Makefile.am to account for recent additions and replacements.
+ Corrected CE and OS/2 DEF files (scripts/png*def) for symbols removed and
+ added ordinal numbers to the Windows DEF file and corrected the duplicated
+ ordinal numbers on CE symbols that are commented out.
+ Added back in export symbols that can be present in the Windows build but
+ are disabled by default.
+ PNG_EXPORT changed to include an 'ordinal' field for DEF file generation.
+ PNG_CALLBACK added to make callback definitions uniform. PNGAPI split
+ into PNGCAPI (base C form), PNGAPI (exports) and PNGCBAPI (callbacks),
+ and appropriate changes made to all files. Cygwin builds re-hinged to
+ allow procedure call standard changes and to remove the need for the DEF
+ file (fixes build on Cygwin).
+ Enabled 'attribute' warnings that are relevant to library APIs and callbacks.
+ Changed rules for generation of the various symbol files and added a new
+ rule for a DEF file (which is also added to the distribution).
+ Updated the symbol file generation to stop it adding spurious spaces
+ to EOL (coming from preprocessor macro expansion). Added a facility
+ to join tokens in the output and rewrite *.dfn to use this.
+ Eliminated scripts/*.def in favor of libpng.def; updated projects/visualc71
+ and removed scripts/makefile.cygwin.
+ Made PNG_BUILD_DLL safe: it can be set whenever a DLL is being built.
+ Removed the include of sys/types.h - apparently unnecessary now on the
+ platforms on which it happened (all but Mac OS and RISC OS).
+ Moved the Mac OS test into pngpriv.h (the only place it is used.)
+
+Version 1.5.0beta15 [March 17, 2010]
+ Added symbols.chk target to Makefile.am to validate the symbols in png.h
+ against the new DEF file scripts/symbols.def.
+ Changed the default DEF file back to pngwin.def.
+ Removed makefile.mingw.
+ Eliminated PNG_NO_EXTERN and PNG_ALL_EXTERN
+
+Version 1.5.0beta16 [April 1, 2010]
+ Make png_text_struct independent of PNG_iTXt_SUPPORTED, so that
+ fields are initialized in all configurations. The READ/WRITE
+ macros (PNG_(READ|WRITE)_iTXt_SUPPORTED) still function as
+ before to disable code to actually read or write iTXt chunks
+ and iTXt_SUPPORTED can be used to detect presence of either
+ read or write support (but it is probably better to check for
+ the one actually required - read or write.)
+ Combined multiple png_warning() calls for a single error.
+ Restored the macro definition of png_check_sig().
+
+Version 1.5.0beta17 [April 17, 2010]
+ Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+ Documented the fact that png_set_dither() was disabled since libpng-1.4.0.
+ Reenabled png_set_dither() but renamed it to png_set_quantize() to reflect
+ more accurately what it actually does. At the same time, renamed
+ the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros to
+ PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS.
+ Added some "(long)" typecasts to printf calls in png_handle_cHRM().
+ Freeze build-time only configuration in the build.
+ In all prior versions of libpng most configuration options
+ controlled by compiler #defines had to be repeated by the
+ application code that used libpng. This patch changes this
+ so that compilation options that can only be changed at build
+ time are frozen in the build. Options that are compiler
+ dependent (and those that are system dependent) are evaluated
+ each time - pngconf.h holds these. Options that can be changed
+ per-file in the application are in png.h. Frozen options are
+ in the new installed header file pnglibconf.h (John Bowler)
+ Removed the xcode project because it has not been updated to work
+ with libpng-1.5.0.
+ Removed the ability to include optional pngusr.h
+
+Version 1.5.0beta18 [April 17, 2010]
+ Restored the ability to include optional pngusr.h
+ Moved replacements for png_error() and png_warning() from the
+ contrib/pngminim project to pngerror.c, for use when warnings or
+ errors are disabled via PNG_NO_WARN or PNG_NO_ERROR_TEXT, to avoid
+ storing unneeded error/warning text.
+ Updated contrib/pngminim project to work with the new pnglibconf.h
+ Added some PNG_NO_* defines to contrib/pngminim/*/pngusr.h to save space.
+
+Version 1.5.0beta19 [April 24, 2010]
+ Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the functions
+ to read and write ints to be disabled independently of PNG_USE_READ_MACROS,
+ which allows libpng to be built with the functions even though the default
+ is to use the macros - this allows applications to choose at app build
+ time whether or not to use macros (previously impossible because the
+ functions weren't in the default build.)
+ Changed Windows calling convention back to __cdecl for API functions.
+ For Windows/x86 platforms only:
+ __stdcall is no longer needed for Visual Basic, so libpng-1.5.0 uses
+ __cdecl throughout (both API functions and callbacks) on Windows/x86
+ platforms.
+ Replaced visualc6 and visualc71 projects with new vstudio project
+ Relaxed the overly-restrictive permissions of some files.
+
+Version 1.5.0beta20 [April 24, 2010]
+ Relaxed more overly-restrictive permissions of some files.
+
+Version 1.5.0beta21 [April 27, 2010]
+ Removed some unwanted binary bytes and changed CRLF to NEWLINE in the new
+ vstudio project files, and some trivial editing of some files in the
+ scripts directory.
+ Set PNG_NO_READ_BGR, PNG_NO_IO_STATE, and PNG_NO_TIME_RFC1123 in
+ contrib/pngminim/decoder/pngusr.h to make a smaller decoder application.
+
+Version 1.5.0beta22 [April 28, 2010]
+ Fixed dependencies of GET_INT_32 - it does not require READ_INT_FUNCTIONS
+ because it has a macro equivalent.
+ Improved the options.awk script; added an "everything off" option.
+ Revised contrib/pngminim to use the "everything off" option in pngusr.dfa.
+
+Version 1.5.0beta23 [April 29, 2010]
+ Corrected PNG_REMOVED macro to take five arguments.
+ The macro was documented with two arguments (name,ordinal), however
+ the symbol checking .dfn files assumed five arguments. The five
+ argument form seems more useful so it is changed to that.
+ Corrected PNG_UNKNOWN_CHUNKS_SUPPORTED to PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ in gregbook/readpng2.c
+ Corrected protection of png_get_user_transform_ptr. The API declaration in
+ png.h is removed if both READ and WRITE USER_TRANSFORM are turned off
+ but was left defined in pngtrans.c
+ Added logunsupported=1 to cause pnglibconf.h to document disabled options.
+ This makes the installed pnglibconf.h more readable but causes no
+ other change. The intention is that users of libpng will find it
+ easier to understand if an API they need is missing.
+ Include png_reset_zstream() in png.c only when PNG_READ_SUPPORTED is defined.
+ Removed dummy_inflate.c from contrib/pngminim/encoder
+ Removed contrib/pngminim/*/gather.sh; gathering is now done in the makefile.
+
+Version 1.5.0beta24 [May 7, 2010]
+ Use bitwise "&" instead of arithmetic mod in pngrutil.c calculation of the
+ offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
+ Added more blank lines for readability.
+
+Version 1.5.0beta25 [June 18, 2010]
In pngpread.c: png_push_have_row() add check for new_row > height
Removed the now-redundant check for out-of-bounds new_row from example.c
-version 1.2.44beta02 [June 19, 2010]
+Version 1.5.0beta26 [June 18, 2010]
In pngpread.c: png_push_process_row() add check for too many rows.
- Removed the now-redundant check for new_row > height in png_push_have_row().
-version 1.2.44beta03 [June 20, 2010]
- Rewrote png_process_IDAT_data() to consistently treat extra data as warnings
+Version 1.5.0beta27 [June 18, 2010]
+ Removed the check added in beta25 as it is now redundant.
+
+Version 1.5.0beta28 [June 20, 2010]
+ Rewrote png_process_IDAT_data to consistently treat extra data as warnings
and handle end conditions more cleanly.
- Removed the new (beta02) check in png_push_process_row().
+ Removed the new (beta26) check in png_push_process_row().
-version 1.2.44rc01 [June 21, 2010]
- Revised some comments in png_process_IDAT_data().
+Version 1.5.0beta29 [June 21, 2010]
+ Revised scripts/options.awk to work on Sunos (but still doesn't work)
+ Added comment to options.awk and contrib/pngminim/*/makefile to try nawk.
-version 1.2.44rc02 [June 22, 2010]
+Version 1.5.0beta30 [June 22, 2010]
Stop memory leak when reading a malformed sCAL chunk.
-version 1.2.44rc03 [June 23, 2010]
- Revised pngpread.c patch of beta05 to avoid an endless loop.
+Version 1.5.0beta31 [June 26, 2010]
+ Revised pngpread.c patch of beta28 to avoid an endless loop.
+ Removed some trailing blanks.
+
+Version 1.5.0beta32 [June 26, 2010]
+ Removed leftover scripts/options.patch and scripts/options.rej
+
+Version 1.5.0beta33 [July 6, 3010]
+ Made FIXED and FLOATING options consistent in the APIs they enable and
+ disable. Corrected scripts/options.awk to handle both command line
+ options and options specified in the .dfa files.
+ Changed char *msg to PNG_CONST char *msg in pngrutil.c
+ Make png_set_sRGB_gAMA_and_cHRM set values using either the fixed or
+ floating point APIs, but not both.
+ Reversed patch to remove error handler when the jmp_buf is stored in the
+ main program structure, not the png_struct.
+ The error handler is needed because the default handler in libpng will
+ always use the jmp_buf in the library control structure; this is never
+ set. The gregbook code is a useful example because, even though it
+ uses setjmp/longjmp, it shows how error handling can be implemented
+ using control mechanisms not directly supported by libpng. The
+ technique will work correctly with mechanisms such as Microsoft
+ Structure Exceptions or C++ exceptions (compiler willing - note that gcc
+ does not by default support interworking of C and C++ error handling.)
+ Reverted changes to call png_longjmp in contrib/gregbook where it is not
+ appropriate. If mainprog->jmpbuf is used by setjmp, then png_longjmp
+ cannot be used.
+ Changed "extern PNG_EXPORT" to "PNG_EXPORT" in png.h (Jan Nijtmans)
+ Changed "extern" to "PNG_EXTERN" in pngpriv.h (except for the 'extern "C" {')
+
+Version 1.5.0beta34 [July 12, 2010]
+ Put #ifndef PNG_EXTERN, #endif around the define PNG_EXTERN in pngpriv.h
+
+Version 1.5.0beta35 [July 24, 2010]
+ Removed some newly-added TAB characters.
+ Added -DNO_PNG_SNPRINTF to CFLAGS in scripts/makefile.dj2
+ Moved the definition of png_snprintf() outside of the enclosing
+ #ifdef blocks in pngconf.h
+
+Version 1.5.0beta36 [July 29, 2010]
+ Patches by John Bowler:
+ Fixed point APIs are now supported throughout (no missing APIs).
+ Internal fixed point arithmetic support exists for all internal floating
+ point operations.
+ sCAL validates the floating point strings it is passed.
+ Safe, albeit rudimentary, Watcom support is provided by PNG_API_RULE==2
+ Two new APIs exist to get the number of passes without turning on the
+ PNG_INTERLACE transform and to get the number of rows in the current
+ pass.
+ A new test program, pngvalid.c, validates the gamma code.
+ Errors in the 16-bit gamma correction (overflows) have been corrected.
+ cHRM chunk testing is done consistently (previously the floating point
+ API bypassed it, because the test really didn't work on FP, now the test
+ is performed on the actual values to be stored in the PNG file so it
+ works in the FP case too.)
+ Most floating point APIs now simply call the fixed point APIs after
+ converting the values to the fixed point form used in the PNG file.
+ The standard headers no longer include zlib.h, which is currently only
+ required for pngstruct.h and can therefore be internal.
+ Revised png_get_int_32 to undo the PNG two's complement representation of
+ negative numbers.
+
+Version 1.5.0beta37 [July 30, 2010]
+ Added a typecast in png_get_int_32() in png.h and pngrutil.h to avoid
+ a compiler warning.
+ Replaced oFFs 0,0 with oFFs -10,20 in pngtest.png
+
+Version 1.5.0beta38 [July 31, 2010]
+ Implemented remaining "_fixed" functions.
+ Corrected a number of recently introduced warnings mostly resulting from
+ safe but uncast assignments to shorter integers. Also added a zlib
+ VStudio release library project because the latest zlib Official Windows
+ build does not include such a thing.
+ Revised png_get_int_16() to be similar to png_get_int_32().
+ Restored projects/visualc71.
+
+Version 1.5.0beta39 [August 2, 2010]
+ VisualC/GCC warning fixes, VisualC build fixes
+ The changes include support for function attributes in VC in addition to
+ those already present in GCC - necessary because without these some
+ warnings are unavoidable. Fixes include signed/unsigned fixes in
+ pngvalid and checks with gcc -Wall -Wextra -Wunused.
+ VC requires function attributes on function definitions as well as
+ declarations, PNG_FUNCTION has been added to enable this and the
+ relevant function definitions changed.
+
+Version 1.5.0beta40 [August 6, 2010]
+ Correct use of _WINDOWS_ in pngconf.h
+ Removed png_mem_ #defines; they are no longer used.
+ Added the sRGB chunk to pngtest.png
+
+Version 1.5.0beta41 [August 11, 2010]
+ Added the cHRM chunk to pngtest.png
+ Don't try to use version-script with cygwin/mingw.
+ Revised contrib/gregbook to work under cygwin/mingw.
+
+Version 1.5.0beta42 [August 18, 2010]
+ Add .dll.a to the list of extensions to be symlinked by Makefile.am (Yaakov)
+ Made all API functions that have const arguments and constant string
+ literal pointers declare them (John Bowler).
+
+Version 1.5.0beta43 [August 20, 2010]
+ Removed spurious tabs, shorten long lines (no source change)
+ Also added scripts/chkfmt to validate the format of all the files that can
+ reasonably be validated (it is suggested to run "make distclean" before
+ checking, because some machine generated files have long lines.)
+ Reformatted the CHANGES file to be more consistent throughout.
+ Made changes to address various issues identified by GCC, mostly
+ signed/unsigned and shortening problems on assignment but also a few
+ difficult to optimize (for GCC) loops.
+ Fixed non-GCC fixed point builds. In png.c a declaration was misplaced
+ in an earlier update. Fixed to declare the auto variables at the head.
+ Use cexcept.h in pngvalid.c.
+
+Version 1.5.0beta44 [August 24, 2010]
+ Updated CMakeLists.txt to use CMAKE_INSTALL_LIBDIR variable; useful for
+ installing libpng in /usr/lib64 (Funda Wang).
+ Revised CMakeLists.txt to put the man pages in share/man/man* not man/man*
+ Revised CMakeLists.txt to make symlinks instead of copies when installing.
+ Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
+ Implemented memory checks within pngvalid
+ Reformatted/rearranged pngvalid.c to assist use of progressive reader.
+ Check interlaced images in pngvalid
+ Clarified pngusr.h comments in pnglibconf.dfa
+ Simplified the pngvalid error-handling code now that cexcept.h is in place.
+ Implemented progressive reader in pngvalid.c for standard tests
+ Implemented progressive read in pngvalid.c gamma tests
+ Turn on progressive reader in pngvalid.c by default and tidy code.
+
+Version 1.5.0beta45 [August 26, 2010]
+ Added an explicit make step to projects/vstudio for pnglibconf.h
+ Also corrected zlib.vcxproj into which Visual Studio had introduced
+ what it calls an "authoring error". The change to make pnglibconf.h
+ simply copies the file; in the future it may actually generate the
+ file from scripts/pnglibconf.dfa as the other build systems do.
+ Changed pngvalid to work when floating point APIs are disabled
+ Renamed the prebuilt scripts/pnglibconf.h to scripts/pnglibconf.h.prebuilt
+ Supply default values for PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX
+ in pngpriv.h in case the user neglected to define them in their pngusr.h
+
+Version 1.5.0beta46 [August 28, 2010]
+ Added new private header files to libpng_sources in CMakeLists.txt
+ Added PNG_READ_16BIT, PNG_WRITE_16BIT, and PNG_16BIT options.
+ Added reference to scripts/pnglibconf.h.prebuilt in the visualc71 project.
+
+Version 1.5.0beta47 [September 11, 2010]
+ Fixed a number of problems with 64-bit compilation reported by Visual
+ Studio 2010 (John Bowler).
+
+Version 1.5.0beta48 [October 4, 2010]
+ Updated CMakeLists.txt (Philip Lowman).
+ Revised autogen.sh to recognize and use $AUTOCONF, $AUTOMAKE, $AUTOHEADER,
+ $AUTOPOINT, $ACLOCAL and $LIBTOOLIZE
+ Fixed problem with symbols creation in Makefile.am which was assuming that
+ all versions of ccp write to standard output by default (Martin Banky). The
+ bug was introduced in libpng-1.2.9beta5.
+ Removed unused mkinstalldirs.
+
+Version 1.5.0beta49 [October 8, 2010]
+ Undid Makefile.am revision of 1.5.0beta48.
+
+Version 1.5.0beta50 [October 14, 2010]
+ Revised Makefile.in to account for mkinstalldirs being removed.
+ Added some "(unsigned long)" typecasts in printf statements in pngvalid.c.
+ Suppressed a compiler warning in png_handle_sPLT().
+ Check for out-of-range text compression mode in png_set_text().
+
+Version 1.5.0beta51 [October 15, 2010]
+ Changed embedded dates to "(PENDING RELEASE) in beta releases (and future
+ rc releases) to minimize the difference between releases.
+
+Version 1.5.0beta52 [October 16, 2010]
+ Restored some of the embedded dates (in png.h, png.c, documentation, etc.)
+
+Version 1.5.0beta53 [October 18, 2010]
+ Updated INSTALL to mention using "make maintainer-clean" and to remove
+ obsolete statement about a custom ltmain.sh
+ Disabled "color-tests" by default in Makefile.am so it will work with
+ automake versions earlier than 1.11.1
+ Use document name "libpng-manual.txt" instead of "libpng-<version>.txt"
+ to simplify version differences.
+ Removed obsolete remarks about setjmp handling from INSTALL.
+ Revised and renamed the typedef in png.h and png.c that was designed
+ to catch library and header mismatch.
+
+Version 1.5.0beta54 [November 10, 2010]
+ Require 48 bytes, not 64 bytes, for big_row_buf in overflow checks.
+ Used a consistent structure for the pngget.c functions.
+
+Version 1.5.0beta55 [November 21, 2010]
+ Revised png_get_uint_32, png_get_int_32, png_get_uint_16 (Cosmin)
+ Moved reading of file signature into png_read_sig (Cosmin)
+ Fixed atomicity of chunk header serialization (Cosmin)
+ Added test for io_state in pngtest.c (Cosmin)
+ Added "#!/bin/sh" at the top of contrib/pngminim/*/gather.sh scripts.
+ Changes to remove gcc warnings (John Bowler)
+ Certain optional gcc warning flags resulted in warnings in libpng code.
+ With these changes only -Wconversion and -Wcast-qual cannot be turned on.
+ Changes are trivial rearrangements of code. -Wconversion is not possible
+ for pngrutil.c (because of the widespread use of += et al on variables
+ smaller than (int) or (unsigned int)) and -Wcast-qual is not possible
+ with pngwio.c and pngwutil.c because the 'write' callback and zlib
+ compression both fail to declare their input buffers with 'const'.
+
+Version 1.5.0beta56 [December 7, 2010]
+ Added the private PNG_UNUSED() macro definition in pngpriv.h.
+ Added some commentary about PNG_EXPORT in png.h and pngconf.h
+ Revised PNG_EXPORT() macro and added PNG_EXPORTA() macro, with the
+ objective of simplifying and improving the cosmetic appearance of png.h.
+ Fixed some incorrect "=" macro names in pnglibconf.dfa
+ Included documentation of changes in 1.5.0 from 1.4.x in libpng-manual.txt
+
+Version 1.5.0beta57 [December 9, 2010]
+ Documented the pngvalid gamma error summary with additional comments and
+ print statements.
+ Improved missing symbol handling in checksym.awk; symbols missing in both
+ the old and new files can now be optionally ignored, treated as errors
+ or warnings.
+ Removed references to pngvcrd.c and pnggccrd.c from the vstudio project.
+ Updated "libpng14" to "libpng15" in the visualc71 project.
+ Enabled the strip16 tests in pngvalid.`
+ Don't display test results (except PASS/FAIL) when running "make test".
+ Instead put them in pngtest-log.txt
+ Added "--with-zprefix=<string>" to configure.ac
+ Updated the prebuilt configuration files to autoconf version 2.68
+
+Version 1.5.0beta58 [December 19, 2010]
+ Fixed interlace image handling and add test cases (John Bowler)
+ Fixed the clean rule in Makefile.am to remove pngtest-log.txt
+ Made minor changes to work around warnings in gcc 3.4
+
+Version 1.5.0rc01 [December 27, 2010]
+ No changes.
+
+Version 1.5.0rc02 [December 27, 2010]
+ Eliminated references to the scripts/*.def files in project/visualc71.
+
+Version 1.5.0rc03 [December 28, 2010]
+ Eliminated scripts/*.def and revised Makefile.am accordingly
+
+Version 1.5.0rc04 [December 29, 2010]
+ Fixed bug in background transformation handling in pngrtran.c (it was
+ looking for the flag in png_ptr->transformations instead of in
+ png_ptr->flags) (David Raymond).
+
+Version 1.5.0rc05 [December 31, 2010]
+ Fixed typo in a comment in CMakeLists.txt (libpng14 => libpng15) (Cosmin)
+
+Version 1.5.0rc06 [January 4, 2011]
+ Changed the new configure option "zprefix=string" to "zlib-prefix=string"
+
+Version 1.5.0rc07 [January 4, 2011]
+ Updated copyright year.
+
+Version 1.5.0 [January 6, 2011]
+ No changes.
+
+version 1.5.1beta01 [January 8, 2011]
+ Added description of png_set_crc_action() to the manual.
+ Added a note in the manual that the type of the iCCP profile was changed
+ from png_charpp to png_bytepp in png_get_iCCP(). This change happened
+ in version 1.5.0beta36 but is not noted in the CHANGES. Similarly,
+ it was changed from png_charpp to png_const_bytepp in png_set_iCCP().
+ Ensure that png_rgb_to_gray ignores palette mapped images, if libpng
+ internally happens to call it with one, and fixed a failure to handle
+ palette mapped images correctly. This fixes CVE-2690.
+
+Version 1.5.1beta02 [January 14, 2011]
+ Fixed a bug in handling of interlaced images (bero at arklinux.org).
+ Updated CMakeLists.txt (Clifford Yapp)
+
+Version 1.5.1beta03 [January 14, 2011]
+ Fixed typecasting of some png_debug() statements (Cosmin)
+
+Version 1.5.1beta04 [January 16, 2011]
+ Updated documentation of png_set|get_tRNS() (Thomas Klausner).
+ Mentioned in the documentation that applications must #include "zlib.h"
+ if they need access to anything in zlib.h, and that a number of
+ macros such as png_memset() are no longer accessible by applications.
+ Corrected pngvalid gamma test "sample" function to access all of the color
+ samples of each pixel, instead of sampling the red channel three times.
+ Prefixed variable names index, div, exp, gamma with "png_" to avoid "shadow"
+ warnings, and (mistakenly) changed png_exp() to exp().
+
+Version 1.5.1beta05 [January 16, 2011]
+ Changed variable names png_index, png_div, png_exp, and png_gamma to
+ char_index, divisor, exp_b10, and gamma_val, respectively, and
+ changed exp() back to png_exp().
+
+Version 1.5.1beta06 [January 20, 2011]
+ Prevent png_push_crc_skip() from hanging while reading an unknown chunk
+ or an over-large compressed zTXt chunk with the progressive reader.
+ Eliminated more GCC "shadow" warnings.
+ Revised png_fixed() in png.c to avoid compiler warning about reaching the
+ end without returning anything.
+
+Version 1.5.1beta07 [January 22, 2011]
+ In the manual, describe the png_get_IHDR() arguments in the correct order.
+ Added const_png_structp and const_png_infop types, and used them in
+ prototypes for most png_get_*() functions.
+
+Version 1.5.1beta08 [January 23, 2011]
+ Added png_get_io_chunk_type() and deprecated png_get_io_chunk_name()
+ Added synopses for the IO_STATE functions and other missing synopses
+ to the manual. Removed the synopses from libpngpf.3 because they
+ were out of date and no longer useful. Better information can be
+ obtained by reading the prototypes and comments in pngpriv.h
+ Attempted to fix cpp on Solaris with S. Studio 12 cc, fix build
+ Added a make macro DFNCPP that is a CPP that will accept the tokens in
+ a .dfn file and adds configure stuff to test for such a CPP. ./configure
+ should fail if one is not available.
+ Corrected const_png_ in png.h to png_const_ to avoid polluting the namespace.
+ Added png_get_current_row_number and png_get_current_pass_number for the
+ benefit of the user transform callback.
+ Added png_process_data_pause and png_process_data_skip for the benefit of
+ progressive readers that need to stop data processing or want to optimize
+ skipping of unread data (e.g., if the reader marks a chunk to be skipped.)
+
+Version 1.5.1beta09 [January 24, 2011]
+ Enhanced pngvalid, corrected an error in gray_to_rgb, corrected doc error.
+ pngvalid contains tests of transforms, which tests are currently disabled
+ because they are incompletely tested. gray_to_rgb was failing to expand
+ the bit depth for smaller bit depth images; this seems to be a long
+ standing error and resulted, apparently, in invalid output
+ (CVE-2011-0408, CERT VU#643140). The documentation did not accurately
+ describe what libpng really does when converting RGB to gray.
+
+Version 1.5.1beta10 [January 27, 2010]
+ Fixed incorrect examples of callback prototypes in the manual, that were
+ introduced in libpng-1.0.0.
+ In addition the order of the png_get_uint macros with respect to the
+ relevant function definitions has been reversed. This helps the
+ preprocessing of the symbol files be more robust. Furthermore, the
+ symbol file preprocessing now uses -DPNG_NO_USE_READ_MACROS even when
+ the library may actually be built with PNG_USE_READ_MACROS; this stops
+ the read macros interfering with the symbol file format.
+ Made the manual, synopses, and function prototypes use the function
+ argument names file_gamma, int_file_gamma, and srgb_intent consistently.
+
+Version 1.5.1beta11 [January 28, 2011]
+ Changed PNG_UNUSED from "param=param;" to "{if(param){}}".
+ Corrected local variable type in new API png_process_data_skip()
+ The type was self-evidently incorrect but only causes problems on 64-bit
+ architectures.
+ Added transform tests to pngvalid and simplified the arguments.
+
+Version 1.5.1rc01 [January 29, 2011]
+ No changes.
+
+Version 1.5.1rc02 [January 31, 2011]
+ Added a request in the manual that applications do not use "png_" or
+ "PNG_" to begin any of their own symbols.
+ Changed PNG_UNUSED to "(void)param;" and updated the commentary in pngpriv.h
+
+Version 1.5.1 [February 3, 2011]
+ No changes.
+
+Version 1.5.2beta01 [February 13, 2011]
+ More -Wshadow fixes for older gcc compilers. Older gcc versions apparently
+ check formal parameters names in function declarations (as well as
+ definitions) to see if they match a name in the global namespace.
+ Revised PNG_EXPORTA macro to not use an empty parameter, to accommodate the
+ old VisualC++ preprocessor.
+ Turned on interlace handling in png_read_png().
+ Fixed gcc pedantic warnings.
+ Handle longjmp in Cygwin.
+ Fixed png_get_current_row_number() in the interlaced case.
+ Cleaned up ALPHA flags and transformations.
+ Implemented expansion to 16 bits.
+
+Version 1.5.2beta02 [February 19, 2011]
+ Fixed mistake in the descriptions of user read_transform and write_transform
+ function prototypes in the manual. The row_info struct is png_row_infop.
+ Reverted png_get_current_row_number() to previous (1.5.2beta01) behavior.
+ Corrected png_get_current_row_number documentation
+ Fixed the read/write row callback documentation.
+ This documents the current behavior, where the callback is called after
+ every row with information pertaining to the next row.
+
+Version 1.5.2beta03 [March 3, 2011]
+ Fixed scripts/makefile.vcwin32
+ Updated contrib/pngsuite/README to add the word "modify".
+ Define PNG_ALLOCATED to blank when _MSC_VER<1300.
+
+Version 1.5.2rc01 [March 19, 2011]
+ Define remaining attributes to blank when MSC_VER<1300.
+ ifdef out mask arrays in pngread.c when interlacing is not supported.
+
+Version 1.5.2rc02 [March 22, 2011]
+ Added a hint to try CPP=/bin/cpp if "cpp -E" fails in scripts/pnglibconf.mak
+ and in contrib/pngminim/*/makefile, eg., on SunOS 5.10, and removed "strip"
+ from the makefiles.
+ Fixed a bug (present since libpng-1.0.7) that makes png_handle_sPLT() fail
+ to compile when PNG_NO_POINTER_INDEXING is defined (Chubanov Kirill)
+
+Version 1.5.2rc03 [March 24, 2011]
+ Don't include standard header files in png.h while building the symbol table,
+ to avoid cpp failure on SunOS (introduced PNG_BUILDING_SYMBOL_TABLE macro).
+
+Version 1.5.2 [March 31, 2011]
+ No changes.
+
+Version 1.5.3beta01 [April 1, 2011]
+ Re-initialize the zlib compressor before compressing non-IDAT chunks.
+ Added API functions (png_set_text_compression_level() and four others) to
+ set parameters for zlib compression of non-IDAT chunks.
+
+Version 1.5.3beta02 [April 3, 2011]
+ Updated scripts/symbols.def with new API functions.
+ Only compile the new zlib re-initializing code when text or iCCP is
+ supported, using PNG_WRITE_COMPRESSED_TEXT_SUPPORTED macro.
+ Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
+ Optimize the zlib CMF byte in non-IDAT compressed chunks
+
+Version 1.5.3beta03 [April 16, 2011]
+ Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+ snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+ than __STDC__ (John Bowler).
+ Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+ the compiler that a user supplied callback (the error handler) does not
+ return, yet there is no guarantee in practice that the application code
+ will correctly implement the error handler because the compiler only
+ issues a warning if there is a mistake (John Bowler).
+ Removed the no-longer-used PNG_DEPSTRUCT macro.
+ Updated the zlib version to 1.2.5 in the VStudio project.
+ Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+ pngwutil.c (John Bowler).
+ Fixed bug with stripping the filler or alpha channel when writing, that
+ was introduced in libpng-1.5.2beta01 (bug report by Andrew Church).
+
+Version 1.5.3beta04 [April 27, 2011]
+ Updated pngtest.png with the new zlib CMF optimization.
+ Cleaned up conditional compilation code and of background/gamma handling
+ Internal changes only except a new option to avoid compiling the
+ png_build_grayscale_palette API (which is not used at all internally.)
+ The main change is to move the transform tests (READ_TRANSFORMS,
+ WRITE_TRANSFORMS) up one level to the caller of the APIs. This avoids
+ calls to spurious functions if all transforms are disabled and slightly
+ simplifies those functions. Pngvalid modified to handle this.
+ A minor change is to stop the strip_16 and expand_16 interfaces from
+ disabling each other; this allows the future alpha premultiplication
+ code to use 16-bit intermediate values while still producing 8-bit output.
+ png_do_background and png_do_gamma have been simplified to take a single
+ pointer to the png_struct rather than pointers to every item required
+ from the png_struct. This makes no practical difference to the internal
+ code.
+ A serious bug in the pngvalid internal routine 'standard_display_init' has
+ been fixed - this failed to initialize the red channel and accidentally
+ initialized the alpha channel twice.
+ Changed png_struct jmp_buf member name from png_jmpbuf to tmp_jmpbuf to
+ avoid a possible clash with the png_jmpbuf macro on some platforms.
+
+Version 1.5.3beta05 [May 6, 2011]
+ Added the "_POSIX_SOURCE" feature test macro to ensure libpng sees the
+ correct API. _POSIX_SOURCE is defined in pngpriv.h, pngtest.c and
+ pngvalid.c to ensure that POSIX conformant systems disable non-POSIX APIs.
+ Removed png_snprintf and added formatted warning messages. This change adds
+ internal APIs to allow png_warning messages to have parameters without
+ requiring the host OS to implement snprintf. As a side effect the
+ dependency of the tIME-supporting RFC1132 code on stdio is removed and
+ PNG_NO_WARNINGS does actually work now.
+ Pass "" instead of '\0' to png_default_error() in png_err(). This mistake
+ was introduced in libpng-1.2.20beta01. This fixes CVE-2011-2691.
+ Added PNG_WRITE_OPTIMIZE_CMF_SUPPORTED macro to make the zlib "CMF" byte
+ optimization configurable.
+ IDAT compression failed if preceded by a compressed text chunk (bug
+ introduced in libpng-1.5.3beta01-02). This was because the attempt to
+ reset the zlib stream in png_write_IDAT happened after the first IDAT
+ chunk had been deflated - much too late. In this change internal
+ functions were added to claim/release the z_stream and, hopefully, make
+ the code more robust. Also deflateEnd checking is added - previously
+ libpng would ignore an error at the end of the stream.
+
+Version 1.5.3beta06 [May 8, 2011]
+ Removed the -D_ALL_SOURCE from definitions for AIX in CMakeLists.txt
+ Implemented premultiplied alpha support: png_set_alpha_mode API
+
+Version 1.5.3beta07 [May 11, 2011]
+ Added expand_16 support to the high level interface.
+ Added named value and 'flag' gamma support to png_set_gamma. Made a minor
+ change from the previous (unreleased) ABI/API to hide the exact value used
+ for Macs - it's not a good idea to embed this in the ABI!
+ Moved macro definitions for PNG_HAVE_IHDR, PNG_HAVE_PLTE, and PNG_AFTER_IDAT
+ from pngpriv.h to png.h because they must be visible to applications
+ that call png_set_unknown_chunks().
+ Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
+ before IDAT.
+
+Version 1.5.3beta08 [May 16, 2011]
+ Improved "pngvalid --speed" to exclude more of pngvalid from the time.
+ Documented png_set_alpha_mode(), other changes in libpng.3/libpng-manual.txt
+ The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
+ parameters are supplied by the caller), while in the absence of cHRM
+ sRGB/Rec 709 values are still used. This introduced a divide-by-zero
+ bug in png_handle_cHRM().
+ The bKGD chunk no longer overwrites the background value set by
+ png_set_background(), allowing the latter to be used before the file
+ header is read. It never performed any useful function to override
+ the default anyway.
+ Added memory overwrite and palette image checks to pngvalid.c
+ Previously palette image code was poorly checked. Since the transformation
+ code has a special palette path in most cases this was a severe weakness.
+ Minor cleanup and some extra checking in pngrutil.c and pngrtran.c. When
+ expanding an indexed image, always expand to RGBA if transparency is
+ present.
+
+Version 1.5.3beta09 [May 17, 2011]
+ Reversed earlier 1.5.3 change of transformation order; move png_expand_16
+ back where it was. The change doesn't work because it requires 16-bit
+ gamma tables when the code only generates 8-bit ones. This fails
+ silently; the libpng code just doesn't do any gamma correction. Moving
+ the tests back leaves the old, inaccurate, 8-bit gamma calculations, but
+ these are clearly better than none!
+
+Version 1.5.3beta10 [May 20, 2011]
+
+ png_set_background() and png_expand_16() did not work together correctly.
+ This problem is present in 1.5.2; if png_set_background is called with
+ need_expand false and the matching 16 bit color libpng erroneously just
+ treats it as an 8-bit color because of where png_do_expand_16 is in the
+ transform list. This simple fix reduces the supplied colour to 8-bits,
+ so it gets smashed, but this is better than the current behavior.
+ Added tests for expand16, more fixes for palette image tests to pngvalid.
+ Corrects the code for palette image tests and disables attempts to
+ validate palette colors.
+
+Version 1.5.3rc01 [June 3, 2011]
+ No changes.
+
+Version 1.5.3rc02 [June 8, 2011]
+ Fixed uninitialized memory read in png_format_buffer() (Bug report by
+ Frank Busse, CVE-2011-2501, related to CVE-2004-0421).
+
+Version 1.5.3beta11 [June 11, 2011]
+ Fixed png_handle_sCAL which is broken in 1.5. This fixes CVE 2011-2692.
+ Added sCAL to pngtest.png
+ Revised documentation about png_set_user_limits() to say that it also affects
+ png writing.
+ Revised handling of png_set_user_limits() so that it can increase the
+ limit beyond the PNG_USER_WIDTH|HEIGHT_MAX; previously it could only
+ reduce it.
+ Make the 16-to-8 scaling accurate. Dividing by 256 with no rounding is
+ wrong (high by one) 25% of the time. Dividing by 257 with rounding is
+ wrong in 128 out of 65536 cases. Getting the right answer all the time
+ without division is easy.
+ Added "_SUPPORTED" to the PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION macro.
+ Added projects/owatcom, an IDE project for OpenWatcom to replace
+ scripts/makefile.watcom. This project works with OpenWatcom 1.9. The
+ IDE autogenerates appropriate makefiles (libpng.mk) for batch processing.
+ The project is configurable, unlike the Visual Studio project, so long
+ as the developer has an awk.
+ Changed png_set_gAMA to limit the gamma value range so that the inverse
+ of the stored value cannot overflow the fixed point representation,
+ and changed other things OpenWatcom warns about.
+ Revised pngvalid.c to test PNG_ALPHA_MODE_SUPPORTED correctly. This allows
+ pngvalid to build when ALPHA_MODE is not supported, which is required if
+ it is to build on libpng 1.4.
+ Removed string/memory macros that are no longer used and are not
+ necessarily fully supportable, particularly png_strncpy and png_snprintf.
+ Added log option to pngvalid.c and attempted to improve gamma messages.
+
+Version 1.5.3 [omitted]
+ People found the presence of a beta release following an rc release
+ to be confusing; therefore we bump the version to libpng-1.5.4beta01
+ and there will be no libpng-1.5.3 release.
+
+Version 1.5.4beta01 [June 14, 2011]
+ Made it possible to undefine PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+ to get the same (inaccurate) output as libpng-1.5.2 and earlier.
+ Moved definitions of PNG_HAVE_IHDR, PNG_AFTER_IDAT, and PNG_HAVE_PLTE
+ outside of an unknown-chunk block in png.h because they are also
+ needed for other uses.
+
+Version 1.5.4beta02 [June 14, 2011]
+ Fixed and clarified LEGACY 16-to-8 scaling code.
+ Added png_set_chop_16() API, to match inaccurate results from previous
+ libpng versions.
+ Removed the ACCURATE and LEGACY options (they are no longer useable)
+ Use the old scaling method for background if png_set_chop_16() was
+ called.
+ Made png_set_chop_16() API removeable by disabling PNG_CHOP_16_TO_8_SUPPORTED
+
+Version 1.5.4beta03 [June 15, 2011]
+ Fixed a problem in png_do_expand_palette() exposed by optimization in
+ 1.5.3beta06
+ Also removed a spurious and confusing "trans" member ("trans") from png_info.
+ The palette expand optimization prevented expansion to an intermediate RGBA
+ form if tRNS was present but alpha was marked to be stripped; this exposed
+ a check for tRNS in png_do_expand_palette() which is inconsistent with the
+ code elsewhere in libpng.
+ Correction to the expand_16 code; removed extra instance of
+ png_set_scale_16_to_8 from pngpriv.h
+
+Version 1.5.4beta04 [June 16, 2011]
+ Added a missing "#ifdef PNG_READ_BACKGROUND_SUPPORTED/#endif" in pngrtran.c
+ Added PNG_TRANSFORM_CHOP_16 to the high-level read transforms.
+ Made PNG_READ_16_TO_8_ACCURATE_SCALE configurable again. If this is
+ not enabled, png_set_strip_16() and png_do_scale_16_to_8() aren't built.
+ Revised contrib/visupng, gregbook, and pngminim to demonstrate chop_16_to_8
+
+Version 1.5.4beta05 [June 16, 2011]
+ Renamed png_set_strip_16() to png_set_scale_16() and renamed
+ png_set_chop_16() to png_set_strip(16) in an attempt to minimize the
+ behavior changes between libpng14 and libpng15.
+
+Version 1.5.4beta06 [June 18, 2011]
+ Fixed new bug that was causing both strip_16 and scale_16 to be applied.
+
+Version 1.5.4beta07 [June 19, 2011]
+ Fixed pngvalid, simplified macros, added checking for 0 in sCAL.
+ The ACCURATE scale macro is no longer defined in 1.5 - call the
+ png_scale_16_to_8 API. Made sure that PNG_READ_16_TO_8 is still defined
+ if the png_strip_16_to_8 API is present. png_check_fp_number now
+ maintains some state so that positive, negative and zero values are
+ identified. sCAL uses these to be strictly spec conformant.
+
+Version 1.5.4beta08 [June 23, 2011]
+ Fixed pngvalid if ACCURATE_SCALE is defined.
+ Updated scripts/pnglibconf.h.prebuilt.
+
+Version 1.5.4rc01 [June 30, 2011]
+ Define PNG_ALLOCATED to "restrict" only if MSC_VER >= 1400.
+
+Version 1.5.4 [July 7, 2011]
+ No changes.
-version 1.2.44 [June 26, 2010]
- Updated some of the "last changed" dates.
+Version 1.5.5beta01 [July 13, 2011]
+ Fixed some typos and made other minor changes in the manual.
+ Updated contrib/pngminus/makefile.std (Samuli Souminen)
+
+Version 1.5.5beta02 [July 14, 2011]
+ Revised Makefile.am and Makefile.in to look in the right directory for
+ pnglibconf.h.prebuilt
+
+Version 1.5.5beta03 [July 27, 2011]
+ Enabled compilation with g++ compiler. This compiler does not recognize
+ the file extension, so it always compiles with C++ rules. Made minor
+ changes to pngrutil.c to cast results where C++ expects it but C does not.
+ Minor editing of libpng.3 and libpng-manual.txt.
+
+Version 1.5.5beta04 [July 29, 2011]
+ Revised CMakeLists.txt (Clifford Yapp)
+ Updated commentary about the png_rgb_to_gray() default coefficients
+ in the manual and in pngrtran.c
+
+Version 1.5.5beta05 [August 17, 2011]
+ Prevent unexpected API exports from non-libpng DLLs on Windows. The "_DLL"
+ is removed from the test of whether a DLL is being built (this erroneously
+ caused the libpng APIs to be marked as DLL exports in static builds under
+ Microsoft Visual Studio). Almost all of the libpng building configuration
+ is moved from pngconf.h to pngpriv.h, but PNG_DLL_EXPORT remains in
+ pngconf.h, though, so that it is colocated with the import definition (it
+ is no longer used anywhere in the installed headers). The VStudio project
+ definitions have been cleaned up: "_USRDLL" has been removed from the
+ static library builds (this was incorrect), and PNG_USE_DLL has been added
+ to pngvalid to test the functionality (pngtest does not supply it,
+ deliberately). The spurious "_EXPORTS" has been removed from the
+ libpng build (all these errors were a result of copy/paste between project
+ configurations.)
+ Added new types and internal functions for CIE RGB end point handling to
+ pngpriv.h (functions yet to be implemented).
+
+Version 1.5.5beta06 [August 26, 2011]
+ Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set in CMakeLists.txt
+ (Clifford Yap)
+ Fixes to rgb_to_gray and cHRM XYZ APIs (John Bowler):
+ The rgb_to_gray code had errors when combined with gamma correction.
+ Some pixels were treated as true grey when they weren't and such pixels
+ and true grey ones were not gamma corrected (the original value of the
+ red component was used instead). APIs to get and set cHRM using color
+ space end points have been added and the rgb_to_gray code that defaults
+ based on cHRM, and the divide-by-zero bug in png_handle_cHRM (CERT
+ VU#477046, CVE-2011-3328, introduced in 1.5.4) have been corrected.
+ A considerable number of tests has been added to pngvalid for the
+ rgb_to_gray transform.
+ Arithmetic errors in rgb_to_gray whereby the calculated gray value was
+ truncated to the bit depth rather than rounded have been fixed except in
+ the 8-bit non-gamma-corrected case (where consistency seems more important
+ than correctness.) The code still has considerable inaccuracies in the
+ 8-bit case because 8-bit linear arithmetic is used.
+
+Version 1.5.5beta07 [September 7, 2011]
+ Added "$(ARCH)" option to makefile.darwin
+ Added SunOS support to configure.ac and Makefile.am
+ Changed png_chunk_benign_error() to png_warning() in png.c, in
+ png_XYZ_from_xy_checked().
+
+Version 1.5.5beta08 [September 10, 2011]
+ Fixed 64-bit compilation errors (gcc). The errors fixed relate
+ to conditions where types that are 32 bits in the GCC 32-bit
+ world (uLong and png_size_t) become 64 bits in the 64-bit
+ world. This produces potential truncation errors which the
+ compiler correctly flags.
+ Relocated new HAVE_SOLARIS_LD definition in configure.ac
+ Constant changes for 64-bit compatibility (removal of L suffixes). The
+ 16-bit cases still use "L" as we don't have a 16-bit test system.
+
+Version 1.5.5rc01 [September 15, 2011]
+ Removed "L" suffixes in pngpriv.h
+
+Version 1.5.5 [September 22, 2011]
+ No changes.
+
+Version 1.5.6beta01 [September 22, 2011]
+ Fixed some 64-bit type conversion warnings in pngrtran.c
+ Moved row_info from png_struct to a local variable.
+ The various interlace mask arrays have been made into arrays of
+ bytes and made PNG_CONST and static (previously some arrays were
+ marked PNG_CONST and some weren't).
+ Additional checks have been added to the transform code to validate the
+ pixel depths after the transforms on both read and write.
+ Removed some redundant code from pngwrite.c, in png_destroy_write_struct().
+ Changed chunk reading/writing code to use png_uint_32 instead of png_byte[4].
+ This removes the need to allocate temporary strings for chunk names on
+ the stack in the read/write code. Unknown chunk handling still uses the
+ string form because this is exposed in the API.
+
+Version 1.5.6beta02 [September 26, 2011]
+ Added a note in the manual the png_read_update_info() must be called only
+ once with a particular info_ptr.
+ Fixed a typo in the definition of the new PNG_STRING_FROM_CHUNK(s,c) macro.
+
+Version 1.5.6beta03 [September 28, 2011]
+ Revised test-pngtest.sh to report FAIL when pngtest fails.
+ Added "--strict" option to pngtest, to report FAIL when the failure is
+ only because the resulting valid files are different.
+ Revised CMakeLists.txt to work with mingw and removed some material from
+ CMakeLists.txt that is no longer useful in libpng-1.5.
+
+Version 1.5.6beta04 [October 5, 2011]
+ Fixed typo in Makefile.in and Makefile.am ("-M Wl" should be "-M -Wl")."
+
+Version 1.5.6beta05 [October 12, 2011]
+ Speed up png_combine_row() for interlaced images. This reduces the generality
+ of the code, allowing it to be optimized for Adam7 interlace. The masks
+ passed to png_combine_row() are now generated internally, avoiding
+ some code duplication and localizing the interlace handling somewhat.
+ Align png_struct::row_buf - previously it was always unaligned, caused by
+ a bug in the code that attempted to align it; the code needs to subtract
+ one from the pointer to take account of the filter byte prepended to
+ each row.
+ Optimized png_combine_row() when rows are aligned. This gains a small
+ percentage for 16-bit and 32-bit pixels in the typical case where the
+ output row buffers are appropriately aligned. The optimization was not
+ previously possible because the png_struct buffer was always misaligned.
+ Fixed bug in png_write_chunk_header() debug print, introduced in 1.5.6beta01.
+
+Version 1.5.6beta06 [October 17, 2011]
+ Removed two redundant tests for uninitialized row.
+ Fixed a relatively harmless memory overwrite in compressed text writing
+ with a 1 byte zlib buffer.
+ Add ability to call png_read_update_info multiple times to pngvalid.c.
+ Fixes for multiple calls to png_read_update_info. These fixes attend to
+ most of the errors revealed in pngvalid, however doing the gamma work
+ twice results in inaccuracies that can't be easily fixed. There is now
+ a warning in the code if this is going to happen.
+ Turned on multiple png_read_update_info in pngvalid transform tests.
+ Prevent libpng from overwriting unused bits at the end of the image when
+ it is not byte aligned, while reading. Prior to libpng-1.5.6 libpng would
+ overwrite the partial byte at the end of each row if the row width was not
+ an exact multiple of 8 bits and the image is not interlaced.
+
+Version 1.5.6beta07 [October 21, 2011]
+ Made png_ptr->prev_row an aligned pointer into png_ptr->big_prev_row
+ (Mans Rullgard).
+
+Version 1.5.6rc01 [October 26, 2011]
+ Changed misleading "Missing PLTE before cHRM" warning to "Out of place cHRM"
+
+Version 1.5.6rc02 [October 27, 2011]
+ Added LSR() macro to defend against buggy compilers that evaluate non-taken
+ code branches and complain about out-of-range shifts.
+
+Version 1.5.6rc03 [October 28, 2011]
+ Renamed the LSR() macro to PNG_LSR() and added PNG_LSL() macro.
+ Fixed compiler warnings with Intel and MSYS compilers. The logical shift
+ fix for Microsoft Visual C is required by other compilers, so this
+ enables that fix for all compilers when using compile-time constants.
+ Under MSYS 'byte' is a name declared in a system header file, so we
+ changed the name of a local variable to avoid the warnings that result.
+ Added #define PNG_ALIGN_TYPE PNG_ALIGN_NONE to contrib/pngminim/*/pngusr.h
+
+Version 1.5.6 [November 3, 2011]
+ No changes.
+
+Version 1.5.7beta01 [November 4, 2011]
+ Added support for ARM processor, when decoding all PNG up-filtered rows
+ and any other-filtered rows with 3 or 4 bytes per pixel (Mans Rullgard).
+ Fixed bug in pngvalid on early allocation failure; fixed type cast in
+ pngmem.c; pngvalid would attempt to call png_error() if the allocation
+ of a png_struct or png_info failed. This would probably have led to a
+ crash. The pngmem.c implementation of png_malloc() included a cast
+ to png_size_t which would fail on large allocations on 16-bit systems.
+ Fix for the preprocessor of the Intel C compiler. The preprocessor
+ splits adjacent @ signs with a space; this changes the concatenation
+ token from @-@-@ to PNG_JOIN; that should work with all compiler
+ preprocessors.
+ Paeth filter speed improvements from work by Siarhei Siamashka. This
+ changes the 'Paeth' reconstruction function to improve the GCC code
+ generation on x86. The changes are only part of the suggested ones;
+ just the changes that definitely improve speed and remain simple.
+ The changes also slightly increase the clarity of the code.
+
+Version 1.5.7beta02 [November 11, 2011]
+ Check compression_type parameter in png_get_iCCP and remove spurious
+ casts. The compression_type parameter is always assigned to, so must
+ be non-NULL. The cast of the profile length potentially truncated the
+ value unnecessarily on a 16-bit int system, so the cast of the (byte)
+ compression type to (int) is specified by ANSI-C anyway.
+ Fixed FP division by zero in pngvalid.c; the 'test_pixel' code left
+ the sBIT fields in the test pixel as 0, which resulted in a floating
+ point division by zero which was irrelevant but causes systems where
+ FP exceptions cause a crash. Added code to pngvalid to turn on FP
+ exceptions if the appropriate glibc support is there to ensure this is
+ tested in the future.
+ Updated scripts/pnglibconf.mak and scripts/makefile.std to handle the
+ new PNG_JOIN macro.
+ Added versioning to pnglibconf.h comments.
+ Simplified read/write API initial version; basic read/write tested on
+ a variety of images, limited documentation (in the header file.)
+ Installed more accurate linear to sRGB conversion tables. The slightly
+ modified tables reduce the number of 16-bit values that
+ convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used
+ to generate the tables is now in a contrib/sRGBtables sub-directory.
+
+Version 1.5.7beta03 [November 17, 2011]
+ Removed PNG_CONST from the sRGB table declarations in pngpriv.h and png.c
+ Added run-time detection of NEON support.
+ Added contrib/libtests; includes simplified API test and timing test and
+ a color conversion utility for rapid checking of failed 'pngstest' results.
+ Multiple transform bug fixes plus a work-round for double gamma correction.
+ libpng does not support more than one transform that requires linear data
+ at once - if this is tried typically the results is double gamma
+ correction. Since the simplified APIs can need rgb to gray combined with
+ a compose operation it is necessary to do one of these outside the main
+ libpng transform code. This check-in also contains fixes to various bugs
+ in the simplified APIs themselves and to some bugs in compose and rgb to
+ gray (on palette) itself.
+ Fixes for C++ compilation using g++ When libpng source is compiled
+ using g++. The compiler imposes C++ rules on the C source; thus it
+ is desirable to make the source work with either C or C++ rules
+ without throwing away useful error information. This change adds
+ png_voidcast to allow C semantic (void*) cases or the corresponding
+ C++ static_cast operation, as appropriate.
+ Added --noexecstack to assembler file compilation. GCC does not set
+ this on assembler compilation, even though it does on C compilation.
+ This creates security issues if assembler code is enabled; the
+ work-around is to set it by default in the flags for $(CCAS)
+ Work around compilers that don't support declaration of const data. Some
+ compilers fault 'extern const' data declarations (because the data is
+ not initialized); this turns on const-ness only for compilers where
+ this is known to work.
+
+Version 1.5.7beta04 [November 17, 2011]
+ Since the gcc driver does not recognize the --noexecstack flag, we must
+ use the -Wa prefix to have it passed through to the assembler.
+ Also removed a duplicate setting of this flag.
+ Added files that were omitted from the libpng-1.5.7beta03 zip distribution.
+
+Version 1.5.7beta05 [November 25, 2011]
+ Removed "zTXt" from warning in generic chunk decompression function.
+ Validate time settings passed to png_set_tIME() and png_convert_to_rfc1123()
+ (Frank Busse). Note: This prevented CVE-2015-7981 from affecting
+ libpng-1.5.7 and later.
+ Added MINGW support to CMakeLists.txt
+ Reject invalid compression flag or method when reading the iTXt chunk.
+ Backed out 'simplified' API changes. The API seems too complex and there
+ is a lack of consensus or enthusiasm for the proposals. The API also
+ reveals significant bugs inside libpng (double gamma correction and the
+ known bug of being unable to retrieve a corrected palette). It seems
+ better to wait until the bugs, at least, are corrected.
+ Moved pngvalid.c into contrib/libtests
+ Rebuilt Makefile.in, configure, etc., with autoconf-2.68
+
+Version 1.5.7rc01 [December 1, 2011]
+ Replaced an "#if" with "#ifdef" in pngrtran.c
+ Revised #if PNG_DO_BC block in png.c (use #ifdef and add #else)
+
+Version 1.5.7rc02 [December 5, 2011]
+ Revised project files and contrib/pngvalid/pngvalid.c to account for
+ the relocation of pngvalid into contrib/libtests.
+ Revised pngconf.h to use " __declspec(restrict)" only when MSC_VER >= 1400,
+ as in libpng-1.5.4.
+ Put CRLF line endings in the owatcom project files.
+
+Version 1.5.7rc03 [December 7, 2011]
+ Updated CMakeLists.txt to account for the relocation of pngvalid.c
+
+Version 1.5.7 [December 15, 2011]
+ Minor fixes to pngvalid.c for gcc 4.6.2 compatibility to remove warnings
+ reported by earlier versions.
+ Fixed minor memset/sizeof errors in pngvalid.c.
+
+Version 1.6.0beta01 [December 15, 2011]
+ Removed machine-generated configure files from the GIT repository (they will
+ continue to appear in the tarball distributions and in the libpng15 and
+ earlier GIT branches).
+ Restored the new 'simplified' API, which was started in libpng-1.5.7beta02
+ but later deleted from libpng-1.5.7beta05.
+ Added example programs for the new 'simplified' API.
+ Added ANSI-C (C90) headers and require them, and take advantage of the
+ change. Also fixed some of the projects/* and contrib/* files that needed
+ updates for libpng16 and the move of pngvalid.c.
+ With this change the required ANSI-C header files are assumed to exist: the
+ implementation must provide float.h, limits.h, stdarg.h and stddef.h and
+ libpng relies on limits.h and stddef.h existing and behaving as defined
+ (the other two required headers aren't used). Non-ANSI systems that don't
+ have stddef.h or limits.h will have to provide an appropriate fake
+ containing the relevant types and #defines.
+ Dropped support for 16-bit platforms. The use of FAR/far has been eliminated
+ and the definition of png_alloc_size_t is now controlled by a flag so
+ that 'small size_t' systems can select it if necessary. Libpng 1.6 may
+ not currently work on such systems -- it seems likely that it will
+ ask 'malloc' for more than 65535 bytes with any image that has a
+ sufficiently large row size (rather than simply failing to read such
+ images).
+ New tools directory containing tools used to generate libpng code.
+ Fixed race conditions in parallel make builds. With higher degrees of
+ parallelism during 'make' the use of the same temporary file names such
+ as 'dfn*' can result in a race where a temporary file from one arm of the
+ build is deleted or overwritten in another arm. This changes the
+ temporary files for suffix rules to always use $* and ensures that the
+ non-suffix rules use unique file names.
+
+Version 1.6.0beta02 [December 21, 2011]
+ Correct configure builds where build and source directories are separate.
+ The include path of 'config.h' was erroneously made relative in pngvalid.c
+ in libpng 1.5.7.
+
+Version 1.6.0beta03 [December 22, 2011]
+ Start-up code size improvements, error handler flexibility. These changes
+ alter how the tricky allocation of the initial png_struct and png_info
+ structures are handled. png_info is now handled in pretty much the same
+ way as everything else, except that the allocations handle NULL return
+ silently. png_struct is changed in a similar way on allocation and on
+ deallocation a 'safety' error handler is put in place (which should never
+ be required). The error handler itself is changed to permit mismatches
+ in the application and libpng error buffer size; however, this means a
+ silent change to the API to return the jmp_buf if the size doesn't match
+ the size from the libpng compilation; libpng now allocates the memory and
+ this may fail. Overall these changes result in slight code size
+ reductions; however, this is a reduction in code that is always executed
+ so is particularly valuable. Overall on a 64-bit system the libpng DLL
+ decreases in code size by 1733 bytes. pngerror.o increases in size by
+ about 465 bytes because of the new functionality.
+ Added png_convert_to_rfc1123_buffer() and deprecated png_convert_to_rfc1123()
+ to avoid including a spurious buffer in the png_struct.
+
+Version 1.6.0beta04 [December 30, 2011]
+ Regenerated configure scripts with automake-1.11.2
+ Eliminated png_info_destroy(). It is now used only in png.c and only calls
+ one other internal function and memset().
+ Enabled png_get_sCAL_fixed() if floating point APIs are enabled. Previously
+ it was disabled whenever internal fixed point arithmetic was selected,
+ which meant it didn't exist even on systems where FP was available but not
+ preferred.
+ Added pngvalid.c compile time checks for const APIs.
+ Implemented 'restrict' for png_info and png_struct. Because of the way
+ libpng works both png_info and png_struct are always accessed via a
+ single pointer. This means adding C99 'restrict' to the pointer gives
+ the compiler some opportunity to optimize the code. This change allows
+ that.
+ Moved AC_MSG_CHECKING([if libraries can be versioned]) later to the proper
+ location in configure.ac (Gilles Espinasse).
+ Changed png_memcpy to C assignment where appropriate. Changed all those
+ uses of png_memcpy that were doing a simple assignment to assignments
+ (all those cases where the thing being copied is a non-array C L-value).
+ Added some error checking to png_set_*() routines.
+ Removed the reference to the non-exported function png_memcpy() from
+ example.c.
+ Fixed the Visual C 64-bit build - it requires jmp_buf to be aligned, but
+ it had become misaligned.
+ Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32
+ and unsigned long are of different sizes.
+
+Version 1.6.0beta05 [January 15, 2012]
+ Updated manual with description of the simplified API (copied from png.h)
+ Fix bug in pngerror.c: some long warnings were being improperly truncated
+ (CVE-2011-3464, bug introduced in libpng-1.5.3beta05).
+
+Version 1.6.0beta06 [January 24, 2012]
+ Added palette support to the simplified APIs. This commit
+ changes some of the macro definitions in png.h, app code
+ may need corresponding changes.
+ Increased the formatted warning buffer to 192 bytes.
+ Added color-map support to simplified API. This is an initial version for
+ review; the documentation has not yet been updated.
+ Fixed Min/GW uninstall to remove libpng.dll.a
+
+Version 1.6.0beta07 [January 28, 2012]
+ Eliminated Intel icc/icl compiler warnings. The Intel (GCC derived)
+ compiler issues slightly different warnings from those issued by the
+ current vesions of GCC. This eliminates those warnings by
+ adding/removing casts and small code rewrites.
+ Updated configure.ac from autoupdate: added --enable-werror option.
+ Also some layout regularization and removal of introduced tab characters
+ (replaced with 3-character indentation). Obsolete macros identified by
+ autoupdate have been removed; the replacements are all in 2.59 so
+ the pre-req hasn't been changed. --enable-werror checks for support
+ for -Werror (or the given argument) in the compiler. This mimics the
+ gcc configure option by allowing -Werror to be turned on safely; without
+ the option the tests written in configure itself fail compilation because
+ they cause compiler warnings.
+ Rewrote autogen.sh to run autoreconf instead of running tools one-by-one.
+ Conditionalize the install rules for MINGW and CYGWIN in CMakeLists.txt and
+ set CMAKE_LIBRARY_OUTPUT_DIRECTORY to "lib" on all platforms (C. Yapp).
+ Freeze libtool files in the 'scripts' directory. This version of autogen.sh
+ attempts to dissuade people from running it when it is not, or should not,
+ be necessary. In fact, autogen.sh does not work when run in a libpng
+ directory extracted from a tar distribution anymore. You must run it in
+ a GIT clone instead.
+ Added two images to contrib/pngsuite (1-bit and 2-bit transparent grayscale),
+ and renamed three whose names were inconsistent with those in
+ pngsuite/README.txt.
+
+Version 1.6.0beta08 [February 1, 2012]
+ Fixed Image::colormap misalignment in pngstest.c
+ Check libtool/libtoolize version number (2.4.2) in configure.ac
+ Divide test-pngstest.sh into separate pngstest runs for basic and
+ transparent images.
+ Moved automake options to AM_INIT_AUTOMAKE in configure.ac
+ Added color-tests, silent-rules (Not yet implemented in Makefile.am) and
+ version checking to configure.ac
+ Improved pngstest speed by not doing redundant tests and add const to
+ the background parameter of png_image_finish_read. The --background
+ option is now done automagically only when required, so that commandline
+ option no longer exists.
+ Cleaned up pngpriv.h to consistently declare all functions and data.
+ Also eliminated PNG_CONST_DATA, which is apparently not needed but we
+ can't be sure until it is gone.
+ Added symbol prefixing that allows all the libpng external symbols
+ to be prefixed (suggested by Reuben Hawkins).
+ Updated "ftbb*.png" list in the owatcom and vstudio projects.
+ Fixed 'prefix' builds on clean systems. The generation of pngprefix.h
+ should not require itself.
+ Updated INSTALL to explain that autogen.sh must be run in a GIT clone,
+ not in a libpng directory extracted from a tar distribution.
+
+Version 1.6.0beta09 [February 1, 2012]
+ Reverted the prebuilt configure files to libpng-1.6.0beta05 condition.
+
+Version 1.6.0beta10 [February 3, 2012]
+ Added Z_SOLO for zlib-1.2.6+ and correct pngstest tests
+ Updated list of test images in CMakeLists.txt
+ Updated the prebuilt configure files to current condition.
+ Revised INSTALL information about autogen.sh; it works in tar distributions.
+
+Version 1.6.0beta11 [February 16, 2012]
+ Fix character count in pngstest command in projects/owatcom/pngstest.tgt
+ Revised test-pngstest.sh to report PASS/FAIL for each image.
+ Updated documentation about the simplified API.
+ Corrected estimate of error in libpng png_set_rgb_to_gray API. The API is
+ extremely inaccurate for sRGB conversions because it uses an 8-bit
+ intermediate linear value and it does not use the sRGB transform, so it
+ suffers from the known instability in gamma transforms for values close
+ to 0 (see Poynton). The net result is that the calculation has a maximum
+ error of 14.99/255; 0.5/255^(1/2.2). pngstest now uses 15 for the
+ permitted 8-bit error. This may still not be enough because of arithmetic
+ error.
+ Removed some unused arrays (with #ifdef) from png_read_push_finish_row().
+ Fixed a memory overwrite bug in simplified read of RGB PNG with
+ non-linear gamma Also bugs in the error checking in pngread.c and changed
+ quite a lot of the checks in pngstest.c to be correct; either correctly
+ written or not over-optimistic. The pngstest changes are insufficient to
+ allow all possible RGB transforms to be passed; pngstest cmppixel needs
+ to be rewritten to make it clearer which errors it allows and then changed
+ to permit known inaccuracies.
+ Removed tests for no-longer-used *_EMPTY_PLTE_SUPPORTED from pngstruct.h
+ Fixed fixed/float API export conditionals. 1) If FIXED_POINT or
+ FLOATING_POINT options were switched off, png.h ended up with lone ';'
+ characters. This is not valid ANSI-C outside a function. The ';'
+ characters have been moved inside the definition of PNG_FP_EXPORT and
+ PNG_FIXED_EXPORT. 2) If either option was switched off, the declaration
+ of the corresponding functions were completely omitted, even though some
+ of them are still used internally. The result is still valid, but
+ produces warnings from gcc with some warning options (including -Wall). The
+ fix is to cause png.h to declare the functions with PNG_INTERNAL_FUNCTION
+ when png.h is included from pngpriv.h.
+ Check for invalid palette index while reading paletted PNG. When one is
+ found, issue a warning and increase png_ptr->num_palette accordingly.
+ Apps are responsible for checking to see if that happened.
+
+Version 1.6.0beta12 [February 18, 2012]
+ Do not increase num_palette on invalid_index.
+ Relocated check for invalid palette index to pngrtran.c, after unpacking
+ the sub-8-bit pixels.
+ Fixed CVE-2011-3026 buffer overrun bug. This bug was introduced when
+ iCCP chunk support was added at libpng-1.0.6. Deal more correctly with the
+ test on iCCP chunk length. Also removed spurious casts that may hide
+ problems on 16-bit systems.
+
+Version 1.6.0beta13 [February 24, 2012]
+ Eliminated redundant png_push_read_tEXt|zTXt|iTXt|unknown code from
+ pngpread.c and use the sequential png_handle_tEXt, etc., in pngrutil.c;
+ now that png_ptr->buffer is inaccessible to applications, the special
+ handling is no longer useful.
+ Added PNG_SAFE_LIMITS feature to pnglibconf.dfa, pngpriv.h, and new
+ pngusr.dfa to reset the user limits to safe ones if PNG_SAFE_LIMITS is
+ defined. To enable, use "CPPFLAGS=-DPNG_SAFE_LIMITS_SUPPORTED=1" on the
+ configure command or put #define PNG_SAFE_LIMITS_SUPPORTED in
+ pnglibconf.h.prebuilt and pnglibconf.h.
+
+Version 1.6.0beta14 [February 27, 2012]
+ Added information about the new limits in the manual.
+ Updated Makefile.in
+
+Version 1.6.0beta15 [March 2, 2012]
+ Removed unused "current_text" members of png_struct and the png_free()
+ of png_ptr->current_text from pngread.c
+ Rewrote pngstest.c for substantial speed improvement.
+ Fixed transparent pixel and 16-bit rgb tests in pngstest and removed a
+ spurious check in pngwrite.c
+ Added PNG_IMAGE_FLAG_FAST for the benefit of applications that store
+ intermediate files, or intermediate in-memory data, while processing
+ image data with the simplified API. The option makes the files larger
+ but faster to write and read. pngstest now uses this by default; this
+ can be disabled with the --slow option.
+ Improved pngstest fine tuning of error numbers, new test file generator.
+ The generator generates images that test the full range of sample values,
+ allow the error numbers in pngstest to be tuned and checked. makepng
+ also allows generation of images with extra chunks, although this is
+ still work-in-progress.
+ Added check for invalid palette index while reading.
+ Fixed some bugs in ICC profile writing. The code should now accept
+ all potentially valid ICC profiles and reject obviously invalid ones.
+ It now uses png_error() to do so rather than casually writing a PNG
+ without the necessary color data.
+ Removed whitespace from the end of lines in all source files and scripts.
+
+Version 1.6.0beta16 [March 6, 2012]
+ Relocated palette-index checking function from pngrutil.c to pngtrans.c
+ Added palette-index checking while writing.
+ Changed png_inflate() and calling routines to avoid overflow problems.
+ This is an intermediate check-in that solves the immediate problems and
+ introduces one performance improvement (avoiding a copy via png_ptr->zbuf.)
+ Further changes will be made to make ICC profile handling more secure.
+ Fixed build warnings (MSVC, GCC, GCC v3). Cygwin GCC with default options
+ declares 'index' as a global, causing a warning if it is used as a local
+ variable. GCC 64-bit warns about assigning a (size_t) (unsigned 64-bit)
+ to an (int) (signed 32-bit). MSVC, however, warns about using the
+ unary '-' operator on an unsigned value (even though it is well defined
+ by ANSI-C to be ~x+1). The padding calculation was changed to use a
+ different method. Removed the tests on png_ptr->pass.
+ Added contrib/libtests/tarith.c to test internal arithmetic functions from
+ png.c. This is a libpng maintainer program used to validate changes to the
+ internal arithmetic functions.
+ Made read 'inflate' handling like write 'deflate' handling. The read
+ code now claims and releases png_ptr->zstream, like the write code.
+ The bug whereby the progressive reader failed to release the zstream
+ is now fixed, all initialization is delayed, and the code checks for
+ changed parameters on deflate rather than always calling
+ deflatedEnd/deflateInit.
+ Validate the zTXt strings in pngvalid.
+ Added code to validate the windowBits value passed to deflateInit2().
+ If the call to deflateInit2() is wrong a png_warning will be issued
+ (in fact this is harmless, but the PNG data produced may be sub-optimal).
+
+Version 1.6.0beta17 [March 10, 2012]
+ Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
+ Reject all iCCP chunks after the first, even if the first one is invalid.
+ Deflate/inflate was reworked to move common zlib calls into single
+ functions [rw]util.c. A new shared keyword check routine was also added
+ and the 'zbuf' is no longer allocated on progressive read. It is now
+ possible to call png_inflate() incrementally. A warning is no longer
+ issued if the language tag or translated keyword in the iTXt chunk
+ has zero length.
+ If benign errors are disabled use maximum window on ancillary inflate.
+ This works round a bug introduced in 1.5.4 where compressed ancillary
+ chunks could end up with a too-small windowBits value in the deflate
+ header.
+
+Version 1.6.0beta18 [March 16, 2012]
+ Issue a png_benign_error() instead of png_warning() about bad palette index.
+ In pngtest, treat benign errors as errors if "-strict" is present.
+ Fixed an off-by-one error in the palette index checking function.
+ Fixed a compiler warning under Cygwin (Windows-7, 32-bit system)
+ Revised example.c to put text strings in a temporary character array
+ instead of directly assigning string constants to png_textp members.
+ This avoids compiler warnings when -Wwrite-strings is enabled.
+ Added output flushing to aid debugging under Visual Studio. Unfortunately
+ this is necessary because the VS2010 output window otherwise simply loses
+ the error messages on error (they weren't flushed to the window before
+ the process exited, apparently!)
+ Added configuration support for benign errors and changed the read
+ default. Also changed some warnings in the iCCP and sRGB handling
+ from to benign errors. Configuration now makes read benign
+ errors warnings and write benign errors to errors by default (thus
+ changing the behavior on read). The simplified API always forces
+ read benign errors to warnings (regardless of the system default, unless
+ this is disabled in which case the simplified API can't be built.)
+
+Version 1.6.0beta19 [March 18, 2012]
+ Work around for duplicate row start calls; added warning messages.
+ This turns on PNG_FLAG_DETECT_UNINITIALIZED to detect app code that
+ fails to call one of the 'start' routines (not enabled in libpng-1.5
+ because it is technically an API change, since it did normally work
+ before.) It also makes duplicate calls to png_read_start_row (an
+ internal function called at the start of the image read) benign, as
+ they were before changes to use png_inflate_claim. Somehow webkit is
+ causing this to happen; this is probably a mis-feature in the zlib
+ changes so this commit is only a work-round.
+ Removed erroneous setting of DETECT_UNINITIALIZED and added more
+ checks. The code now does a png_error if an attempt is made to do the
+ row initialization twice; this is an application error and it has
+ serious consequences because the transform data in png_struct is
+ changed by each call.
+ Added application error reporting and added chunk names to read
+ benign errors; also added --strict to pngstest - not enabled
+ yet because a warning is produced.
+ Avoid the double gamma correction warning in the simplified API.
+ This allows the --strict option to pass in the pngstest checks
+
+Version 1.6.0beta20 [March 29, 2012]
+ Changed chunk handler warnings into benign errors, incrementally load iCCP
+ Added checksum-icc.c to contrib/tools
+ Prevent PNG_EXPAND+PNG_SHIFT doing the shift twice.
+ Recognize known sRGB ICC profiles while reading; prefer writing the
+ iCCP profile over writing the sRGB chunk, controlled by the
+ PNG_sRGB_PROFILE_CHECKS option.
+ Revised png_set_text_2() to avoid potential memory corruption (fixes
+ CVE-2011-3048, also known as CVE-2012-3425).
+
+Version 1.6.0beta21 [April 27, 2012]
+ Revised scripts/makefile.darwin: use system zlib; remove quotes around
+ architecture list; add missing ppc architecture; add architecture options
+ to shared library link; don't try to create a shared lib based on missing
+ RELEASE variable.
+ Enable png_set_check_for_invalid_index() for both read and write.
+ Removed #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED in pngpriv.h around
+ declaration of png_handle_unknown().
+ Added -lssp_nonshared in a comment in scripts/makefile.freebsd
+ and changed deprecated NOOBJ and NOPROFILE to NO_OBJ and NO_PROFILE.
+
+Version 1.6.0beta22 [May 23, 2012]
+ Removed need for -Wno-cast-align with clang. clang correctly warns on
+ alignment increasing pointer casts when -Wcast-align is passed. This
+ fixes the cases that clang warns about either by eliminating the
+ casts from png_bytep to png_uint_16p (pngread.c), or, for pngrutil.c
+ where the cast is previously verified or pngstest.c where it is OK, by
+ introducing new png_aligncast macros to do the cast in a way that clang
+ accepts.
+
+Version 1.6.0beta23 [June 6, 2012]
+ Revised CMakeLists.txt to not attempt to make a symlink under mingw.
+ Made fixes for new optimization warnings from gcc 4.7.0. The compiler
+ performs an optimization which is safe; however it then warns about it.
+ Changing the type of 'palette_number' in pngvalid.c removes the warning.
+ Do not depend upon a GCC feature macro being available for use in generating
+ the linker mapfile symbol prefix.
+ Improved performance of new do_check_palette_indexes() function (only
+ update the value when it actually increases, move test for whether
+ the check is wanted out of the function.
+
+Version 1.6.0beta24 [June 7, 2012]
+ Don't check palette indexes if num_palette is 0 (as it can be in MNG files).
+
+Version 1.6.0beta25 [June 16, 2012]
+ Revised png_set_keep_unknown_chunks() so num_chunks < 0 means ignore all
+ unknown chunks and all known chunks except for IHDR, PLTE, tRNS, IDAT,
+ and IEND. Previously it only meant ignore all unknown chunks, the
+ same as num_chunks == 0. Revised png_image_skip_unused_chunks() to
+ provide a list of chunks to be processed instead of a list of chunks to
+ ignore. Revised contrib/gregbook/readpng2.c accordingly.
+
+Version 1.6.0beta26 [July 10, 2012]
+ Removed scripts/makefile.cegcc from the *.zip and *.7z distributions; it
+ depends on configure, which is not included in those archives.
+ Moved scripts/chkfmt to contrib/tools.
+ Changed "a+w" to "u+w" in Makefile.in to fix CVE-2012-3386.
+
+Version 1.6.0beta27 [August 11, 2012]
+ Do not compile PNG_DEPRECATED, PNG_ALLOC and PNG_PRIVATE when __GNUC__ < 3.
+ Do not use __restrict when GNUC is <= 3.1
+ Removed references to png_zalloc() and png_zfree() from the manual.
+ Fixed configurations where floating point is completely disabled. Because
+ of the changes to support symbol prefixing PNG_INTERNAL_FUNCTION declares
+ floating point APIs during libpng builds even if they are completely
+ disabled. This requires the png floating point types (png_double*) to be
+ declared even though the functions are never actually defined. This
+ change provides a dummy definition so that the declarations work, yet any
+ implementation will fail to compile because of an incomplete type.
+ Re-eliminated the use of strcpy() in pngtest.c. An unnecessary use of
+ strcpy() was accidentally re-introduced in libpng16; this change replaces
+ it with strncpy().
+ Eliminated use of png_sizeof(); use sizeof() instead.
+ Use a consistent style for (sizeof type) and (sizeof (array))
+ Cleanup of png_set_filler(). This function does very different things on
+ read and write. In libpng 1.6 the two cases can be distinguished and
+ considerable code cleanup, and extra error checking, is possible. This
+ makes calls on the write side that have no effect be ignored with a
+ png_app_error(), which can be disabled in the app using
+ png_set_benign_errors(), and removes the spurious use of usr_channels
+ on the read side.
+ Insist on autotools 1.12.1 for git builds because there are security issues
+ with 1.12 and insisting on anything less would allow 1.12 to be used.
+ Removed info_ptr->signature[8] from WRITE-only builds.
+ Add some conditions for compiling png_fixed(). This is a small function
+ but it requires "-lm" on some platforms.
+ Cause pngtest --strict to fail on any warning from libpng (not just errors)
+ and cause it not to fail at the comparison step if libpng lacks support
+ for writing chunks that it reads from the input (currently only implemented
+ for compressed text chunks).
+ Make all three "make check" test programs work without READ or WRITE support.
+ Now "make check" will succeed even if libpng is compiled with -DPNG_NO_READ
+ or -DPNG_NO_WRITE. The tests performed are reduced, but the basic reading
+ and writing of a PNG file is always tested by one or more of the tests.
+ Consistently use strlen(), memset(), memcpy(), and memcmp() instead of the
+ png_strlen(), png_memset(), png_memcpy(), and png_memcmp() macros.
+ Removed the png_sizeof(), png_strlen(), png_memset(), png_memcpy(), and
+ png_memcmp() macros.
+ Work around gcc 3.x and Microsoft Visual Studio 2010 complaints. Both object
+ to the split initialization of num_chunks.
+
+Version 1.6.0beta28 [August 29, 2012]
+ Unknown handling fixes and clean up. This adds more correct option
+ control of the unknown handling, corrects the pre-existing bug where
+ the per-chunk 'keep' setting is ignored and makes it possible to skip
+ IDAT chunks in the sequential reader (broken in earlier 1.6 versions).
+ There is a new test program, test-unknown.c, which is a work in progress
+ (not currently part of the test suite). Comments in the header files now
+ explain how the unknown handling works.
+ Allow fine grain control of unknown chunk APIs. This change allows
+ png_set_keep_unknown_chunks() to be turned off if not required and causes
+ both read and write to behave appropriately (on read this is only possible
+ if the user callback is used to handle unknown chunks). The change
+ also removes the support for storing unknown chunks in the info_struct
+ if the only unknown handling enabled is via the callback, allowing libpng
+ to be configured with callback reading and none of the unnecessary code.
+ Corrected fix for unknown handling in pngtest. This reinstates the
+ libpng handling of unknown chunks other than vpAg and sTER (including
+ unsafe-to-copy chunks which were dropped before) and eliminates the
+ repositioning of vpAg and sTER in pngtest.png by changing pngtest.png
+ (so the chunks are where libpng would put them).
+ Added "tunknown" test and corrected a logic error in png_handle_unknown()
+ when SAVE support is absent. Moved the shell test scripts for
+ contrib/libtests from the libpng top directory to contrib/libtests.
+ png_handle_unknown() must always read or skip the chunk, if
+ SAVE_UNKNOWN_CHUNKS is turned off *and* the application does not set
+ a user callback an unknown chunk will not be read, leading to a read
+ error, which was revealed by the "tunknown" test.
+ Cleaned up and corrected ICC profile handling.
+ contrib/libtests/makepng: corrected 'rgb' and 'gray' cases. profile_error
+ messages could be truncated; made a correct buffer size calculation and
+ adjusted pngerror.c appropriately. png_icc_check_* checking improved;
+ changed the functions to receive the correct color type of the PNG on read
+ or write and check that it matches the color space of the profile (despite
+ what the comments said before, there is danger in assuming the app will
+ cope correctly with an RGB profile on a grayscale image and, since it
+ violates the PNG spec, allowing it is certain to produce inconsistent
+ app behavior and might even cause app crashes.) Check that profiles
+ contain the tags needed to process the PNG (tags all required by the ICC
+ spec). Removed unused PNG_STATIC from pngpriv.h.
+
+Version 1.6.0beta29 [September 4, 2012]
+ Fixed the simplified API example programs to add the *colormap parameter
+ to several of he API and improved the error message if the version field
+ is not set.
+ Added contrib/examples/* to the *.zip and *.7z distributions.
+ Updated simplified API synopses and description of the png_image structure
+ in the manual.
+ Made makepng and pngtest produce identical PNGs, add "--relaxed" option
+ to pngtest. The "--relaxed" option turns off the benign errors that are
+ enabled by default in pre-RC builds. makepng can now write ICC profiles
+ where the length has not been extended to a multiple of 4, and pngtest
+ now intercepts all libpng errors, allowing the previously-introduced
+ "--strict test" on no warnings to actually work.
+ Improved ICC profile handling including cHRM chunk generation and fixed
+ Cygwin+MSVC build errors. The ICC profile handling now includes more
+ checking. Several errors that caused rejection of the profile are now
+ handled with a warning in such a way that the invalid profiles will be
+ read by default in release (but not pre-RC) builds but will not be
+ written by default. The easy part of handling the cHRM chunk is written,
+ where the ICC profile contains the required data. The more difficult
+ part plus guessing a gAMA value requires code to pass selected RGB values
+ through the profile.
+
+Version 1.6.0beta30 [October 24, 2012]
+ Changed ICC profile matrix/vector types to not depend on array type rules.
+ By the ANSI-C standard the new types should be identical to the previous
+ versions, and all known versions of gcc tested with the previous versions
+ except for GCC-4.2.1 work with this version. The change makes the ANSI-C
+ rule that const applied to an array of elements applies instead to the
+ elements in the array moot by explicitly applying const to the base
+ elements of the png_icc_matrix and png_icc_vector types. The accidental
+ (harmless) 'const' previously applied to the parameters of two of the
+ functions have also been removed.
+ Added a work around for GCC 4.2 optimization bug.
+ Marked the broken (bad white point) original HP sRGB profiles correctly and
+ correct comments.
+ Added -DZ_SOLO to contrib/pngminim/*/makefile to work with zlib-1.2.7
+ Use /MDd for vstudio debug builds. Also added pngunkown to the vstudio
+ builds, fixed build errors and corrected a minor exit code error in
+ pngvalid if the 'touch' file name is invalid.
+ Add updated WARNING file to projects/vstudio from libpng 1.5/vstudio
+ Fixed build when using #define PNG_NO_READ_GAMMA in png_do_compose() in
+ pngrtran.c (Domani Hannes).
+
+Version 1.6.0beta31 [November 1, 2012]
+ Undid the erroneous change to vstudio/pngvalid build in libpng-1.6.0beta30.
+ Made pngvalid so that it will build outside the libpng source tree.
+ Made builds -DPNG_NO_READ_GAMMA compile (the unit tests still fail).
+ Made PNG_NO_READ_GAMMA switch off interfaces that depend on READ_GAMMA.
+ Prior to 1.6.0 switching off READ_GAMMA did unpredictable things to the
+ interfaces that use it (specifically, png_do_background in 1.4 would
+ simply display composite for grayscale images but do composition
+ with the incorrect arithmetic for color ones). In 1.6 the semantic
+ of -DPNG_NO_READ_GAMMA is changed to simply disable any interface that
+ depends on it; this obliges people who set it to consider whether they
+ really want it off if they happen to use any of the interfaces in
+ question (typically most users who disable it won't).
+ Fixed GUIDs in projects/vstudio. Some were duplicated or missing,
+ resulting in VS2010 having to update the files.
+ Removed non-working ICC profile support code that was mostly added to
+ libpng-1.6.0beta29 and beta30. There was too much code for too little
+ gain; implementing full ICC color correction may be desirable but is left
+ up to applications.
+
+Version 1.6.0beta32 [November 25, 2012]
+ Fixed an intermittent SEGV in pngstest due to an uninitialized array element.
+ Added the ability for contrib/libtests/makepng.c to make a PNG with just one
+ color. This is useful for debugging pngstest color inaccuracy reports.
+ Fixed error checking in the simplified write API (Olaf van der Spek)
+ Made png_user_version_check() ok to use with libpng version 1.10.x and later.
+
+Version 1.6.0beta33 [December 15, 2012]
+ Fixed typo in png.c (PNG_SET_CHUNK_MALLOC_MAX should be PNG_CHUNK_MALLOC_MAX)
+ that causes the MALLOC_MAX limit not to work (John Bowler)
+ Change png_warning() to png_app_error() in pngwrite.c and comment the
+ fall-through condition.
+ Change png_warning() to png_app_warning() in png_write_tRNS().
+ Rearranged the ARM-NEON optimizations: Isolated the machine specific code
+ to the hardware subdirectory and added comments to pngrutil.c so that
+ implementors of other optimizations know what to do.
+ Fixed cases of unquoted DESTDIR in Makefile.am
+ Rebuilt Makefile.in, etc., with autoconf-2.69 and automake-1.12.5.
+
+Version 1.6.0beta34 [December 19, 2012]
+ Cleaned up whitespace in the synopsis portion of the manpage "libpng.3"
+ Disassembled the version number in scripts/options.awk (necessary for
+ building on SunOs).
+
+Version 1.6.0beta35 [December 23, 2012]
+ Made default Zlib compression settings be configurable. This adds #defines to
+ pnglibconf.h to control the defaults.
+ Fixed Windows build issues, enabled ARM compilation. Various warnings issued
+ by earlier versions of GCC fixed for Cygwin and Min/GW (which both use old
+ GCCs.) ARM support is enabled by default in zlib.props (unsupported by
+ Microsoft) and ARM compilation is made possible by deleting the check for
+ x86. The test programs cannot be run because they are not signed.
+
+Version 1.6.0beta36 [January 2, 2013]
+ Discontinued distributing libpng-1.x.x.tar.bz2.
+ Discontinued distributing libpng-1.7.0-1.6.0-diff.txt and similar.
+ Rebuilt configure with autoconf-2.69 (inadvertently not done in beta33)
+ Fixed 'make distcheck' on SUN OS - libpng.so was not being removed
+
+Version 1.6.0beta37 [January 10, 2013]
+ Fixed conceivable but difficult to repro overflow. Also added two test
+ programs to generate and test a PNG which should have the problem.
+
+Version 1.6.0beta39 [January 19, 2013]
+ Again corrected attempt at overflow detection in png_set_unknown_chunks()
+ (CVE-2013-7353). Added overflow detection in png_set_sPLT() and
+ png_set_text_2() (CVE-2013-7354).
+
+Version 1.6.0beta40 [January 20, 2013]
+ Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs
+
+Version 1.6.0rc01 [January 26, 2013]
+ No changes.
+
+Version 1.6.0rc02 [February 4, 2013]
+ Added png_get_palette_max() function.
+
+Version 1.6.0rc03 [February 5, 2013]
+ Fixed the png_get_palette_max API.
+
+Version 1.6.0rc04 [February 7, 2013]
+ Turn serial tests back on (recently turned off by autotools upgrade).
+
+Version 1.6.0rc05 [February 8, 2013]
+ Update manual about png_get_palette_max().
+
+Version 1.6.0rc06 [February 9, 2013]
+ Fixed missing dependency in --prefix builds The intermediate
+ internal 'prefix.h' file can only be generated correctly after
+ pnglibconf.h, however the dependency was not in Makefile.am. The
+ symptoms are unpredictable depending on the order make chooses to
+ build pngprefix.h and pnglibconf.h, often the error goes unnoticed
+ because there is a system pnglibconf.h to use instead.
+
+Version 1.6.0rc07 [February 10, 2013]
+ Enclosed the new png_get_palette_max in #ifdef PNG_GET_PALETTE_MAX_SUPPORTED
+ block, and revised pnglibconf.h and pnglibconf.h.prebuilt accordingly.
+
+Version 1.6.0rc08 [February 10, 2013]
+ Fix typo in png.h #ifdef
+
+Version 1.6.0 [February 14, 2013]
+ No changes.
+
+Version 1.6.1beta01 [February 16, 2013]
+ Made symbol prefixing work with the ARM neon optimizations. Also allow
+ pngpriv.h to be included for preprocessor definitions only, so it can
+ be used in non-C/C++ files. Back ported from libpng 1.7.
+ Made sRGB check numbers consistent.
+ Ported libpng 1.5 options.awk/dfn file handling to 1.6, fixed one bug.
+ Removed cc -E workround, corrected png_get_palette_max API Tested on
+ SUN OS cc 5.9, which demonstrates the tokenization problem previously
+ avoided by using /lib/cpp. Since all .dfn output is now protected in
+ double quotes unless it is to be macro substituted the fix should
+ work everywhere.
+ Enabled parallel tests - back ported from libpng-1.7.
+ scripts/pnglibconf.dfa formatting improvements back ported from libpng17.
+ Fixed a race condition in the creation of the build 'scripts' directory
+ while building with a parallel make.
+ Use approved/supported Android method to check for NEON, use Linux/POSIX
+ 1003.1 API to check /proc/self/auxv avoiding buffer allocation and other
+ library calls (ported from libpng15).
+
+Version 1.6.1beta02 [February 19, 2013]
+ Use parentheses more consistently in "#if defined(MACRO)" tests.
+ Folded long lines.
+ Reenabled code to allow zero length PLTE chunks for MNG.
+
+Version 1.6.1beta03 [February 22, 2013]
+ Fixed ALIGNED_MEMORY support.
+ Added a new configure option:
+ --enable-arm-neon=always will stop the run-time checks. New checks
+ within arm/arm_init.c will cause the code not to be compiled unless
+ __ARM_NEON__ is set. This should make it fail safe (if someone asks
+ for it on then the build will fail if it can't be done.)
+ Updated the INSTALL document.
+
+Version 1.6.1beta04 [February 27, 2013]
+ Revised INSTALL to recommend using CPPFLAGS instead of INCLUDES.
+ Revised scripts/makefile.freebsd to respect ZLIBLIB and ZLIBINC.
+ Revised scripts/dfn.awk to work with the buggy MSYS awk that has trouble
+ with CRLF line endings.
+
+Version 1.6.1beta05 [March 1, 2013]
+ Avoid a possible memory leak in contrib/gregbook/readpng.c
+
+Version 1.6.1beta06 [March 4, 2013]
+ Better documentation of unknown handling API interactions.
+ Corrected Android builds and corrected libpng.vers with symbol
+ prefixing. It also makes those tests compile and link on Android.
+ Added an API png_set_option() to set optimization options externally,
+ providing an alternative and general solution for the non-portable
+ run-time tests used by the ARM Neon code, using the PNG_ARM_NEON option.
+ The order of settings vs options in pnglibconf.h is reversed to allow
+ settings to depend on options and options can now set (or override) the
+ defaults for settings.
+
+Version 1.6.1beta07 [March 7, 2013]
+ Corrected simplified API default gamma for color-mapped output, added
+ a flag to change default. In 1.6.0 when the simplified API was used
+ to produce color-mapped output from an input image with no gamma
+ information the gamma assumed for the input could be different from
+ that assumed for non-color-mapped output. In particular 16-bit depth
+ input files were assumed to be sRGB encoded, whereas in the 'direct'
+ case they were assumed to have linear data. This was an error. The
+ fix makes the simplified API treat all input files the same way and
+ adds a new flag to the png_image::flags member to allow the
+ application/user to specify that 16-bit files contain sRGB data
+ rather than the default linear.
+ Fixed bugs in the pngpixel and makepng test programs.
+
+Version 1.6.1beta08 [March 7, 2013]
+ Fixed CMakelists.txt to allow building a single variant of the library
+ (Claudio Bley):
+ Introduced a PNG_LIB_TARGETS variable that lists all activated library
+ targets. It is an error if this variable ends up empty, ie. you have
+ to build at least one library variant.
+ Made the *_COPY targets only depend on library targets actually being build.
+ Use PNG_LIB_TARGETS to unify a code path.
+ Changed the CREATE_SYMLINK macro to expect the full path to a file as the
+ first argument. When symlinking the filename component of that path is
+ determined and used as the link target.
+ Use copy_if_different in the CREATE_SYMLINK macro.
+
+Version 1.6.1beta09 [March 13, 2013]
+ Eliminated two warnings from the Intel C compiler. The warnings are
+ technically valid, although a reasonable treatment of division would
+ show it to be incorrect.
+
+Version 1.6.1rc01 [March 21, 2013]
+ No changes.
+
+Version 1.6.1 [March 28, 2013]
+ No changes.
+
+Version 1.6.2beta01 [April 14, 2013]
+ Updated documentation of 1.5.x to 1.6.x changes in iCCP chunk handling.
+ Fixed incorrect warning of excess deflate data. End condition - the
+ warning would be produced if the end of the deflate stream wasn't read
+ in the last row. The warning is harmless.
+ Corrected the test on user transform changes on read. It was in the
+ png_set of the transform function, but that doesn't matter unless the
+ transform function changes the rowbuf size, and that is only valid if
+ transform_info is called.
+ Corrected a misplaced closing bracket in contrib/libtests/pngvalid.c
+ (Flavio Medeiros).
+ Corrected length written to uncompressed iTXt chunks (Samuli Suominen).
+ Bug was introduced in libpng-1.6.0.
+
+Version 1.6.2rc01 [April 18, 2013]
+ Added contrib/tools/fixitxt.c, to repair the erroneous iTXt chunk length
+ written by libpng-1.6.0 and 1.6.1.
+ Disallow storing sRGB information when the sRGB is not supported.
+
+Version 1.6.2rc02 [April 18, 2013]
+ Merge pngtest.c with libpng-1.7.0
+
+Version 1.6.2rc03 [April 22, 2013]
+ Trivial spelling cleanup.
+
+Version 1.6.2rc04 and 1.6.2rc05 [omitted]
+
+Version 1.6.2rc06 [April 24, 2013]
+ Reverted to version 1.6.2rc03. Recent changes to arm/neon support
+ have been ported to libpng-1.7.0beta09 and will reappear in version
+ 1.6.3beta01.
+
+Version 1.6.2 [April 25, 2013]
+ No changes.
+
+Version 1.6.3beta01 [April 25, 2013]
+ Revised stack marking in arm/filter_neon.S and configure.ac.
+ Ensure that NEON filter stuff is completely disabled when switched 'off'.
+ Previously the ARM NEON specific files were still built if the option
+ was switched 'off' as opposed to being explicitly disabled.
+
+Version 1.6.3beta02 [April 26, 2013]
+ Test for 'arm*' not just 'arm' in the host_cpu configure variable.
+ Rebuilt the configure scripts.
+
+Version 1.6.3beta03 [April 30, 2013]
+ Expanded manual paragraph about writing private chunks, particularly
+ the need to call png_set_keep_unknown_chunks() when writing them.
+ Avoid dereferencing NULL pointer possibly returned from
+ png_create_write_struct() (Andrew Church).
+
+Version 1.6.3beta05 [May 9, 2013]
+ Calculate our own zlib windowBits when decoding rather than trusting the
+ CMF bytes in the PNG datastream.
+ Added an option to force maximum window size for inflating, which was
+ the behavior of libpng15 and earlier, via a new PNG_MAXIMUM_INFLATE_WINDOW
+ option for png_set_options().
+ Added png-fix-itxt and png-fix-too-far-back to the built programs and
+ removed warnings from the source code and timepng that are revealed as
+ a result.
+ Detect wrong libpng versions linked to png-fix-too-far-back, which currently
+ only works with libpng versions that can be made to reliably fail when
+ the deflate data contains an out-of-window reference. This means only
+ 1.6 and later.
+ Fixed gnu issues: g++ needs a static_cast, gcc 4.4.7 has a broken warning
+ message which it is easier to work round than ignore.
+ Updated contrib/pngminus/pnm2png.c (Paul Stewart):
+ Check for EOF
+ Ignore "#" delimited comments in input file to pnm2png.c.
+ Fixed whitespace handling
+ Added a call to png_set_packing()
+ Initialize dimension values so if sscanf fails at least we have known
+ invalid values.
+ Attempt to detect configuration issues with png-fix-too-far-back, which
+ requires both the correct libpng and the correct zlib to function
+ correctly.
+ Check ZLIB_VERNUM for mismatches, enclose #error in quotes
+ Added information in the documentation about problems with and fixes for
+ the bad CRC and bad iTXt chunk situations.
+
+Version 1.6.3beta06 [May 12, 2013]
+ Allow contrib/pngminus/pnm2png.c to compile without WRITE_INVERT and
+ WRITE_PACK supported (writes error message that it can't read P1 or
+ P4 PBM files).
+ Improved png-fix-too-far-back usage message, added --suffix option.
+ Revised contrib/pngminim/*/makefile to generate pnglibconf.h with the
+ right zlib header files.
+ Separated CPPFLAGS and CFLAGS in contrib/pngminim/*/makefile
+
+Version 1.6.3beta07 [June 8, 2013]
+ Removed a redundant test in png_set_IHDR().
+ Added set(CMAKE_CONFIGURATION_TYPES ...) to CMakeLists.txt (Andrew Hundt)
+ Deleted set(CMAKE_BUILD_TYPE) block from CMakeLists.txt
+ Enclose the prototypes for the simplified write API in
+ #ifdef PNG_STDIO_SUPPORTED/#endif
+ Make ARM NEON support work at compile time (not just configure time).
+ This moves the test on __ARM_NEON__ into pngconf.h to avoid issues when
+ using a compiler that compiles for multiple architectures at one time.
+ Removed PNG_FILTER_OPTIMIZATIONS and PNG_ARM_NEON_SUPPORTED from
+ pnglibconf.h, allowing more of the decisions to be made internally
+ (pngpriv.h) during the compile. Without this, symbol prefixing is broken
+ under certain circumstances on ARM platforms. Now only the API parts of
+ the optimizations ('check' vs 'api') are exposed in the public header files
+ except that the new setting PNG_ARM_NEON_OPT documents how libpng makes the
+ decision about whether or not to use the optimizations.
+ Protect symbol prefixing against CC/CPPFLAGS/CFLAGS usage.
+ Previous iOS/Xcode fixes for the ARM NEON optimizations moved the test
+ on __ARM_NEON__ from configure time to compile time. This breaks symbol
+ prefixing because the definition of the special png_init_filter_functions
+ call was hidden at configure time if the relevant compiler arguments are
+ passed in CFLAGS as opposed to CC. This change attempts to avoid all
+ the confusion that would result by declaring the init function even when
+ it is not used, so that it will always get prefixed.
+
+Version 1.6.3beta08 [June 18, 2013]
+ Revised libpng.3 so that "doclifter" can process it.
+
+Version 1.6.3beta09 [June 27, 2013]
+ Revised example.c to illustrate use of PNG_DEFAULT_sRGB and PNG_GAMMA_MAC_18
+ as parameters for png_set_gamma(). These have been available since
+ libpng-1.5.4.
+ Renamed contrib/tools/png-fix-too-far-back.c to pngfix.c and revised it
+ to check all compressed chunks known to libpng.
+
+Version 1.6.3beta10 [July 5, 2013]
+ Updated documentation to show default behavior of benign errors correctly.
+ Only compile ARM code when PNG_READ_SUPPORTED is defined.
+ Fixed undefined behavior in contrib/tools/pngfix.c and added new strip
+ option. pngfix relied on undefined behavior and even a simple change from
+ gcc to g++ caused it to fail. The new strip option 'unsafe' has been
+ implemented and is the default if --max is given. Option names have
+ been clarified, with --strip=transform now stripping the bKGD chunk,
+ which was stripped previously with --strip=unused.
+ Added all documented chunk types to pngpriv.h
+ Unified pngfix.c source with libpng17.
+
+Version 1.6.3rc01 [July 11, 2013]
+ No changes.
+
+Version 1.6.3 [July 18, 2013]
+ Revised manual about changes in iTXt chunk handling made in libpng-1.6.0.
+ Added "/* SAFE */" comments in pngrutil.c and pngrtran.c where warnings
+ may be erroneously issued by code-checking applications.
+
+Version 1.6.4beta01 [August 21, 2013]
+ Added information about png_set_options() to the manual.
+ Delay calling png_init_filter_functions() until a row with nonzero filter
+ is found.
+
+Version 1.6.4beta02 [August 30, 2013]
+ Fixed inconsistent conditional compilation of png_chunk_unknown_handling()
+ prototype, definition, and usage. Made it depend on
+ PNG_HANDLE_AS_UNKNOWN_SUPPORTED everywhere.
+
+Version 1.6.4rc01 [September 5, 2013]
+ No changes.
+
+Version 1.6.4 [September 12, 2013]
+ No changes.
+
+Version 1.6.5 [September 14, 2013]
+ Removed two stray lines of code from arm/arm_init.c.
+
+Version 1.6.6 [September 16, 2013]
+ Removed two stray lines of code from arm/arm_init.c, again.
+
+Version 1.6.7beta01 [September 30, 2013]
+ Revised unknown chunk code to correct several bugs in the NO_SAVE_/NO_WRITE
+ combination
+ Allow HANDLE_AS_UNKNOWN to work when other options are configured off. Also
+ fixed the pngminim makefiles to work when $(MAKEFLAGS) contains stuff
+ which terminates the make options (as by default in recent versions of
+ Gentoo).
+ Avoid up-cast warnings in pngvalid.c. On ARM the alignment requirements of
+ png_modifier are greater than that of png_store and as a consequence
+ compilation of pngvalid.c results in a warning about increased alignment
+ requirements because of the bare cast to (png_modifier*). The code is safe,
+ because the pointer is known to point to a stack allocated png_modifier,
+ but this change avoids the warning.
+ Fixed default behavior of ARM_NEON_API. If the ARM NEON API option was
+ compiled without the CHECK option it defaulted to on, not off.
+ Check user callback behavior in pngunknown.c. Previous versions compiled
+ if SAVE_UNKNOWN was not available but did nothing since the callback
+ was never implemented.
+ Merged pngunknown.c with 1.7 version and back ported 1.7 improvements/fixes
+
+Version 1.6.7beta02 [October 12, 2013]
+ Made changes for compatibility with automake 1.14:
+ 1) Added the 'compile' program to the list of programs that must be cleaned
+ in autogen.sh
+ 2) Added 'subdir-objects' which causes .c files in sub-directories to be
+ compiled such that the corresponding .o files are also in the
+ sub-directory. This is because automake 1.14 warns that the
+ current behavior of compiling to the top level directory may be removed
+ in the future.
+ 3) Updated dependencies on pnglibconf.h to match the new .o locations and
+ added all the files in contrib/libtests and contrib/tools that depend
+ on pnglibconf.h
+ 4) Added 'BUILD_SOURCES = pnglibconf.h'; this is the automake recommended
+ way of handling the dependencies of sources that are machine generated;
+ unfortunately it only works if the user does 'make all' or 'make check',
+ so the dependencies (3) are still required.
+ Cleaned up (char*) casts of zlib messages. The latest version of the Intel C
+ compiler complains about casting a string literal as (char*), so copied the
+ treatment of z_const from the library code into pngfix.c
+ Simplified error message code in pngunknown. The simplification has the
+ useful side effect of avoiding a bogus warning generated by the latest
+ version of the Intel C compiler (it objects to
+ condition ? string-literal : string-literal).
+ Make autogen.sh work with automake 1.13 as well as 1.14. Do this by always
+ removing the 1.14 'compile' script but never checking for it.
+
+Version 1.6.7beta03 [October 19, 2013]
+ Added ARMv8 support (James Yu <james.yu at linaro.org>). Added file
+ arm/filter_neon_intrinsics.c; enable with -mfpu=neon.
+ Revised pngvalid to generate size images with as many filters as it can
+ manage, limited by the number of rows.
+ Cleaned up ARM NEON compilation handling. The tests are now in pngpriv.h
+ and detect the broken GCC compilers.
+
+Version 1.6.7beta04 [October 26, 2013]
+ Allow clang derived from older GCC versions to use ARM intrinsics. This
+ causes all clang builds that use -mfpu=neon to use the intrinsics code,
+ not the assembler code. This has only been tested on iOS 7. It may be
+ necessary to exclude some earlier clang versions but this seems unlikely.
+ Changed NEON implementation selection mechanism. This allows assembler
+ or intrinsics to be turned on at compile time during the build by defining
+ PNG_ARM_NEON_IMPLEMENTATION to the correct value (2 or 1). This macro
+ is undefined by default and the build type is selected in pngpriv.h.
+
+Version 1.6.7rc01 [November 2, 2013]
+ No changes.
+
+Version 1.6.7rc02 [November 7, 2013]
+ Fixed #include in filter_neon_intrinsics.c and ctype macros. The ctype char
+ checking macros take an unsigned char argument, not a signed char.
+
+Version 1.6.7 [November 14, 2013]
+ No changes.
+
+Version 1.6.8beta01 [November 24, 2013]
+ Moved prototype for png_handle_unknown() in pngpriv.h outside of
+ the #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED/#endif block.
+ Added "-Wall" to CFLAGS in contrib/pngminim/*/makefile
+ Conditionally compile some unused functions reported by -Wall in
+ pngminim.
+ Fixed 'minimal' builds. Various obviously useful minimal configurations
+ don't build because of missing contrib/libtests test programs and
+ overly complex dependencies in scripts/pnglibconf.dfa. This change
+ adds contrib/conftest/*.dfa files that can be used in automatic build
+ scripts to ensure that these configurations continue to build.
+ Enabled WRITE_INVERT and WRITE_PACK in contrib/pngminim/encoder.
+ Fixed pngvalid 'fail' function declaration on the Intel C Compiler.
+ This reverts to the previous 'static' implementation and works round
+ the 'unused static function' warning by using PNG_UNUSED().
+
+Version 1.6.8beta02 [November 30, 2013]
+ Removed or marked PNG_UNUSED some harmless "dead assignments" reported
+ by clang scan-build.
+ Changed tabs to 3 spaces in png_debug macros and changed '"%s"m'
+ to '"%s" m' to improve portability among compilers.
+ Changed png_free_default() to free() in pngtest.c
+
+Version 1.6.8rc01 [December 12, 2013]
+ Tidied up pngfix inits and fixed pngtest no-write builds.
+
+Version 1.6.8rc02 [December 14, 2013]
+ Handle zero-length PLTE chunk or NULL palette with png_error()
+ instead of png_chunk_report(), which by default issues a warning
+ rather than an error, leading to later reading from a NULL pointer
+ (png_ptr->palette) in png_do_expand_palette(). This is CVE-2013-6954
+ and VU#650142. Libpng-1.6.1 through 1.6.7 are vulnerable.
+ Libpng-1.6.0 and earlier do not have this bug.
+
+Version 1.6.8 [December 19, 2013]
+ No changes.
+
+Version 1.6.9beta01 [December 26, 2013]
+ Bookkeeping: Moved functions around (no changes). Moved transform
+ function definitions before the place where they are called so that
+ they can be made static. Move the intrapixel functions and the
+ grayscale palette builder out of the png?tran.c files. The latter
+ isn't a transform function and is no longer used internally, and the
+ former MNG specific functions are better placed in pngread/pngwrite.c
+ Made transform implementation functions static. This makes the internal
+ functions called by png_do_{read|write}_transformations static. On an
+ x86-64 DLL build (Gentoo Linux) this reduces the size of the text
+ segment of the DLL by 1208 bytes, about 0.6%. It also simplifies
+ maintenance by removing the declarations from pngpriv.h and allowing
+ easier changes to the internal interfaces.
+ Rebuilt configure scripts with automake-1.14.1 and autoconf-2.69
+ in the tar distributions.
+
+Version 1.6.9beta02 [January 1, 2014]
+ Added checks for libpng 1.5 to pngvalid.c. This supports the use of
+ this version of pngvalid in libpng 1.5
+ Merged with pngvalid.c from libpng-1.7 changes to create a single
+ pngvalid.c
+ Removed #error macro from contrib/tools/pngfix.c (Thomas Klausner).
+ Merged pngrio.c, pngtrans.c, pngwio.c, and pngerror.c with libpng-1.7.0
+ Merged libpng-1.7.0 changes to make no-interlace configurations work
+ with test programs.
+ Revised pngvalid.c to support libpng 1.5, which does not support the
+ PNG_MAXIMUM_INFLATE_WINDOW option, so #define it out when appropriate in
+ pngvalid.c
+ Allow unversioned links created on install to be disabled in configure.
+ In configure builds 'make install' changes/adds links like png.h
+ and libpng.a to point to the newly installed, versioned, files (e.g.
+ libpng17/png.h and libpng17.a). Three new configure options and some
+ rearrangement of Makefile.am allow creation of these links to be disabled.
+
+Version 1.6.9beta03 [January 10, 2014]
+ Removed potentially misleading warning from png_check_IHDR().
+
+Version 1.6.9beta04 [January 20, 2014]
+ Updated scripts/makefile.* to use CPPFLAGS (Cosmin).
+ Added clang attribute support (Cosmin).
+
+Version 1.6.9rc01 [January 28, 2014]
+ No changes.
+
+Version 1.6.9rc02 [January 30, 2014]
+ Quiet an uninitialized memory warning from VC2013 in png_get_png().
+
+Version 1.6.9 [February 6, 2014]
+
+Version 1.6.10beta01 [February 9, 2014]
+ Backported changes from libpng-1.7.0beta30 and beta31:
+ Fixed a large number of instances where PNGCBAPI was omitted from
+ function definitions.
+ Added pngimage test program for png_read_png() and png_write_png()
+ with two new test scripts.
+ Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
+ png_set_packing() in png_read_png().
+ Fixed combination of ~alpha with shift. On read invert alpha, processing
+ occurred after shift processing, which causes the final values to be
+ outside the range that should be produced by the shift. Reversing the
+ order on read makes the two transforms work together correctly and mirrors
+ the order used on write.
+ Do not read invalid sBIT chunks. Previously libpng only checked sBIT
+ values on write, so a malicious PNG writer could therefore cause
+ the read code to return an invalid sBIT chunk, which might lead to
+ application errors or crashes. Such chunks are now skipped (with
+ chunk_benign_error).
+ Make png_read_png() and png_write_png() prototypes in png.h depend
+ upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
+ Support builds with unsupported PNG_TRANSFORM_* values. All of the
+ PNG_TRANSFORM_* values are always defined in png.h and, because they
+ are used for both read and write in some cases, it is not reliable
+ to #if out ones that are totally unsupported. This change adds error
+ detection in png_read_image() and png_write_image() to do a
+ png_app_error() if the app requests something that cannot be done
+ and it adds corresponding code to pngimage.c to handle such options
+ by not attempting to test them.
+
+Version 1.6.10beta02 [February 23, 2014]
+ Moved redefines of png_error(), png_warning(), png_chunk_error(),
+ and png_chunk_warning() from pngpriv.h to png.h to make them visible
+ to libpng-calling applications.
+ Moved OS dependent code from arm/arm_init.c, to allow the included
+ implementation of the ARM NEON discovery function to be set at
+ build-time and provide sample implementations from the current code in the
+ contrib/arm-neon subdirectory. The __linux__ code has also been changed to
+ compile and link on Android by using /proc/cpuinfo, and the old linux code
+ is in contrib/arm-neon/linux-auxv.c. The new code avoids POSIX and Linux
+ dependencies apart from opening /proc/cpuinfo and is C90 compliant.
+ Check for info_ptr == NULL early in png_read_end() so we don't need to
+ run all the png_handle_*() and depend on them to return if info_ptr == NULL.
+ This improves the performance of png_read_end(png_ptr, NULL) and makes
+ it more robust against future programming errors.
+ Check for __has_extension before using it in pngconf.h, to
+ support older Clang versions (Jeremy Sequoia).
+ Treat CRC error handling with png_set_crc_action(), instead of with
+ png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
+ Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
+ so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
+ Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
+ after recognizing the IDAT chunk, which avoids an infinite loop while
+ reading a datastream whose first IDAT chunk is of zero-length.
+ This fixes CERT VU#684412 and CVE-2014-0333.
+ Don't recognize known sRGB profiles as sRGB if they have been hacked,
+ but don't reject them and don't issue a copyright violation warning.
+
+Version 1.6.10beta03 [February 25, 2014]
+ Moved some documentation from png.h to libpng.3 and libpng-manual.txt
+ Minor editing of contrib/arm-neon/README and contrib/examples/*.c
+
+Version 1.6.10rc01 [February 27, 2014]
+ Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
+ and PNG_USR_CONFIG -> PNG_USER_CONFIG).
+
+Version 1.6.10rc02 [February 28, 2014]
+ Removed unreachable return statement after png_chunk_error()
+ in pngrutil.c
+
+Version 1.6.10rc03 [March 4, 2014]
+ Un-deprecated png_data_freer().
+
+Version 1.6.10 [March 6, 2014]
+ No changes.
+
+Version 1.6.11beta01 [March 17, 2014]
+ Use "if (value != 0)" instead of "if (value)" consistently.
+ Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
+ Moved configuration information from the manual to the INSTALL file.
+
+Version 1.6.11beta02 [April 6, 2014]
+ Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
+ they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
+ when using its "__builtin_pow()" function.
+ Silence 'unused parameter' build warnings (Cosmin Truta).
+ $(CP) is now used alongside $(RM_F). Also, use 'copy' instead of 'cp'
+ where applicable, and applied other minor makefile changes (Cosmin).
+ Don't warn about invalid dimensions exceeding user limits (Cosmin).
+ Allow an easy replacement of the default pre-built configuration
+ header with a custom header, via the make PNGLIBCONF_H_PREBUILT
+ macro (Cosmin).
+
+Version 1.6.11beta03 [April 6, 2014]
+ Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
+ with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
+ Optionally use __builtin_bswap16() in png_do_swap().
+
+Version 1.6.11beta04 [April 19, 2014]
+ Made progressive reading of interlaced images consistent with the
+ behavior of the sequential reader and consistent with the manual, by
+ moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
+ row_callback now receives the proper pass number and unexpanded rows, when
+ png_combine_row() isn't built or used, and png_set_interlace_handling()
+ is not called.
+ Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
+
+Version 1.6.11beta05 [April 26, 2014]
+ Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
+ Relocated closing bracket of the sRGB profile test loop to avoid getting
+ "Not recognizing known sRGB profile that has been edited" warning for
+ ICC V2 profiles that lack the MD5 signature in the profile header.
+
+Version 1.6.11beta06 [May 19, 2014]
+ Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
+
+Version 1.6.11rc01 [May 27, 2014]
+ No changes.
+
+Version 1.6.11rc02 [June 3, 2014]
+ Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
+
+Version 1.6.11 [June 5, 2014]
+ No changes.
+
+Version 1.6.12rc01 [June 6, 2014]
+ Relocated new code from 1.6.11beta06 in png.c to a point after the
+ declarations (Max Stepin).
+
+Version 1.6.12rc02 [June 7, 2014]
+ Changed file permissions of contrib/tools/intgamma.sh,
+ test-driver, and compile from 0644 to 0755 (Cosmin).
+
+Version 1.6.12rc03 [June 8, 2014]
+ Ensure "__has_attribute()" macro exists before trying to use it with
+ old clang compilers (MacPorts Ticket #43939).
+
+Version 1.6.12 [June 12, 2014]
+ No changes.
+
+Version 1.6.13beta01 [July 4, 2014]
+ Quieted -Wsign-compare and -Wclobber compiler warnings in
+ contrib/pngminus/*.c
+ Added "(void) png_ptr;" where needed in contrib/gregbook to quiet
+ compiler complaints about unused pointers.
+ Split a long output string in contrib/gregbook/rpng2-x.c.
+ Added "PNG_SET_OPTION" requirement for sRGB chunk support to pnglibconf.dfa,
+ Needed for write-only support (John Bowler).
+ Changed "if defined(__ARM_NEON__)" to
+ "if (defined(__ARM_NEON__) || defined(__ARM_NEON))" (James Wu).
+ Fixed clang no-warning builds: png_digit was defined but never used.
+
+Version 1.6.13beta02 [July 21, 2014]
+ Fixed an incorrect separator ("/" should be "\") in scripts/makefile.vcwin32
+ (bug report from Wolfgang S. Kechel). Bug was introduced in libpng-1.6.11.
+ Also fixed makefile.bc32, makefile.bor, makefile.msc, makefile.intel, and
+ makefile.tc3 similarly.
+
+Version 1.6.13beta03 [August 3, 2014]
+ Removed scripts/makefile.elf. It has not worked since libpng-1.5.0beta14
+ due to elimination of the PNG_FUNCTION_EXPORT and PNG_DATA_EXPORT
+ definitions from pngconf.h.
+ Ensure that CMakeLists.txt makes the target "lib" directory before making
+ symbolic link into it (SourceForge bug report #226 by Rolf Timmermans).
+
+Version 1.6.13beta04 [August 8, 2014]
+ Added opinion that the ECCN (Export Control Classification Number) for
+ libpng is EAR99 to the README file.
+ Eliminated use of "$<" in makefile explicit rules, when copying
+ $PNGLIBCONF_H_PREBUILT. This does not work on some versions of make;
+ bug introduced in libpng version 1.6.11.
+
+Version 1.6.13rc01 [August 14, 2014]
+ Made "ccopts" agree with "CFLAGS" in scripts/makefile.hp* and makefile.*sunu
+
+Version 1.6.13 [August 21, 2014]
+ No changes.
+
+Version 1.6.14beta01 [September 14, 2014]
+ Guard usage of png_ptr->options with #ifdef PNG_SET_OPTION_SUPPORTED.
+ Do not build contrib/tools/pngfix.c when PNG_SETJMP_NOT_SUPPORTED,
+ to allow "make" to complete without setjmp support (bug report by
+ Claudio Fontana)
+ Add "#include <setjmp.h>" to contrib/tools/pngfix.c (John Bowler)
+
+Version 1.6.14beta02 [September 18, 2014]
+ Use nanosleep() instead of usleep() in contrib/gregbook/rpng2-x.c
+ because usleep() is deprecated.
+ Define usleep() in contrib/gregbook/rpng2-x.c if not already defined
+ in unistd.h and nanosleep() is not available; fixes error introduced
+ in libpng-1.6.13.
+ Disable floating point exception handling in pngvalid.c when
+ PNG_FLOATING_ARITHMETIC is not supported (bug report by "zootus
+ at users.sourceforge.net").
+
+Version 1.6.14beta03 [September 19, 2014]
+ Define FE_DIVBYZERO, FE_INVALID, and FE_OVERFLOW in pngvalid.c if not
+ already defined. Revert floating point exception handling in pngvalid.c
+ to version 1.6.14beta01 behavior.
+
+Version 1.6.14beta04 [September 27, 2014]
+ Fixed incorrect handling of the iTXt compression flag in pngrutil.c
+ (bug report by Shunsaku Hirata). Bug was introduced in libpng-1.6.0.
+
+Version 1.6.14beta05 [October 1, 2014]
+ Added "option READ_iCCP enables READ_COMPRESSED_TEXT" to pnglibconf.dfa
+
+Version 1.6.14beta06 [October 5, 2014]
+ Removed unused "text_len" parameter from private function png_write_zTXt().
+ Conditionally compile some code in png_deflate_claim(), when
+ PNG_WARNINGS_SUPPORTED and PNG_ERROR_TEXT_SUPPORTED are disabled.
+ Replaced repeated code in pngpread.c with PNG_PUSH_SAVE_BUFFER_IF_FULL.
+ Added "chunk iTXt enables TEXT" and "chunk zTXt enables TEXT"
+ to pnglibconf.dfa.
+ Removed "option READ_COMPRESSED_TEXT enables READ_TEXT" from pnglibconf.dfa,
+ to make it possible to configure a libpng that supports iCCP but not TEXT.
+
+Version 1.6.14beta07 [October 7, 2014]
+ Removed "option WRITE_COMPRESSED_TEXT enables WRITE_TEXT" from pnglibconf.dfa
+ Only mark text chunks as written after successfully writing them.
+
+Version 1.6.14rc01 [October 15, 2014]
+ Fixed some typos in comments.
+
+Version 1.6.14rc02 [October 17, 2014]
+ Changed png_convert_to_rfc_1123() to png_convert_to_rfc_1123_buffer()
+ in the manual, to reflect the change made in libpng-1.6.0.
+ Updated README file to explain that direct access to the png_struct
+ and info_struct members has not been permitted since libpng-1.5.0.
+
+Version 1.6.14 [October 23, 2014]
+ No changes.
+
+Version 1.6.15beta01 [October 29, 2014]
+ Changed "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+ Simplified png_free_data().
+ Added missing "ptr = NULL" after some instances of png_free().
+
+Version 1.6.15beta02 [November 1, 2014]
+ Changed remaining "if (!x)" to "if (x == 0)" and "if (x)" to "if (x != 0)"
+
+Version 1.6.15beta03 [November 3, 2014]
+ Added PNG_USE_ARM_NEON configuration flag (Marcin Juszkiewicz).
+
+Version 1.6.15beta04 [November 4, 2014]
+ Removed new PNG_USE_ARM_NEON configuration flag and made a one-line
+ revision to configure.ac to support ARM on aarch64 instead (John Bowler).
+
+Version 1.6.15beta05 [November 5, 2014]
+ Use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING in
+ example.c, pngtest.c, and applications in the contrib directory.
+ Fixed an out-of-range read in png_user_version_check() (Bug report from
+ Qixue Xiao, CVE-2015-8540).
+ Simplified and future-proofed png_user_version_check().
+ Fixed GCC unsigned int->float warnings. Various versions of GCC
+ seem to generate warnings when an unsigned value is implicitly
+ converted to double. This is probably a GCC bug but this change
+ avoids the issue by explicitly converting to (int) where safe.
+ Free all allocated memory in pngimage. The file buffer cache was left
+ allocated at the end of the program, harmless but it causes memory
+ leak reports from clang.
+ Fixed array size calculations to avoid warnings. At various points
+ in the code the number of elements in an array is calculated using
+ sizeof. This generates a compile time constant of type (size_t) which
+ is then typically assigned to an (unsigned int) or (int). Some versions
+ of GCC on 64-bit systems warn about the apparent narrowing, even though
+ the same compiler does apparently generate the correct, in-range,
+ numeric constant. This adds appropriate, safe, casts to make the
+ warnings go away.
+
+Version 1.6.15beta06 [November 6, 2014]
+ Reverted use png_get_libpng_ver(NULL) instead of PNG_LIBPNG_VER_STRING
+ in the manual, example.c, pngtest.c, and applications in the contrib
+ directory. It was incorrect advice.
+
+Version 1.6.15beta07 [November 7, 2014]
+ Removed #ifdef PNG_16BIT_SUPPORTED/#endif around png_product2(); it is
+ needed by png_reciprocal2().
+ Added #ifdef PNG_16BIT_SUPPORTED/#endif around png_log16bit() and
+ png_do_swap().
+ Changed all "#endif /* PNG_FEATURE_SUPPORTED */" to "#endif /* FEATURE */"
+
+Version 1.6.15beta08 [November 8, 2014]
+ More housecleaning in *.h
+
+Version 1.6.15rc01 [November 13, 2014]
+
+Version 1.6.15rc02 [November 14, 2014]
+ The macros passed in the command line to Borland make were ignored if
+ similarly-named macros were already defined in makefiles. This behavior
+ is different from POSIX make and other make programs. Surround the
+ macro definitions with ifndef guards (Cosmin).
+
+Version 1.6.15rc03 [November 16, 2014]
+ Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
+ Removed the obsolete $ARCH variable from scripts/makefile.darwin.
+
+Version 1.6.15 [November 20, 2014]
+ No changes.
+
+Version 1.6.16beta01 [December 14, 2014]
+ Added ".align 2" to arm/filter_neon.S to support old GAS assemblers that
+ don't do alignment correctly.
+ Revised Makefile.am and scripts/symbols.dfn to work with MinGW/MSYS
+ (Bob Friesenhahn).
+
+Version 1.6.16beta02 [December 15, 2014]
+ Revised Makefile.am and scripts/*.dfn again to work with MinGW/MSYS;
+ renamed scripts/*.dfn to scripts/*.c (John Bowler).
+
+Version 1.6.16beta03 [December 21, 2014]
+ Quiet a "comparison always true" warning in pngstest.c (John Bowler).
+
+Version 1.6.16rc01 [December 21, 2014]
+ Restored a test on width that was removed from png.c at libpng-1.6.9
+ (Bug report by Alex Eubanks, CVE-2015-0973).
+
+Version 1.6.16rc02 [December 21, 2014]
+ Undid the update to pngrutil.c in 1.6.16rc01.
+
+Version 1.6.16rc03 [December 21, 2014]
+ Fixed an overflow in png_combine_row() with very wide interlaced images
+ (Bug report and fix by John Bowler, CVE-2014-9495).
+
+Version 1.6.16 [December 22, 2014]
+ No changes.
+
+Version 1.6.17beta01 [January 29, 2015]
+ Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+ Corrected the width limit calculation in png_check_IHDR().
+ Removed user limits from pngfix. Also pass NULL pointers to
+ png_read_row to skip the unnecessary row de-interlace stuff.
+ Added testing of png_set_packing() to pngvalid.c
+ Regenerated configure scripts in the *.tar distributions with libtool-2.4.4
+ Implement previously untested cases of libpng transforms in pngvalid.c
+ Fixed byte order in png_do_read_filler() with 16-bit input. Previously
+ the high and low bytes of the filler, from png_set_filler() or from
+ png_set_add_alpha(), were read in the wrong order.
+ Made the check for out-of-range values in png_set_tRNS() detect
+ values that are exactly 2^bit_depth, and work on 16-bit platforms.
+ Merged some parts of libpng-1.6.17beta01 and libpng-1.7.0beta47.
+ Added #ifndef __COVERITY__ where needed in png.c, pngrutil.c and
+ pngset.c to avoid warnings about dead code.
+ Added "& 0xff" to many instances of expressions that are typecast
+ to (png_byte), to avoid Coverity warnings.
+
+Version 1.6.17beta02 [February 7, 2015]
+ Work around one more Coverity-scan dead-code warning.
+ Do not build png_product2() when it is unused.
+
+Version 1.6.17beta03 [February 17, 2015]
+ Display user limits in the output from pngtest.
+ Eliminated the PNG_SAFE_LIMITS macro and restored the 1-million-column
+ and 1-million-row default limits in pnglibconf.dfa, that can be reset
+ by the user at build time or run time. This provides a more robust
+ defense against DOS and as-yet undiscovered overflows.
+
+Version 1.6.17beta04 [February 21, 2015]
+ Added PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED macro, on by default.
+ Allow user to call png_get_IHDR() with NULL arguments (Reuben Hawkins).
+ Rebuilt configure scripts with automake-1.15 and libtool-2.4.6
+
+Version 1.6.17beta05 [February 25, 2015]
+ Restored compiling of png_reciprocal2 with PNG_NO_16BIT.
+
+Version 1.6.17beta06 [February 27, 2015]
+ Moved png_set_filter() prototype into a PNG_WRITE_SUPPORTED block
+ of png.h.
+ Avoid runtime checks when converting integer to png_byte with
+ Visual Studio (Sergey Kosarevsky)
+
+Version 1.6.17rc01 [March 4, 2015]
+ No changes.
+
+Version 1.6.17rc02 [March 9, 2015]
+ Removed some comments that the configure script did not handle
+ properly from scripts/pnglibconf.dfa and pnglibconf.h.prebuilt.
+ Free the unknown_chunks structure even when it contains no data.
+
+Version 1.6.17rc03 [March 12, 2015]
+ Updated CMakeLists.txt to add OSX framework, change YES/NO to ON/OFF
+ for consistency, and remove some useless tests (Alexey Petruchik).
+
+Version 1.6.17rc04 [March 16, 2015]
+ Remove pnglibconf.h, pnglibconf.c, and pnglibconf.out instead of
+ pnglibconf.* in "make clean" (Cosmin).
+ Fix bug in calculation of maxbits, in png_write_sBIT, introduced
+ in libpng-1.6.17beta01 (John Bowler).
+
+Version 1.6.17rc05 [March 21, 2015]
+ Define PNG_FILTER_* and PNG_FILTER_VALUE_* in png.h even when WRITE
+ is not supported (John Bowler). This fixes an error introduced in
+ libpng-1.6.17beta06.
+ Reverted "& 0xff" additions of version 1.6.17beta01. Libpng passes
+ the Coverity scan without them.
+
+Version 1.6.17rc06 [March 23, 2015]
+ Remove pnglibconf.dfn and pnglibconf.pre with "make clean".
+ Reformatted some "&0xff" instances to "& 0xff".
+ Fixed simplified 8-bit-linear to sRGB alpha. The calculated alpha
+ value was wrong. It's not clear if this affected the final stored
+ value; in the obvious code path the upper and lower 8-bits of the
+ alpha value were identical and the alpha was truncated to 8-bits
+ rather than dividing by 257 (John Bowler).
+
+Version 1.6.17 [March 26, 2015]
+ No changes.
+
+Version 1.6.18beta01 [April 1, 2015]
+ Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros. They
+ have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
+ bug report by Andrew Church).
+ Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c. This
+ fixes some arithmetic errors that caused some tests to fail on
+ some 32-bit platforms (Bug reports by Peter Breitenlohner [i686]
+ and Petr Gajdos [i586]).
+
+Version 1.6.18beta02 [April 26, 2015]
+ Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+ (Bug report by Viktor Szakats).
+
+Version 1.6.18beta03 [May 6, 2015]
+ Replaced "unexpected" with an integer (0xabadca11) in pngset.c
+ where a long was expected, to avoid a compiler warning when PNG_DEBUG > 1.
+ Added contrib/examples/simpleover.c, to demonstrate how to handle
+ alpha compositing of multiple images, using the "simplified API"
+ and an example PNG generation tool, contrib/examples/genpng.c
+ (John Bowler).
+
+Version 1.6.18beta04 [May 20, 2015]
+ PNG_RELEASE_BUILD replaces tests where the code depended on the build base
+ type and can be defined on the command line, allowing testing in beta
+ builds (John Bowler).
+ Avoid Coverity issue 80858 (REVERSE NULL) in pngtest.c PNG_DEBUG builds.
+ Avoid a harmless potential integer overflow in png_XYZ_from_xy() (Bug
+ report from Christopher Ferris).
+
+Version 1.6.18beta05 [May 31, 2015]
+ Backport filter selection code from libpng-1.7.0beta51, to combine
+ sub_row, up_row, avg_row, and paeth_row into try_row and tst_row.
+ Changed png_voidcast(), etc., to voidcast(), etc., in contrib/tools/pngfix.c
+ to avoid confusion with the libpng private macros.
+ Fixed old cut&paste bug in the weighted filter selection code in
+ pngwutil.c, introduced in libpng-0.95, March 1997.
+
+Version 1.6.18beta06 [June 1, 2015]
+ Removed WRITE_WEIGHTED_FILTERED code, to save a few kbytes of the
+ compiled library size. It never worked properly and as far as we can
+ tell, no one uses it. The png_set_filter_heuristics() and
+ png_set_filter_heuristics_fixed() APIs are retained but deprecated
+ and do nothing.
+
+Version 1.6.18beta07 [June 6, 2015]
+ Removed non-working progressive reader 'skip' function. This
+ function has apparently never been used. It was implemented
+ to support back-door modification of png_struct in libpng-1.4.x
+ but (because it does nothing and cannot do anything) was apparently
+ never tested (John Bowler).
+ Fixed cexcept.h in which GCC 5 now reports that one of the auto
+ variables in the Try macro needs to be volatile to prevent value
+ being lost over the setjmp (John Bowler).
+ Fixed NO_WRITE_FILTER and -Wconversion build breaks (John Bowler).
+ Fix g++ build breaks (John Bowler).
+ Quieted some Coverity issues in pngfix.c, png-fix-itxt.c, pngvalid.c,
+ pngstest.c, and pngimage.c. Most seem harmless, but png-fix-itxt
+ would only work with iTXt chunks with length 255 or less.
+ Added #ifdef's to contrib/examples programs so people don't try
+ to compile them without the minimum required support enabled
+ (suggested by Flavio Medeiros).
+
+Version 1.6.18beta08 [June 30, 2015]
+ Eliminated the final two Coverity defects (insecure temporary file
+ handling in contrib/libtests/pngstest.c; possible overflow of
+ unsigned char in contrib/tools/png-fix-itxt.c). To use the "secure"
+ file handling, define PNG_USE_MKSTEMP, otherwise "tmpfile()" will
+ be used.
+ Removed some unused WEIGHTED_FILTER macros from png.h and pngstruct.h
+
+Version 1.6.18beta09 [July 5, 2015]
+ Removed some useless typecasts from contrib/tools/png-fix-itxt.c
+ Fixed a new signed-unsigned comparison in pngrtran.c (Max Stepin).
+ Replaced arbitrary use of 'extern' with #define PNG_LINKAGE_*. To
+ preserve API compatibility, the new defines all default to "extern"
+ (requested by Jan Nijtmans).
+
+Version 1.6.18rc01 [July 9, 2015]
+ Belatedly added Mans Rullgard and James Yu to the list of Contributing
+ Authors.
+
+Version 1.6.18rc02 [July 12, 2015]
+ Restored unused FILTER_HEURISTIC macros removed at libpng-1.6.18beta08
+ to png.h to avoid compatibility warnings.
+
+Version 1.6.18rc03 [July 15, 2015]
+ Minor changes to the man page
+
+Version 1.6.18 [July 23, 2015]
+ No changes.
+
+Version 1.6.19beta01 [July 30, 2015]
+ Updated obsolete information about the simplified API macros in the
+ manual pages (Bug report by Arc Riley).
+ Avoid potentially dereferencing NULL info_ptr in png_info_init_3().
+ Rearranged png.h to put the major sections in the same order as
+ in libpng17.
+ Eliminated unused PNG_COST_SHIFT, PNG_WEIGHT_SHIFT, PNG_COST_FACTOR, and
+ PNG_WEIGHT_FACTOR macros.
+ Suppressed some warnings from the Borland C++ 5.5.1/5.82 compiler
+ (Bug report by Viktor Szakats). Several warnings remain and are
+ unavoidable, where we test for overflow.
+ Fixed potential leak of png_pixels in contrib/pngminus/pnm2png.c
+ Fixed uninitialized variable in contrib/gregbook/rpng2-x.c
+
+Version 1.6.19beta02 [August 19, 2015]
+ Moved config.h.in~ from the "libpng_autotools_files" list to the
+ "libpng_autotools_extra" list in autogen.sh because it was causing a
+ false positive for missing files (bug report by Robert C. Seacord).
+ Removed unreachable "break" statements in png.c, pngread.c, and pngrtran.c
+ to suppress clang warnings (Bug report by Viktor Szakats).
+ Fixed some bad links in the man page.
+ Changed "n bit" to "n-bit" in comments.
+ Added signed/unsigned 16-bit safety net. This removes the dubious
+ 0x8000 flag definitions on 16-bit systems. They aren't supported
+ yet the defs *probably* work, however it seems much safer to do this
+ and be advised if anyone, contrary to advice, is building libpng 1.6
+ on a 16-bit system. It also adds back various switch default clauses
+ for GCC; GCC errors out if they are not present (with an appropriately
+ high level of warnings).
+ Safely convert num_bytes to a png_byte in png_set_sig_bytes() (Robert
+ Seacord).
+ Fixed the recently reported 1's complement security issue by replacing
+ the value that is illegal in the PNG spec, in both signed and unsigned
+ values, with 0. Illegal unsigned values (anything greater than or equal
+ to 0x80000000) can still pass through, but since these are not illegal
+ in ANSI-C (unlike 0x80000000 in the signed case) the checking that
+ occurs later can catch them (John Bowler).
+
+Version 1.6.19beta03 [September 26, 2015]
+ Fixed png_save_int_32 when int is not 2's complement (John Bowler).
+ Updated libpng16 with all the recent test changes from libpng17,
+ including changes to pngvalid.c to ensure that the original,
+ distributed, version of contrib/visupng/cexcept.h can be used
+ (John Bowler).
+ pngvalid contains the correction to the use of SAVE/STORE_
+ UNKNOWN_CHUNKS; a bug revealed by changes in libpng 1.7. More
+ tests contain the --strict option to detect warnings and the
+ pngvalid-standard test has been corrected so that it does not
+ turn on progressive-read. There is a separate test which does
+ that. (John Bowler)
+ Also made some signed/unsigned fixes.
+ Make pngstest error limits version specific. Splitting the machine
+ generated error structs out to a file allows the values to be updated
+ without changing pngstest.c itself. Since libpng 1.6 and 1.7 have
+ slightly different error limits this simplifies maintenance. The
+ makepngs.sh script has also been updated to more accurately reflect
+ current problems in libpng 1.7 (John Bowler).
+ Incorporated new test PNG files into make check. tests/pngstest-*
+ are changed so that the new test files are divided into 8 groups by
+ gamma and alpha channel. These tests have considerably better code
+ and pixel-value coverage than contrib/pngsuite; however,coverage is
+ still incomplete (John Bowler).
+ Removed the '--strict' in 1.6 because of the double-gamma-correction
+ warning, updated pngstest-errors.h for the errors detected with the
+ new contrib/testspngs PNG test files (John Bowler).
+
+Version 1.6.19beta04 [October 15, 2015]
+ Worked around rgb-to-gray issues in libpng 1.6. The previous
+ attempts to ignore the errors in the code aren't quite enough to
+ deal with the 'channel selection' encoding added to libpng 1.7; abort.
+ pngvalid.c is changed to drop this encoding in prior versions.
+ Fixed 'pow' macros in pngvalid.c. It is legal for 'pow' to be a
+ macro, therefore the argument list cannot contain preprocessing
+ directives. Make sure pow is a function where this happens. This is
+ a minimal safe fix, the issue only arises in non-performance-critical
+ code (bug report by Curtis Leach, fix by John Bowler).
+ Added sPLT support to pngtest.c
+
+Version 1.6.19rc01 [October 23, 2015]
+ No changes.
+
+Version 1.6.19rc02 [October 31, 2015]
+ Prevent setting or writing over-length PLTE chunk (Cosmin Truta).
+ Silently truncate over-length PLTE chunk while reading.
+ Libpng incorrectly calculated the output rowbytes when the application
+ decreased either the number of channels or the bit depth (or both) in
+ a user transform. This was safe; libpng overallocated buffer space
+ (potentially by quite a lot; up to 4 times the amount required) but,
+ from 1.5.4 on, resulted in a png_error (John Bowler).
+
+Version 1.6.19rc03 [November 3, 2015]
+ Fixed some inconsequential cut-and-paste typos in png_set_cHRM_XYZ_fixed().
+ Clarified COPYRIGHT information to state explicitly that versions
+ are derived from previous versions.
+ Removed much of the long list of previous versions from png.h and
+ libpng.3.
+
+Version 1.6.19rc04 [November 5, 2015]
+ Fixed new bug with CRC error after reading an over-length palette
+ (bug report by Cosmin Truta) (CVE-2015-8126).
+
+Version 1.6.19 [November 12, 2015]
+ Cleaned up coding style in png_handle_PLTE().
+
+Version 1.6.20beta01 [November 20, 2015]
+ Avoid potential pointer overflow/underflow in png_handle_sPLT() and
+ png_handle_pCAL() (Bug report by John Regehr).
+
+Version 1.6.20beta02 [November 23, 2015]
+ Fixed incorrect implementation of png_set_PLTE() that uses png_ptr
+ not info_ptr, that left png_set_PLTE() open to the CVE-2015-8126
+ vulnerability. Fixes CVE-2015-8472.
+
+Version 1.6.20beta03 [November 24, 2015]
+ Backported tests from libpng-1.7.0beta69.
+
+Version 1.6.20rc01 [November 26, 2015]
+ Fixed an error in handling of bad zlib CMINFO field in pngfix, found by
+ American Fuzzy Lop, reported by Brian Carpenter. inflate() doesn't
+ immediately fault a bad CMINFO field; instead a 'too far back' error
+ happens later (at least some times). pngfix failed to limit CMINFO to
+ the allowed values but then assumed that window_bits was in range,
+ triggering an assert. The bug is mostly harmless; the PNG file cannot
+ be fixed.
+
+Version 1.6.20rc02 [November 29, 2015]
+ In libpng 1.6 zlib initialization was changed to use the window size
+ in the zlib stream, not a fixed value. This causes some invalid images,
+ where CINFO is too large, to display 'correctly' if the rest of the
+ data is valid. This provides a workaround for zlib versions where the
+ error arises (ones that support the API change to use the window size
+ in the stream).
+
+Version 1.6.20 [December 3, 2015]
+ No changes.
+
+Version 1.6.21beta01 [December 11, 2015]
+ Fixed syntax "$(command)" in tests/pngstest that some shells other than
+ bash could not parse (Bug report by Nelson Beebe). Use `command` instead.
+
+Version 1.6.21beta02 [December 14, 2015]
+ Moved png_check_keyword() from pngwutil.c to pngset.c
+ Removed LE/BE dependencies in pngvalid, to 'fix' the current problem
+ in the BigEndian tests by not testing it, making the BE code the same
+ as the LE version.
+ Fixes to pngvalid for various reduced build configurations (eliminate unused
+ statics) and a fix for the case in rgb_to_gray when the digitize option
+ reduces graylo to 0, producing a large error.
+
+Version 1.6.21beta03 [December 18, 2015]
+ Widened the 'limit' check on the internally calculated error limits in
+ the 'DIGITIZE' case (the code used prior to 1.7 for rgb_to_gray error
+ checks) and changed the check to only operate in non-release builds
+ (base build type not RC or RELEASE.)
+ Fixed undefined behavior in pngvalid.c, undefined because
+ (png_byte) << shift is undefined if it changes the signed bit
+ (because png_byte is promoted to int). The libpng exported functions
+ png_get_uint_32 and png_get_uint_16 handle this. (Bug reported by
+ David Drysdale as a result of reports from UBSAN in clang 3.8).
+ This changes pngvalid to use BE random numbers; this used to produce
+ errors but these should not be fixed as a result of the previous changes.
+
+Version 1.6.21rc01 [January 4, 2016]
+ In projects/vstudio, combined readme.txt and WARNING into README.txt
+
+Version 1.6.21rc02 [January 7, 2016]
+ Relocated assert() in contrib/tools/pngfix.c, bug found by American
+ Fuzzy Lop, reported by Brian Carpenter.
+ Marked 'limit' UNUSED in transform_range_check(). This only affects
+ release builds.
+
+Version 1.6.21 [January 15, 2016]
+ Worked around a false-positive Coverity issue in pngvalid.c.
+
+Version 1.6.22beta01 [January 23, 2016]
+ Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
+ "tmpfile()" implementation in contrib/libtests/pngstest.c
+ Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
+ if there is no stdio.h support.
+ Added a png_image_write_to_memory() API and a number of assist macros
+ to allow an application that uses the simplified API write to bypass
+ stdio and write directly to memory.
+ Added some warnings (png.h) and some check code to detect *possible*
+ overflow in the ROW_STRIDE and simplified image SIZE macros. This
+ disallows image width/height/format that *might* overflow. This is
+ a quiet API change that limits in-memory image size (uncompressed) to
+ less than 4GByte and image row size (stride) to less than 2GByte.
+ Revised workaround for false-positive Coverity issue in pngvalid.c.
+
+Version 1.6.22beta02 [February 8, 2016]
+ Only use exit(77) in configure builds.
+ Corrected error in PNG_IMAGE_PNG_SIZE_MAX. This new macro underreported
+ the palette size because it failed to take into account that the memory
+ palette has to be expanded to full RGB when it is written to PNG.
+ Updated CMakeLists.txt, added supporting scripts/gen*.cmake.in
+ and test.cmake.in (Roger Leigh).
+ Relaxed limit checks on gamma values in pngrtran.c. As suggested in
+ the comments gamma values outside the range currently permitted
+ by png_set_alpha_mode are useful for HDR data encoding. These values
+ are already permitted by png_set_gamma so it is reasonable caution to
+ extend the png_set_alpha_mode range as HDR imaging systems are starting
+ to emerge.
+
+Version 1.6.22beta03 [March 9, 2016]
+ Added a common-law trademark notice and export control information
+ to the LICENSE file, png.h, and the man page.
+ Restored "& 0xff" in png_save_uint_16() and png_save_uint_32() that
+ were accidentally removed from libpng-1.6.17.
+ Changed PNG_INFO_cHNK and PNG_FREE_cHNK from 0xnnnn to 0xnnnnU in png.h
+ (Robert C. Seacord).
+ Removed dubious "#if INT_MAX" test from png.h that was added to
+ libpng-1.6.19beta02 (John Bowler).
+ Add ${INCLUDES} in scripts/genout.cmake.in (Bug report by Nixon Kwok).
+ Updated LICENSE to say files in the contrib directory are not
+ necessarily under the libpng license, and that some makefiles have
+ other copyright owners.
+ Added INTEL-SSE2 support (Mike Klein and Matt Sarett, Google, Inc.).
+ Made contrib/libtests/timepng more robust. The code no longer gives
+ up/fails on invalid PNG data, it just skips it (with error messages).
+ The code no longer fails on PNG files with data beyond IEND. Options
+ exist to use png_read_png (reading the whole image, not by row) and, in
+ that case, to apply any of the supported transforms. This makes for
+ more realistic testing; the decoded data actually gets used in a
+ meaningful fashion (John Bowler).
+ Fixed some misleading indentation (Krishnaraj Bhat).
+
+Version 1.6.22beta04 [April 5, 2016]
+ Force GCC compilation to C89 if needed (Dagobert Michelsen).
+ SSE filter speed improvements for bpp=3:
+ memcpy-free implementations of load3() / store3().
+ call load3() only when needed at the end of a scanline.
+
+Version 1.6.22beta05 [April 27, 2016]
+ Added PNG_FAST_FILTERS macro (defined as
+ PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP).
+ Various fixes for contrib/libtests/timepng.c
+ Moved INTEL-SSE code from pngpriv.h into contrib/intel/intel_sse.patch.
+ Fixed typo (missing underscore) in #define PNG_READ_16_TO_8_SUPPORTED
+ (Bug report by Y.Ohashik).
+
+Version 1.6.22beta06 [May 5, 2016]
+ Rebased contrib/intel_sse.patch.
+ Quieted two Coverity issues in contrib/libtests/timepng.c.
+ Fixed issues with scripts/genout.cmake.in (David Capello, Nixon Kwok):
+ Added support to use multiple directories in ZLIBINCDIR variable,
+ Fixed CMAKE_C_FLAGS with multiple values when genout is compiled on MSVC,
+ Fixed pnglibconf.c compilation on OS X including the sysroot path.
+
+Version 1.6.22rc01 [May 14, 2016]
+ No changes.
+
+Version 1.6.22rc02 [May 16, 2016]
+ Removed contrib/timepng from default build; it does not build on platforms
+ that don't supply clock_gettime().
+
+Version 1.6.22rc03 [May 17, 2016]
+ Restored contrib/timepng to default build but check for the presence
+ of clock_gettime() in configure.ac and Makefile.am.
+
+Version 1.6.22 [May 26, 2016]
+ No changes.
+
+Version 1.6.23beta01 [May 29, 2016]
+ Stop a potential memory leak in png_set_tRNS() (Bug report by Ted Ying).
+ Fixed the progressive reader to handle empty first IDAT chunk properly
+ (patch by Timothy Nikkel). This bug was introduced in libpng-1.6.0 and
+ only affected the libpng16 branch.
+ Added tests in pngvalid.c to check zero-length IDAT chunks in various
+ positions. Fixed the sequential reader to handle these more robustly
+ (John Bowler).
+
+Version 1.6.23rc01 [June 2, 2016]
+ Corrected progressive read input buffer in pngvalid.c. The previous version
+ the code invariably passed just one byte at a time to libpng. The intent
+ was to pass a random number of bytes in the range 0..511.
+ Moved sse2 prototype from pngpriv.h to contrib/intel/intel_sse.patch.
+ Added missing ")" in pngerror.c (Matt Sarrett).
+
+Version 1.6.23rc02 [June 4, 2016]
+ Fixed undefined behavior in png_push_save_buffer(). Do not call
+ memcpy() with a null source, even if count is zero (Leon Scroggins III).
+
+Version 1.6.23 [June 9, 2016]
+ Fixed bad link to RFC2083 in png.5 (Nikola Forro).
+
+Version 1.6.24beta01 [June 11, 2016]
+ Avoid potential overflow of the PNG_IMAGE_SIZE macro. This macro
+ is not used within libpng, but is used in some of the examples.
+
+Version 1.6.24beta02 [June 23, 2016]
+ Correct filter heuristic overflow handling. This was broken when the
+ write filter code was moved out-of-line; if there is a single filter and
+ the heuristic sum overflows the calculation of the filtered line is not
+ completed. In versions prior to 1.6 the code was duplicated in-line
+ and the check not performed, so the filter operation completed; however,
+ in the multi-filter case where the sum is performed the 'none' filter would
+ be selected if all the sums overflowed, even if it wasn't in the filter
+ list. The fix to the first problem is simply to provide PNG_SIZE_MAX as
+ the current lmins sum value; this means the sum can never exceed it and
+ overflows silently. A reasonable compiler that does choose to inline
+ the code will simply eliminate the sum check.
+ The fix to the second problem is to use high precision arithmetic (this is
+ implemented in 1.7), however a simple safe fix here is to chose the lowest
+ numbered filter in the list from png_set_filter (this only works if the
+ first problem is also fixed) (John Bowler).
+ Use a more efficient absolute value calculation on SSE2 (Matthieu Darbois).
+ Fixed the case where PNG_IMAGE_BUFFER_SIZE can overflow in the application
+ as a result of the application using an increased 'row_stride'; previously
+ png_image_finish_read only checked for overflow on the base calculation of
+ components. (I.e. it checked for overflow of a 32-bit number on the total
+ number of pixel components in the output format, not the possibly padded row
+ length and not the number of bytes, which for linear formats is twice the
+ number of components.)
+ MSVC does not like '-(unsigned)', so replaced it with 0U-(unsigned)
+ MSVC does not like (uInt) = -(unsigned) (i.e. as an initializer), unless
+ the conversion is explicitly invoked by a cast.
+ Put the SKIP definition in the correct place. It needs to come after the
+ png.h include (see all the other .c files in contrib/libtests) because it
+ depends on PNG_LIBPNG_VER.
+ Removed the three compile warning options from the individual project
+ files into the zlib.props globals. It increases the warning level from 4
+ to All and adds a list of the warnings that need to be turned off. This is
+ semi-documentary; the intent is to tell libpng users which warnings have
+ been examined and judged non-fixable at present. The warning about
+ structure padding is fixable, but it would be a significant change (moving
+ structure members around).
+
+Version 1.6.24beta03 [July 4, 2016]
+ Optimized absolute value calculation in filter selection, similar to
+ code in the PAETH decoder in pngrutil.c. Build with PNG_USE_ABS to
+ use this.
+ Added pngcp to the build together with a pngcp.dfa configuration test.
+ Added high resolution timing to pngcp.
+ Added "Common linking failures" section to INSTALL.
+ Relocated misplaced #endif in png.c sRGB profile checking.
+ Fixed two Coverity issues in pngcp.c.
+
+Version 1.6.24beta04 [July 8, 2016]
+ Avoid filter-selection heuristic sum calculations in cases where only one
+ filter is a candidate for selection. This trades off code size (added
+ private png_setup_*_row_only() functions) for speed.
+
+Version 1.6.24beta05 [July 13, 2016]
+ Fixed some indentation to comply with our coding style.
+ Added contrib/tools/reindent.
+
+Version 1.6.24beta06 [July 18, 2016]
+ Fixed more indentation to comply with our coding style.
+ Eliminated unnecessary tests of boolean png_isaligned() vs 0.
+
+Version 1.6.24rc01 [July 25, 2016]
+ No changes.
+
+Version 1.6.24rc02 [August 1, 2016]
+ Conditionally compile SSE2 headers in contrib/intel/intel_sse.patch
+ Conditionally compile png_decompress_chunk().
+
+Version 1.6.24rc03 [August 2, 2016]
+ Conditionally compile ARM_NEON headers in pngpriv.h
+ Updated contrib/intel/intel_sse.patch
+
+Version 1.6.24[August 4, 2016]
+ No changes.
+
+Version 1.6.25beta01 [August 12, 2016]
+ Reject oversized iCCP profile immediately.
+ Cleaned up PNG_DEBUG compile of pngtest.c.
+ Conditionally compile png_inflate().
+
+Version 1.6.25beta02 [August 18, 2016]
+ Don't install pngcp; it conflicts with pngcp in the pngtools package.
+ Minor editing of INSTALL, (whitespace, added copyright line)
+
+Version 1.6.25rc01 [August 24, 2016]
+ No changes.
+
+Version 1.6.25rc02 [August 29, 2016]
+ Added MIPS support (Mandar Sahastrabuddhe <Mandar.Sahastrabuddhe@imgtec.com>).
+ Only the UP filter is currently implemented.
+
+Version 1.6.25rc03 [August 29, 2016]
+ Rebased contrib/intel/intel_sse.patch after the MIPS implementation.
+
+Version 1.6.25rc04 [August 30, 2016]
+ Added MIPS support for SUB, AVG, and PAETH filters (Mandar Sahastrabuddhe).
+
+Version 1.6.25rc05 [August 30, 2016]
+ Rebased contrib/intel/intel_sse.patch after the MIPS implementation update..
+
+Version 1.6.25 [September 1, 2016]
+ No changes.
+
+Version 1.6.26beta01 [September 26, 2016]
+ Fixed handling zero length IDAT in pngfix (bug report by Agostino Sarubbo,
+ bugfix by John Bowler).
+ Do not issue a png_error() on read in png_set_pCAL() because png_handle_pCAL
+ has allocated memory that libpng needs to free.
+ Conditionally compile png_set_benign_errors() in pngread.c and pngtest.c
+ Issue a png_benign_error instead of a png_error on ADLER32 mismatch
+ while decoding compressed data chunks.
+ Changed PNG_ZLIB_VERNUM to ZLIB_VERNUM in pngpriv.h, pngstruct.h, and
+ pngrutil.c.
+ If CRC handling of critical chunks has been set to PNG_CRC_QUIET_USE,
+ ignore the ADLER32 checksum in the IDAT chunk as well as the chunk CRCs.
+ Issue png_benign_error() on ADLER32 checksum mismatch instead of png_error().
+ Add tests/badcrc.png and tests/badadler.png to tests/pngtest.
+ Merged pngtest.c with libpng-1.7.0beta84/pngtest.c
+
+Version 1.6.26beta02 [October 1, 2016]
+ Updated the documentation about CRC and ADLER32 handling.
+ Quieted 117 warnings from clang-3.8 in pngtrans.c, pngread.c,
+ pngwrite.c, pngunknown.c, and pngvalid.c.
+ Quieted 58 (out of 144) -Wconversion compiler warnings by changing
+ flag definitions in pngpriv.h from 0xnnnn to 0xnnnnU and trivial changes
+ in png.c, pngread.c, and pngwutil.c.
+
+Version 1.6.26beta03 [October 2, 2016]
+ Removed contrib/libtests/*.orig and *.rej that slipped into the tarballs.
+ Quieted the 86 remaining -Wconversion compiler warnings by
+ revising the png_isaligned() macro and trivial changes in png.c,
+ pngerror.c, pngget.c, pngmem.c, pngset.c, pngrtran.c, pngrutil.c,
+ pngwtran.c, pngwrite.c, and pngwutil.c.
+
+Version 1.6.26beta04 [October 3, 2016]
+ Quieted (bogus?) clang warnings about "absolute value has no effect"
+ when PNG_USE_ABS is defined.
+ Fixed offsets in contrib/intel/intel_sse.patch
+
+Version 1.6.26beta05 [October 6, 2016]
+ Changed integer constant 4294967294 to unsigned 4294967294U in pngconf.h
+ to avoid a signed/unsigned compare in the preprocessor.
+
+Version 1.6.26beta06 [October 7, 2016]
+ Use zlib-1.2.8.1 inflateValidate() instead of inflateReset2() to
+ optionally avoid ADLER32 evaluation.
+
+Version 1.6.26rc01 [October 12, 2016]
+ No changes.
+
+Version 1.6.26 [October 20, 2016]
+ Cosmetic change, "ptr != 0" to "ptr != NULL" in png.c and pngrutil.c
+ Despammed email addresses (replaced "@" with " at ").
+
+Version 1.6.27beta01 [November 2, 2016]
+ Restrict the new ADLER32-skipping to IDAT chunks. It broke iCCP chunk
+ handling: an erroneous iCCP chunk would throw a png_error and reject the
+ entire PNG image instead of rejecting just the iCCP chunk with a warning,
+ if built with zlib-1.2.8.1.
+
+Version 1.6.27rc01 [December 27, 2016]
+ Control ADLER32 checking with new PNG_IGNORE_ADLER32 option. Fixes
+ an endless loop when handling erroneous ADLER32 checksums; bug
+ introduced in libpng-1.6.26.
+ Removed the use of a macro containing the pre-processor 'defined'
+ operator. It is unclear whether this is valid; a macro that
+ "generates" 'defined' is not permitted, but the use of the word
+ "generates" within the C90 standard seems to imply more than simple
+ substitution of an expression itself containing a well-formed defined
+ operation.
+ Added ARM support to CMakeLists.txt (Andreas Franek).
+
+Version 1.6.27 [December 29, 2016]
+ Fixed a potential null pointer dereference in png_set_text_2() (bug report
+ and patch by Patrick Keshishian, CVE-2016-10087).
+
+Version 1.6.28rc01 [January 3, 2017]
+ Fixed arm/aarch64 detection in CMakeLists.txt (Gianfranco Costamagna).
+ Added option to Cmake build allowing a custom location of zlib to be
+ specified in a scenario where libpng is being built as a subproject
+ alongside zlib by another project (Sam Serrels).
+ Changed png_ptr->options from a png_byte to png_uint_32, to accommodate
+ up to 16 options.
+
+Version 1.6.28rc02 [January 4, 2017]
+ Added "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+ Moved SSE2 optimization code into the main libpng source directory.
+ Configure libpng with "configure --enable-intel-sse" or compile
+ libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+
+Version 1.6.28rc03 [January 4, 2017]
+ Backed out the SSE optimization and last CMakeLists.txt to allow time for QA.
+
+Version 1.6.28 [January 5, 2017]
+ No changes.
+
+Version 1.6.29beta01 [January 12, 2017]
+ Readded "include(GNUInstallDirs)" to CMakeLists.txt (Gianfranco Costamagna).
+ Moved SSE2 optimization code into the main libpng source directory.
+ Configure libpng with "configure --enable-intel-sse" or compile
+ libpng with "-DPNG_INTEL_SSE" in CPPFLAGS to enable it.
+ Simplified conditional compilation in pngvalid.c, for AIX (Michael Felt).
+
+Version 1.6.29beta02 [February 22, 2017]
+ Avoid conditional directives that break statements in pngrutil.c (Romero
+ Malaquias)
+ The contrib/examples/pngtopng.c recovery code was in the wrong "if"
+ branches; the comments were correct.
+ Added code for PowerPC VSX optimisation (Vadim Barkov).
+
+Version 1.6.29beta03 [March 1, 2017]
+ Avoid potential overflow of shift operations in png_do_expand() (Aaron Boxer).
+ Change test ZLIB_VERNUM >= 0x1281 to ZLIB_VERNUM >= 0x1290 in pngrutil.c
+ because Solaris 11 distributes zlib-1.2.8.f that is older than 1.2.8.1,
+ as suggested in zlib FAQ, item 24.
+ Suppress clang warnings about implicit sign changes in png.c
+
+Version 1.6.29 [March 16, 2017]
+ No changes.
+
+Version 1.6.30beta01 [April 1, 2017]
+ Added missing "$(CPPFLAGS)" to the compile line for c.pic.o in
+ makefile.linux and makefile.solaris-x86 (Cosmin).
+ Revised documentation of png_get_error_ptr() in the libpng manual.
+ Silence clang -Wcomma and const drop warnings (Viktor Szakats).
+ Update Sourceforge URLs in documentation (https instead of http).
+
+Version 1.6.30beta02 [April 22, 2017]
+ Document need to check for integer overflow when allocating a pixel
+ buffer for multiple rows in contrib/gregbook, contrib/pngminus,
+ example.c, and in the manual (suggested by Jaeseung Choi). This
+ is similar to the bug reported against pngquant in CVE-2016-5735.
+ Removed reference to the obsolete PNG_SAFE_LIMITS macro in the documentation.
+
+Version 1.6.30beta03 [May 22, 2017]
+ Check for integer overflow in contrib/visupng and contrib/tools/genpng.
+ Do not double evaluate CMAKE_SYSTEM_PROCESSOR in CMakeLists.txt.
+ Test CMAKE_HOST_WIN32 instead of WIN32 in CMakeLists.txt.
+ Fix some URL in documentation.
+
+Version 1.6.30beta04 [June 7, 2017]
+ Avoid writing an empty IDAT when the last IDAT exactly fills the
+ compression buffer (bug report by Brian Baird). This bug was
+ introduced in libpng-1.6.0.
+
+Version 1.6.30rc01 [June 14, 2017]
+ No changes.
+
+Version 1.6.30rc02 [June 25, 2017]
+ Update copyright year in pnglibconf.h, make ltmain.sh executable.
+ Add a reference to the libpng.download site in README.
+
+Version 1.6.30 [June 28, 2017]
+ No changes.
+
+Version 1.6.31beta01 [July 5, 2017]
+ Guard the definition of _POSIX_SOURCE in pngpriv.h (AIX already defines it;
+ bug report by Michael Felt).
+ Revised pngpriv.h to work around failure to compile arm/filter_neon.S
+ ("typedef" directive is unrecognized by the assembler). The problem
+ was introduced in libpng-1.6.30beta01.
+ Added "Requires: zlib" to libpng.pc.in (Pieter Neerincx).
+ Added special case for FreeBSD in arm/filter_neon.S (Maya Rashish).
+
+Version 1.6.31beta02 [July 8, 2017]
+ Added instructions for disabling hardware optimizations in INSTALL.
+ Added "--enable-hardware-optimizations" configuration flag to enable
+ or disable all hardware optimizations with one flag.
+
+Version 1.6.31beta03 [July 9, 2017]
+ Updated CMakeLists.txt to add INTEL_SSE and MIPS_MSA platforms.
+ Changed "int" to "png_size_t" in intel/filter_sse2.c to prevent
+ possible integer overflow (Bug report by John Bowler).
+ Quieted "declaration after statement" warnings in intel/filter_sse2.c.
+ Added scripts/makefile-linux-opt, which has hardware optimizations enabled.
+
+Version 1.6.31beta04 [July 11, 2017]
+ Removed one of the GCC-7.1.0 'strict-overflow' warnings that result when
+ integers appear on both sides of a compare. Worked around the others by
+ forcing the strict-overflow setting in the relevant functions to a level
+ where they are not reported (John Bowler).
+ Changed "FALL THROUGH" comments to "FALLTHROUGH" because GCC doesn't like
+ the space.
+ Worked around some C-style casts from (void*) because g++ 5.4.0 objects
+ to them.
+ Increased the buffer size for 'sprint' to pass the gcc 7.1.0 'sprint
+ overflow' check that is on by default with -Wall -Wextra.
+
+Version 1.6.31beta05 [July 13, 2017]
+ Added eXIf chunk support.
+
+Version 1.6.31beta06 [July 17, 2017]
+ Added a minimal eXIf chunk (with Orientation and FocalLengthIn35mmFilm
+ tags) to pngtest.png.
+
+Version 1.6.31beta07 [July 18, 2017]
+ Revised the eXIf chunk in pngtest.png to fix "Bad IFD1 Directory" warning.
+
+Version 1.6.31rc01 [July 19, 2017]
+ No changes.
+
+Version 1.6.31rc02 [July 25, 2017]
+ Fixed typo in example.c (png_free_image should be png_image_free) (Bug
+ report by John Smith)
+
+Version 1.6.31 [July 27, 2017]
+ No changes.
+
+Version 1.6.32beta01 [July 31, 2017]
+ Avoid possible NULL dereference in png_handle_eXIf when benign_errors
+ are allowed. Avoid leaking the input buffer "eXIf_buf".
+ Eliminated png_ptr->num_exif member from pngstruct.h and added num_exif
+ to arguments for png_get_eXIf() and png_set_eXIf().
+ Added calls to png_handle_eXIf(() in pngread.c and png_write_eXIf() in
+ pngwrite.c, and made various other fixes to png_write_eXIf().
+ Changed name of png_get_eXIF and png_set_eXIf() to png_get_eXIf_1() and
+ png_set_eXIf_1(), respectively, to avoid breaking API compatibility
+ with libpng-1.6.31.
+
+Version 1.6.32beta02 [August 1, 2017]
+ Updated contrib/libtests/pngunknown.c with eXIf chunk.
+
+Version 1.6.32beta03 [August 2, 2017]
+ Initialized btoa[] in pngstest.c
+ Stop memory leak when returning from png_handle_eXIf() with an error
+ (Bug report from the OSS-fuzz project).
+
+Version 1.6.32beta04 [August 2, 2017]
+ Replaced local eXIf_buf with info_ptr-eXIf_buf in png_handle_eXIf().
+ Update libpng.3 and libpng-manual.txt about eXIf functions.
+
+Version 1.6.32beta05 [August 2, 2017]
+ Restored png_get_eXIf() and png_set_eXIf() to maintain API compatibility.
+
+Version 1.6.32beta06 [August 2, 2017]
+ Removed png_get_eXIf_1() and png_set_eXIf_1().
+
+Version 1.6.32beta07 [August 3, 2017]
+ Check length of all chunks except IDAT against user limit to fix an
+ OSS-fuzz issue (Fixes CVE-2017-12652).
+
+Version 1.6.32beta08 [August 3, 2017]
+ Check length of IDAT against maximum possible IDAT size, accounting
+ for height, rowbytes, interlacing and zlib/deflate overhead.
+ Restored png_get_eXIf_1() and png_set_eXIf_1(), because strlen(eXIf_buf)
+ does not work (the eXIf chunk data can contain zeroes).
+
+Version 1.6.32beta09 [August 3, 2017]
+ Require cmake-2.8.8 in CMakeLists.txt. Revised symlink creation,
+ no longer using deprecated cmake LOCATION feature (Clifford Yapp).
+ Fixed five-byte error in the calculation of IDAT maximum possible size.
+
+Version 1.6.32beta10 [August 5, 2017]
+ Moved chunk-length check into a png_check_chunk_length() private
+ function (Suggested by Max Stepin).
+ Moved bad pngs from tests to contrib/libtests/crashers
+ Moved testing of bad pngs into a separate tests/pngtest-badpngs script
+ Added the --xfail (expected FAIL) option to pngtest.c. It writes XFAIL
+ in the output but PASS for the libpng test.
+ Require cmake-3.0.2 in CMakeLists.txt (Clifford Yapp).
+ Fix "const" declaration info_ptr argument to png_get_eXIf_1() and the
+ num_exif argument to png_get_eXIf_1() (Github Issue 171).
+
+Version 1.6.32beta11 [August 7, 2017]
+ Added "eXIf" to "chunks_to_ignore[]" in png_set_keep_unknown_chunks().
+ Added huge_IDAT.png and empty_ancillary_chunks.png to testpngs/crashers.
+ Make pngtest --strict, --relax, --xfail options imply -m (multiple).
+ Removed unused chunk_name parameter from png_check_chunk_length().
+ Relocated setting free_me for eXIf data, to stop an OSS-fuzz leak.
+ Initialize profile_header[] in png_handle_iCCP() to fix OSS-fuzz issue.
+ Initialize png_ptr->row_buf[0] to 255 in png_read_row() to fix OSS-fuzz UMR.
+ Attempt to fix a UMR in png_set_text_2() to fix OSS-fuzz issue.
+ Increase minimum zlib stream from 9 to 14 in png_handle_iCCP(), to account
+ for the minimum 'deflate' stream, and relocate the test to a point
+ after the keyword has been read.
+ Check that the eXIf chunk has at least 2 bytes and begins with "II" or "MM".
+
+Version 1.6.32rc01 [August 18, 2017]
+ Added a set of "huge_xxxx_chunk.png" files to contrib/testpngs/crashers,
+ one for each known chunk type, with length = 2GB-1.
+ Check for 0 return from png_get_rowbytes() and added some (size_t) typecasts
+ in contrib/pngminus/*.c to stop some Coverity issues (162705, 162706,
+ and 162707).
+ Renamed chunks in contrib/testpngs/crashers to avoid having files whose
+ names differ only in case; this causes problems with some platforms
+ (github issue #172).
+
+Version 1.6.32rc02 [August 22, 2017]
+ Added contrib/oss-fuzz directory which contains files used by the oss-fuzz
+ project (https://github.com/google/oss-fuzz/tree/master/projects/libpng).
+
+Version 1.6.32 [August 24, 2017]
+ No changes.
+
+Version 1.6.33beta01 [August 28, 2017]
+ Added PNGMINUS_UNUSED macro to contrib/pngminus/p*.c and added missing
+ parenthesis in contrib/pngminus/pnm2png.c (bug report by Christian Hesse).
+ Fixed off-by-one error in png_do_check_palette_indexes() (Bug report
+ by Mick P., Source Forge Issue #269).
+
+Version 1.6.33beta02 [September 3, 2017]
+ Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+ to fix shortlived oss-fuzz issue 3234.
+ Compute a larger limit on IDAT because some applications write a deflate
+ buffer for each row (Bug report by Andrew Church).
+ Use current date (DATE) instead of release-date (RDATE) in last
+ changed date of contrib/oss-fuzz files.
+ Enabled ARM support in CMakeLists.txt (Bernd Kuhls).
+
+Version 1.6.33beta03 [September 14, 2017]
+ Fixed incorrect typecast of some arguments to png_malloc() and
+ png_calloc() that were png_uint_32 instead of png_alloc_size_t
+ (Bug report by "irwir" in Github libpng issue #175).
+ Use pnglibconf.h.prebuilt when building for ANDROID with cmake (Github
+ issue 162, by rcdailey).
+
+Version 1.6.33rc01 [September 20, 2017]
+ Initialize memory allocated by png_inflate to zero, using memset, to
+ stop an oss-fuzz "use of uninitialized value" detection in png_set_text_2()
+ due to truncated iTXt or zTXt chunk.
+ Initialize memory allocated by png_read_buffer to zero, using memset, to
+ stop an oss-fuzz "use of uninitialized value" detection in
+ png_icc_check_tag_table() due to truncated iCCP chunk.
+ Removed a redundant test (suggested by "irwir" in Github issue #180).
+
+Version 1.6.33rc02 [September 23, 2017]
+ Added an interlaced version of each file in contrib/pngsuite.
+ Relocate new memset() call in pngrutil.c.
+ Removed more redundant tests (suggested by "irwir" in Github issue #180).
+ Add support for loading images with associated alpha in the Simplified
+ API (Samuel Williams).
+
+Version 1.6.33 [September 28, 2017]
+ Revert contrib/oss-fuzz/libpng_read_fuzzer.cc to libpng-1.6.32 state.
+ Initialize png_handler.row_ptr in contrib/oss-fuzz/libpng_read_fuzzer.cc
+ Add end_info structure and png_read_end() to the libpng fuzzer.
+
+Version 1.6.34 [September 29, 2017]
+ Removed contrib/pngsuite/i*.png; some of them caused test failures.
+
+Version 1.6.35beta01 [March 6, 2018]
+ Restored 21 of the contrib/pngsuite/i*.png, which do not cause test
+ failures. Placed the remainder in contrib/pngsuite/interlaced/i*.png.
+ Added calls to png_set_*() transforms commonly used by browsers to
+ the fuzzer.
+ Removed some unnecessary brackets in pngrtran.c
+ Fixed miscellaneous typos (Patch by github user "luzpaz").
+ Change "ASM C" to "C ASM" in CMakeLists.txt
+ Fixed incorrect handling of bKGD chunk in sub-8-bit files (Cosmin)
+ Added hardware optimization directories to zip and 7z distributions.
+ Fixed incorrect bitmask for options.
+ Fixed many spelling typos.
+
+Version 1.6.35beta02 [March 28, 2018]
+ Make png_get_iCCP consistent with man page (allow compression-type argument
+ to be NULL, bug report by Lenard Szolnoki).
+
+Version 1.6.35 [July 15, 2018]
+ Replaced the remaining uses of png_size_t with size_t (Cosmin)
+ Fixed the calculation of row_factor in png_check_chunk_length
+ (reported by Thuan Pham in SourceForge issue #278)
+ Added missing parentheses to a macro definition
+ (suggested by "irwir" in GitHub issue #216)
+
+Version 1.6.36 [December 1, 2018]
+ Optimized png_do_expand_palette for ARM processors.
+ Improved performance by around 10-22% on a recent ARM Chromebook.
+ (Contributed by Richard Townsend, ARM Holdings)
+ Fixed manipulation of machine-specific optimization options.
+ (Contributed by Vicki Pfau)
+ Used memcpy instead of manual pointer arithmetic on Intel SSE2.
+ (Contributed by Samuel Williams)
+ Fixed build errors with MSVC on ARM64.
+ (Contributed by Zhijie Liang)
+ Fixed detection of libm in CMakeLists.
+ (Contributed by Cameron Cawley)
+ Fixed incorrect creation of pkg-config file in CMakeLists.
+ (Contributed by Kyle Bentley)
+ Fixed the CMake build on Windows MSYS by avoiding symlinks.
+ Fixed a build warning on OpenBSD.
+ (Contributed by Theo Buehler)
+ Fixed various typos in comments.
+ (Contributed by "luz.paz")
+ Raised the minimum required CMake version from 3.0.2 to 3.1.
+ Removed yet more of the vestigial support for pre-ANSI C compilers.
+ Removed ancient makefiles for ancient systems that have been broken
+ across all previous libpng-1.6.x versions.
+ Removed the Y2K compliance statement and the export control
+ information.
+ Applied various code style and documentation fixes.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe)
-or to glennrp at users.sourceforge.net
-
-Glenn R-P
-*/
+to subscribe).
diff --git a/com32/lib/libpng/LICENSE b/com32/lib/libpng/LICENSE
index e5561c22..62ab8e48 100644
--- a/com32/lib/libpng/LICENSE
+++ b/com32/lib/libpng/LICENSE
@@ -1,111 +1,134 @@
-
-This copy of the libpng notices is provided for your convenience. In case of
-any discrepancy between this copy and the notices in the file png.h that is
-included in the libpng distribution, the latter shall prevail.
-
-COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
-
-If you modify libpng you may insert additional notices immediately following
-this sentence.
-
-This code is released under the libpng license.
-
-libpng versions 1.2.6, August 15, 2004, through 1.2.44, June 26, 2010, are
-Copyright (c) 2004, 2006-2009 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-1.2.5
-with the following individual added to the list of Contributing Authors
-
- Cosmin Truta
-
-libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
-Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-1.0.6
-with the following individuals added to the list of Contributing Authors
-
- Simon-Pierre Cadieux
- Eric S. Raymond
- Gilles Vollant
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
+=========================================
+
+PNG Reference Library License version 2
+---------------------------------------
+
+ * Copyright (c) 1995-2018 The PNG Reference Library Authors.
+ * Copyright (c) 2018 Cosmin Truta.
+ * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
+ * Copyright (c) 1996-1997 Andreas Dilger.
+ * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+
+The software is supplied "as is", without warranty of any kind,
+express or implied, including, without limitation, the warranties
+of merchantability, fitness for a particular purpose, title, and
+non-infringement. In no even shall the Copyright owners, or
+anyone distributing the software, be liable for any damages or
+other liability, whether in contract, tort or otherwise, arising
+from, out of, or in connection with the software, or the use or
+other dealings in the software, even if advised of the possibility
+of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute
+this software, or portions hereof, for any purpose, without fee,
+subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you
+ must not claim that you wrote the original software. If you
+ use this software in a product, an acknowledgment in the product
+ documentation would be appreciated, but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must
+ not be misrepresented as being the original software.
+
+ 3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
+
+
+PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
+-----------------------------------------------------------------------
+
+libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are
+Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
+derived from libpng-1.0.6, and are distributed according to the same
+disclaimer and license as libpng-1.0.6 with the following individuals
+added to the list of Contributing Authors:
+
+ Simon-Pierre Cadieux
+ Eric S. Raymond
+ Mans Rullgard
+ Cosmin Truta
+ Gilles Vollant
+ James Yu
+ Mandar Sahastrabuddhe
+ Google Inc.
+ Vadim Barkov
and with the following additions to the disclaimer:
- There is no warranty against interference with your enjoyment of the
- library or against infringement. There is no warranty that our
- efforts or the library will fulfill any of your particular purposes
- or needs. This library is provided with all faults, and the entire
- risk of satisfactory quality, performance, accuracy, and effort is with
- the user.
+ There is no warranty against interference with your enjoyment of
+ the library or against infringement. There is no warranty that our
+ efforts or the library will fulfill any of your particular purposes
+ or needs. This library is provided with all faults, and the entire
+ risk of satisfactory quality, performance, accuracy, and effort is
+ with the user.
+
+Some files in the "contrib" directory and some configure-generated
+files that are distributed with libpng have other copyright owners, and
+are released under other open source licenses.
libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
-Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
-distributed according to the same disclaimer and license as libpng-0.96,
-with the following individuals added to the list of Contributing Authors:
+Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
+libpng-0.96, and are distributed according to the same disclaimer and
+license as libpng-0.96, with the following individuals added to the
+list of Contributing Authors:
- Tom Lane
- Glenn Randers-Pehrson
- Willem van Schaik
+ Tom Lane
+ Glenn Randers-Pehrson
+ Willem van Schaik
libpng versions 0.89, June 1996, through 0.96, May 1997, are
-Copyright (c) 1996, 1997 Andreas Dilger
-Distributed according to the same disclaimer and license as libpng-0.88,
-with the following individuals added to the list of Contributing Authors:
+Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
+and are distributed according to the same disclaimer and license as
+libpng-0.88, with the following individuals added to the list of
+Contributing Authors:
- John Bowler
- Kevin Bracey
- Sam Bushell
- Magnus Holmgren
- Greg Roelofs
- Tom Tanner
+ John Bowler
+ Kevin Bracey
+ Sam Bushell
+ Magnus Holmgren
+ Greg Roelofs
+ Tom Tanner
+
+Some files in the "scripts" directory have other copyright owners,
+but are released under this license.
libpng versions 0.5, May 1995, through 0.88, January 1996, are
-Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
For the purposes of this copyright and license, "Contributing Authors"
is defined as the following set of individuals:
- Andreas Dilger
- Dave Martindale
- Guy Eric Schalnat
- Paul Schmidt
- Tim Wegner
-
-The PNG Reference Library is supplied "AS IS". The Contributing Authors
-and Group 42, Inc. disclaim all warranties, expressed or implied,
-including, without limitation, the warranties of merchantability and of
-fitness for any purpose. The Contributing Authors and Group 42, Inc.
-assume no liability for direct, indirect, incidental, special, exemplary,
-or consequential damages, which may result from the use of the PNG
-Reference Library, even if advised of the possibility of such damage.
+ Andreas Dilger
+ Dave Martindale
+ Guy Eric Schalnat
+ Paul Schmidt
+ Tim Wegner
+
+The PNG Reference Library is supplied "AS IS". The Contributing
+Authors and Group 42, Inc. disclaim all warranties, expressed or
+implied, including, without limitation, the warranties of
+merchantability and of fitness for any purpose. The Contributing
+Authors and Group 42, Inc. assume no liability for direct, indirect,
+incidental, special, exemplary, or consequential damages, which may
+result from the use of the PNG Reference Library, even if advised of
+the possibility of such damage.
Permission is hereby granted to use, copy, modify, and distribute this
source code, or portions hereof, for any purpose, without fee, subject
to the following restrictions:
-1. The origin of this source code must not be misrepresented.
-
-2. Altered versions must be plainly marked as such and must not
- be misrepresented as being the original source.
-
-3. This Copyright notice may not be removed or altered from any
- source or altered source distribution.
-
-The Contributing Authors and Group 42, Inc. specifically permit, without
-fee, and encourage the use of this source code as a component to
-supporting the PNG file format in commercial products. If you use this
-source code in a product, acknowledgment is not required but would be
-appreciated.
-
-
-A "png_get_copyright" function is available, for convenient use in "about"
-boxes and the like:
-
- printf("%s",png_get_copyright(NULL));
+ 1. The origin of this source code must not be misrepresented.
-Also, the PNG logo (in PNG format, of course) is supplied in the
-files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+ 2. Altered versions must be plainly marked as such and must not
+ be misrepresented as being the original source.
-Libpng is OSI Certified Open Source Software. OSI Certified Open Source is a
-certification mark of the Open Source Initiative.
+ 3. This Copyright notice may not be removed or altered from any
+ source or altered source distribution.
-Glenn Randers-Pehrson
-glennrp at users.sourceforge.net
-June 26, 2010
+The Contributing Authors and Group 42, Inc. specifically permit,
+without fee, and encourage the use of this source code as a component
+to supporting the PNG file format in commercial products. If you use
+this source code in a product, acknowledgment is not required but would
+be appreciated.
diff --git a/com32/lib/libpng/README b/com32/lib/libpng/README
index ff7ac1f1..e41e0f54 100644
--- a/com32/lib/libpng/README
+++ b/com32/lib/libpng/README
@@ -1,19 +1,16 @@
-README for libpng version 1.2.44 - June 26, 2010 (shared library 12.0)
-See the note about version numbers near the top of png.h
+README for libpng version 1.6.36 - December 1, 2018
+===================================================
+See the note about version numbers near the top of png.h.
See INSTALL for instructions on how to install libpng.
-Libpng comes in several distribution formats. Get libpng-*.tar.gz,
-libpng-*.tar.xz, or libpng-*.tar.bz2 if you want UNIX-style line
-endings in the text files, or lpng*.7z or lpng*.zip if you want DOS-style
-line endings. You can get UNIX-style line endings from the *.zip file
-by using "unzip -a" but there seems to be no simple way to recover
-UNIX-style line endings from the *.7z file. The *.tar.xz file is
-recommended for *NIX users instead.
+Libpng comes in several distribution formats. Get libpng-*.tar.gz or
+libpng-*.tar.xz or if you want UNIX-style line endings in the text
+files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
Version 0.89 was the first official release of libpng. Don't let the
-fact that it's the first release fool you. The libpng library has been in
-extensive use and testing since mid-1995. By late 1997 it had
+fact that it's the first release fool you. The libpng library has been
+in extensive use and testing since mid-1995. By late 1997 it had
finally gotten to the stage where there hadn't been significant
changes to the API in some time, and people have a bad feeling about
libraries with versions < 1.0. Version 1.0.0 was released in
@@ -27,18 +24,25 @@ earlier versions if you are using a shared library. The type of the
png_uint_32, which will affect shared-library applications that use
this function.
-To avoid problems with changes to the internals of png_info_struct,
+To avoid problems with changes to the internals of the png info_struct,
new APIs have been made available in 0.95 to avoid direct application
access to info_ptr. These functions are the png_set_<chunk> and
png_get_<chunk> functions. These functions should be used when
accessing/storing the info_struct data, rather than manipulating it
directly, to avoid such problems in the future.
-It is important to note that the APIs do not make current programs
+It is important to note that the APIs did not make current programs
that access the info struct directly incompatible with the new
-library. However, it is strongly suggested that new programs use
-the new APIs (as shown in example.c and pngtest.c), and older programs
-be converted to the new format, to facilitate upgrades in the future.
+library, through libpng-1.2.x. In libpng-1.4.x, which was meant to
+be a transitional release, members of the png_struct and the
+info_struct can still be accessed, but the compiler will issue a
+warning about deprecated usage. Since libpng-1.5.0, direct access
+to these structs is not allowed, and the definitions of the structs
+reside in private pngstruct.h and pnginfo.h header files that are not
+accessible to applications. It is strongly suggested that new
+programs use the new APIs (as shown in example.c and pngtest.c), and
+older programs be converted to the new format, to facilitate upgrades
+in the future.
****
Additions since 0.90 include the ability to compile libpng as a
@@ -57,101 +61,71 @@ the library action on the detection of chunk CRC errors. It is possible
to set different actions based on whether the CRC error occurred in a
critical or an ancillary chunk.
-The changes made to the library, and bugs fixed are based on discussions
-on the png-mng-implement mailing list and not on material submitted
-privately to Guy, Andreas, or Glenn. They will forward any good
-suggestions to the list.
-
-For a detailed description on using libpng, read libpng.txt. For
-examples of libpng in a program, see example.c and pngtest.c. For usage
-information and restrictions (what little they are) on libpng, see
-png.h. For a description on using zlib (the compression library used by
-libpng) and zlib's restrictions, see zlib.h
+For a detailed description on using libpng, read libpng-manual.txt.
+For examples of libpng in a program, see example.c and pngtest.c. For
+usage information and restrictions (what little they are) on libpng,
+see png.h. For a description on using zlib (the compression library
+used by libpng) and zlib's restrictions, see zlib.h
I have included a general makefile, as well as several machine and
-compiler specific ones, but you may have to modify one for your own needs.
+compiler specific ones, but you may have to modify one for your own
+needs.
You should use zlib 1.0.4 or later to run this, but it MAY work with
versions as old as zlib 0.95. Even so, there are bugs in older zlib
versions which can cause the output of invalid compression streams for
-some images. You will definitely need zlib 1.0.4 or later if you are
-taking advantage of the MS-DOS "far" structure allocation for the small
-and medium memory models. You should also note that zlib is a
-compression library that is useful for more things than just PNG files.
-You can use zlib as a drop-in replacement for fread() and fwrite() if
-you are so inclined.
+some images.
+
+You should also note that zlib is a compression library that is useful
+for more things than just PNG files. You can use zlib as a drop-in
+replacement for fread() and fwrite(), if you are so inclined.
zlib should be available at the same place that libpng is, or at
-ftp://ftp.simplesystems.org/pub/png/src/
+https://zlib.net.
You may also want a copy of the PNG specification. It is available
as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
-these at http://www.libpng.org/pub/png/pngdocs.html
+these at http://www.libpng.org/pub/png/pngdocs.html .
-This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
-at GO GRAPHSUP. If you can't find it in any of those places,
-e-mail me, and I'll help you find it.
+This code is currently being archived at libpng.sourceforge.io in the
+[DOWNLOAD] area, and at http://libpng.download/src .
-If you have any code changes, requests, problems, etc., please e-mail
-them to me. Also, I'd appreciate any make files or project files,
-and any modifications you needed to make to get libpng to compile,
-along with a #define variable to tell what compiler/system you are on.
-If you needed to add transformations to libpng, or wish libpng would
-provide the image in a different way, drop me a note (and code, if
-possible), so I can consider supporting the transformation.
-Finally, if you get any warning messages when compiling libpng
-(note: not zlib), and they are easy to fix, I'd appreciate the
-fix. Please mention "libpng" somewhere in the subject line. Thanks.
-
-This release was created and will be supported by myself (of course
-based in a large way on Guy's and Andreas' earlier work), and the PNG
+This release, based in a large way on Glenn's, Guy's and Andreas'
+earlier work, was created and will be supported by myself and the PNG
development group.
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit
+Send comments/corrections/commendations to png-mng-implement at
+lists.sourceforge.net (subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
-
-You can't reach Guy, the original libpng author, at the addresses
-given in previous versions of this document. He and Andreas will
-read mail addressed to the png-mng-implement list, however.
+to subscribe).
-Please do not send general questions about PNG. Send them to
-the (png-mng-misc at lists.sourceforge.net, subscription required, visit
+Send general questions about the PNG specification to png-mng-misc
+at lists.sourceforge.net (subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
-subscribe). On the other hand, please do not send libpng questions to
-that address, send them to me or to the png-mng-implement list. I'll
-get them in the end anyway. If you have a question about something
-in the PNG specification that is related to using libpng, send it
-to me. Send me any questions that start with "I was using libpng,
-and ...". If in doubt, send questions to me. I'll bounce them
-to others, if necessary.
-
-Please do not send suggestions on how to change PNG. We have
-been discussing PNG for twelve years now, and it is official and
-finished. If you have suggestions for libpng, however, I'll
-gladly listen. Even if your suggestion is not used immediately,
-it may be used later.
+subscribe).
Files in this distribution:
ANNOUNCE => Announcement of this version, with recent changes
+ AUTHORS => List of contributing authors
CHANGES => Description of changes between libpng versions
KNOWNBUG => List of known bugs and deficiencies
LICENSE => License to use and redistribute libpng
README => This file
TODO => Things not implemented in the current library
- Y2KINFO => Statement of Y2K compliance
+ TRADEMARK => Trademark information
example.c => Example code for using libpng functions
- libpng-*-*-diff.txt => Diff from previous release
- libpng.3 => manual page for libpng (includes libpng.txt)
- libpng.txt => Description of libpng and its functions
+ libpng.3 => manual page for libpng (includes libpng-manual.txt)
+ libpng-manual.txt => Description of libpng and its functions
libpngpf.3 => manual page for libpng's private functions
png.5 => manual page for the PNG format
png.c => Basic interface functions common to library
- png.h => Library function and interface declarations
- pngconf.h => System specific library configuration
+ png.h => Library function and interface declarations (public)
+ pngpriv.h => Library function and interface declarations (private)
+ pngconf.h => System specific library configuration (public)
+ pngstruct.h => png_struct declaration (private)
+ pnginfo.h => png_info struct declaration (private)
+ pngdebug.h => debugging macros (private)
pngerror.c => Error/warning message I/O functions
pngget.c => Functions for retrieving info from struct
pngmem.c => Memory handling functions
@@ -170,106 +144,40 @@ Files in this distribution:
pngwrite.c => High-level write functions
pngwtran.c => Write data transformations
pngwutil.c => Write utility functions
+ arm => Contains optimized code for the ARM platform
+ powerpc => Contains optimized code for the PowerPC platform
contrib => Contributions
+ arm-neon => Optimized code for ARM-NEON platform
+ powerpc-vsx => Optimized code for POWERPC-VSX platform
+ examples => Example programs
gregbook => source code for PNG reading and writing, from
Greg Roelofs' "PNG: The Definitive Guide",
O'Reilly, 1999
- msvctest => Builds and runs pngtest using a MSVC workspace
- pngminim => Simple pnm2pngm and png2pnmm programs
- pngminus => Simple pnm2png and png2pnm programs
- pngsuite => Test images
- visupng => Contains a MSVC workspace for VisualPng
+ libtests => Test programs
+ mips-msa => Optimized code for MIPS-MSA platform
+ pngminim => Minimal decoder, encoder, and progressive decoder
+ programs demonstrating use of pngusr.dfa
+ pngminus => Simple pnm2png and png2pnm programs
+ pngsuite => Test images
+ testpngs
+ tools => Various tools
+ visupng => Contains a MSVC workspace for VisualPng
+ intel => Optimized code for INTEL-SSE2 platform
+ mips => Optimized code for MIPS platform
projects => Contains project files and workspaces for
building a DLL
- beos => Contains a Beos workspace for building libpng
- c5builder => Contains a Borland workspace for building
- libpng and zlib
- netware.txt => Contains instructions for downloading a set
- of project files for building libpng and
- zlib on Netware.
- visualc6 => Contains a Microsoft Visual C++ (MSVC)
+ owatcom => Contains a WATCOM project for building libpng
+ visualc71 => Contains a Microsoft Visual C++ (MSVC)
+ workspace for building libpng and zlib
+ vstudio => Contains a Microsoft Visual C++ (MSVC)
workspace for building libpng and zlib
- wince.txt => Contains instructions for downloading a
- Microsoft Visual C++ (Windows CD Toolkit)
- workspace for building libpng and zlib on
- WindowsCE
- xcode => Contains xcode project files
scripts => Directory containing scripts for building libpng:
- descrip.mms => VMS makefile for MMS or MMK
- makefile.std => Generic UNIX makefile (cc, creates static
- libpng.a)
- makefile.elf => Linux/ELF gcc makefile symbol versioning,
- creates libpng12.so.0.1.2.44)
- makefile.linux => Linux/ELF makefile (gcc, creates
- libpng12.so.0.1.2.44)
- makefile.gcmmx => Linux/ELF makefile (gcc, creates
- libpng12.so.0.1.2.44, previously
- used assembler code tuned for Intel MMX
- platform)
- makefile.gcc => Generic makefile (gcc, creates static
- libpng.a)
- makefile.knr => Archaic UNIX Makefile that converts files
- with ansi2knr (Requires ansi2knr.c from
- ftp://ftp.cs.wisc.edu/ghost)
- makefile.aix => AIX makefile
- makefile.cygwin => Cygwin/gcc makefile
- makefile.darwin => Darwin makefile
- makefile.dec => DEC Alpha UNIX makefile
- makefile.freebsd => FreeBSD makefile
- makefile.hpgcc => HPUX makefile using gcc
- makefile.hpux => HPUX (10.20 and 11.00) makefile
- makefile.hp64 => HPUX (10.20 and 11.00) makefile, 64 bit
- makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2
- (static)
- makefile.intel => Intel C/C++ version 4.0 and later
- libpng.icc => Project file, IBM VisualAge/C++ 4.0 or later
- makefile.netbsd => NetBSD/cc makefile, makes libpng.so.
- makefile.ne12bsd => NetBSD/cc makefile, makes libpng12.so
- makefile.openbsd => OpenBSD makefile
- makefile.sgi => Silicon Graphics IRIX (cc, creates static lib)
- makefile.sggcc => Silicon Graphics
- (gcc, creates libpng12.so.0.1.2.44)
- makefile.sunos => Sun makefile
- makefile.solaris => Solaris 2.X makefile
- (gcc, creates libpng12.so.0.1.2.44)
- makefile.so9 => Solaris 9 makefile
- (gcc, creates libpng12.so.0.1.2.44)
- makefile.32sunu => Sun Ultra 32-bit makefile
- makefile.64sunu => Sun Ultra 64-bit makefile
- makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
- makefile.mips => MIPS makefile
- makefile.acorn => Acorn makefile
- makefile.amiga => Amiga makefile
- smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC
- compiler (Requires SCOPTIONS, copied from
- scripts/SCOPTIONS.ppc)
- makefile.atari => Atari makefile
- makefile.beos => BEOS makefile for X86
- makefile.bor => Borland makefile (uses bcc)
- makefile.bc32 => 32-bit Borland C++ (all modules compiled in C mode)
- makefile.tc3 => Turbo C 3.0 makefile
- makefile.dj2 => DJGPP 2 makefile
- makefile.msc => Microsoft C makefile
- makefile.vcawin32=> makefile for Microsoft Visual C++ 5.0 and
- later (previously used assembler code tuned
- for Intel MMX platform)
- makefile.vcwin32 => makefile for Microsoft Visual C++ 4.0 and
- later (does not use assembler code)
- makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def)
- pngos2.def => OS/2 module definition file used by makefile.os2
- makefile.watcom => Watcom 10a+ Makefile, 32-bit flat memory model
- makevms.com => VMS build script
- SCOPTIONS.ppc => Used with smakefile.ppc
-
-Good luck, and happy coding.
-
--Glenn Randers-Pehrson (current maintainer, since 1998)
- Internet: glennrp at users.sourceforge.net
+ (see scripts/README.txt for the list of scripts)
--Andreas Eric Dilger (former maintainer, 1996-1997)
- Internet: adilger at enel.ucalgary.ca
- Web: http://members.shaw.ca/adilger/
+Good luck, and happy coding!
--Guy Eric Schalnat (original author and former maintainer, 1995-1996)
- (formerly of Group 42, Inc)
- Internet: gschal at infinet.com
+ * Cosmin Truta (current maintainer, since 2018)
+ * Glenn Randers-Pehrson (former maintainer, 1998-2018)
+ * Andreas Eric Dilger (former maintainer, 1996-1997)
+ * Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc.)
diff --git a/com32/lib/libpng/TODO b/com32/lib/libpng/TODO
index face7658..562dab06 100644
--- a/com32/lib/libpng/TODO
+++ b/com32/lib/libpng/TODO
@@ -1,25 +1,23 @@
TODO - list of things to do for libpng:
-Final bug fixes.
-Improve API by hiding the png_struct and png_info structs.
-Finish work on the no-floating-point version (including gamma compensation)
-Better C++ wrapper/full C++ implementation?
-Fix problem with C++ and EXTERN "C".
-cHRM transformation.
-Improve setjmp/longjmp usage or remove it in favor of returning error codes.
-Add "grayscale->palette" transformation and "palette->grayscale" detection.
-Improved dithering.
-Multi-lingual error and warning message support.
-Complete sRGB transformation (presently it simply uses gamma=0.45455).
-Man pages for function calls.
-Better documentation.
-Better filter selection
- (counting huffman bits/precompression? filter inertia? filter costs?).
-Histogram creation.
-Text conversion between different code pages (Latin-1 -> Mac and DOS).
-Should we always malloc 2^bit_depth PLTE/tRNS/hIST entries for safety?
-Build gamma tables using fixed point (and do away with floating point entirely).
-Use greater precision when changing to linear gamma for compositing against
- background and doing rgb-to-gray transformation.
-Investigate pre-incremented loop counters and other loop constructions.
-Add interpolated method of handling interlacing.
+* Fix all defects (duh!)
+* Better C++ wrapper / full C++ implementation (?)
+* Fix the problems with C++ and 'extern "C"'.
+* cHRM transformation.
+* Palette creation.
+* "grayscale->palette" transformation and "palette->grayscale" detection.
+* Improved dithering.
+* Multi-lingual error and warning message support.
+* Complete sRGB transformation. (Currently it simply uses gamma=0.45455.)
+* Man pages for function calls.
+* Better documentation.
+* Better filter selection
+ (e.g., counting huffman bits/precompression; filter inertia; filter costs).
+* Histogram creation.
+* Text conversion between different code pages (e.g., Latin-1 -> Mac).
+* Avoid building gamma tables whenever possible.
+* Greater precision in changing to linear gamma for compositing against
+ background, and in doing rgb-to-gray transformations.
+* Investigate pre-incremented loop counters and other loop constructions.
+* Interpolated method of handling interlacing.
+* More validations for libpng transformations.
diff --git a/com32/lib/libpng/example.c b/com32/lib/libpng/example.c
index 49b87242..2e2afaaf 100644
--- a/com32/lib/libpng/example.c
+++ b/com32/lib/libpng/example.c
@@ -2,16 +2,20 @@
#if 0 /* in case someone actually tries to compile this */
/* example.c - an example of using libpng
- * Last changed in libpng 1.2.37 [June 4, 2009]
- * This file has been placed in the public domain by the authors.
- * Maintained 1998-2010 Glenn Randers-Pehrson
- * Maintained 1996, 1997 Andreas Dilger)
- * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * Maintained 2018 Cosmin Truta
+ * Maintained 1998-2016 Glenn Randers-Pehrson
+ * Maintained 1996-1997 Andreas Dilger
+ * Written 1995-1996 Guy Eric Schalnat, Group 42, Inc.
+ *
+ * To the extent possible under law, the authors have waived
+ * all copyright and related or neighboring rights to this file.
+ * This work is published from: United States, Canada.
*/
/* This is an example of how to use libpng to read and write PNG files.
- * The file libpng.txt is much more verbose then this. If you have not
- * read it, do so first. This was designed to be a starting point of an
+ * The file libpng-manual.txt is much more verbose then this. If you have
+ * not read it, do so first. This was designed to be a starting point of an
* implementation. This is not officially part of libpng, is hereby placed
* in the public domain, and therefore does not require a copyright notice.
*
@@ -22,23 +26,209 @@
* see also the programs in the contrib directory.
*/
-#include "png.h"
+/* The simple, but restricted approach to reading a PNG file or data stream
+ * requires just two function calls, as in the following complete program.
+ * Writing a file needs just one function call, so long as the data has an
+ * appropriate layout.
+ *
+ * The following code reads PNG image data from a file and writes it, in a
+ * potentially new format, to a new file. While this code will compile, there
+ * is minimal (insufficient) error checking. For a more realistic version,
+ * see contrib/examples/pngtopng.c
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <png.h>
+#include <zlib.h>
+
+int main(int argc, const char **argv)
+{
+ if (argc == 3)
+ {
+ png_image image; /* The control structure used by libpng */
+
+ /* Initialize the 'png_image' structure. */
+ memset(&image, 0, (sizeof image));
+ image.version = PNG_IMAGE_VERSION;
+
+ /* The first argument is the file to read: */
+ if (png_image_begin_read_from_file(&image, argv[1]) != 0)
+ {
+ png_bytep buffer;
+
+ /* Set the format in which to read the PNG file; this code chooses a
+ * simple sRGB format with a non-associated alpha channel, adequate to
+ * store most images.
+ */
+ image.format = PNG_FORMAT_RGBA;
+
+ /* Now allocate enough memory to hold the image in this format; the
+ * PNG_IMAGE_SIZE macro uses the information about the image (width,
+ * height and format) stored in 'image'.
+ */
+ buffer = malloc(PNG_IMAGE_SIZE(image));
+
+ /* If enough memory was available, read the image in the desired
+ * format, then write the result out to the new file. 'background' is
+ * not necessary when reading the image, because the alpha channel is
+ * preserved; if it were to be removed, for example if we requested
+ * PNG_FORMAT_RGB, then either a solid background color would have to
+ * be supplied, or the output buffer would have to be initialized to
+ * the actual background of the image.
+ *
+ * The fourth argument to png_image_finish_read is the 'row_stride' -
+ * this is the number of components allocated for the image in each
+ * row. It has to be at least as big as the value returned by
+ * PNG_IMAGE_ROW_STRIDE, but if you just allocate space for the
+ * default, minimum size, using PNG_IMAGE_SIZE as above, you can pass
+ * zero.
+ *
+ * The final argument is a pointer to a buffer for the colormap;
+ * colormaps have exactly the same format as a row of image pixels
+ * (so you choose what format to make the colormap by setting
+ * image.format). A colormap is only returned if
+ * PNG_FORMAT_FLAG_COLORMAP is also set in image.format, so in this
+ * case NULL is passed as the final argument. If you do want to force
+ * all images into an index/color-mapped format, then you can use:
+ *
+ * PNG_IMAGE_COLORMAP_SIZE(image)
+ *
+ * to find the maximum size of the colormap in bytes.
+ */
+ if (buffer != NULL &&
+ png_image_finish_read(&image, NULL/*background*/, buffer,
+ 0/*row_stride*/, NULL/*colormap*/) != 0)
+ {
+ /* Now write the image out to the second argument. In the write
+ * call 'convert_to_8bit' allows 16-bit data to be squashed down to
+ * 8 bits; this isn't necessary here because the original read was
+ * to the 8-bit format.
+ */
+ if (png_image_write_to_file(&image, argv[2], 0/*convert_to_8bit*/,
+ buffer, 0/*row_stride*/, NULL/*colormap*/) != 0)
+ {
+ /* The image has been written successfully. */
+ exit(0);
+ }
+ }
+ else
+ {
+ /* Calling png_image_free is optional unless the simplified API was
+ * not run to completion. In this case, if there wasn't enough
+ * memory for 'buffer', we didn't complete the read, so we must
+ * free the image:
+ */
+ if (buffer == NULL)
+ png_image_free(&image);
+ else
+ free(buffer);
+ }
+
+ /* Something went wrong reading or writing the image. libpng stores a
+ * textual message in the 'png_image' structure:
+ */
+ fprintf(stderr, "pngtopng: error: %s\n", image.message);
+ exit(1);
+ }
+
+ fprintf(stderr, "pngtopng: usage: pngtopng input-file output-file\n");
+ exit(2);
+}
+
+/* That's it ;-) Of course you probably want to do more with PNG files than
+ * just converting them all to 32-bit RGBA PNG files; you can do that between
+ * the call to png_image_finish_read and png_image_write_to_file. You can also
+ * ask for the image data to be presented in a number of different formats.
+ * You do this by simply changing the 'format' parameter set before allocating
+ * the buffer.
+ *
+ * The format parameter consists of five flags that define various aspects of
+ * the image. You can simply add these together to get the format, or you can
+ * use one of the predefined macros from png.h (as above):
+ *
+ * PNG_FORMAT_FLAG_COLOR: if set, the image will have three color components
+ * per pixel (red, green and blue); if not set, the image will just have one
+ * luminance (grayscale) component.
+ *
+ * PNG_FORMAT_FLAG_ALPHA: if set, each pixel in the image will have an
+ * additional alpha value; a linear value that describes the degree the
+ * image pixel covers (overwrites) the contents of the existing pixel on the
+ * display.
+ *
+ * PNG_FORMAT_FLAG_LINEAR: if set, the components of each pixel will be
+ * returned as a series of 16-bit linear values; if not set, the components
+ * will be returned as a series of 8-bit values encoded according to the
+ * sRGB standard. The 8-bit format is the normal format for images intended
+ * for direct display, because almost all display devices do the inverse of
+ * the sRGB transformation to the data they receive. The 16-bit format is
+ * more common for scientific data and image data that must be further
+ * processed; because it is linear, simple math can be done on the component
+ * values. Regardless of the setting of this flag, the alpha channel is
+ * always linear, although it will be 8 bits or 16 bits wide as specified by
+ * the flag.
+ *
+ * PNG_FORMAT_FLAG_BGR: if set, the components of a color pixel will be
+ * returned in the order blue, then green, then red. If not set, the pixel
+ * components are in the order red, then green, then blue.
+ *
+ * PNG_FORMAT_FLAG_AFIRST: if set, the alpha channel (if present) precedes the
+ * color or grayscale components. If not set, the alpha channel follows the
+ * components.
+ *
+ * You do not have to read directly from a file. You can read from memory or,
+ * on systems that support it, from a <stdio.h> FILE*. This is controlled by
+ * the particular png_image_read_from_ function you call at the start.
+ * Likewise, on write, you can write to a FILE* if your system supports it.
+ * Check the macro PNG_STDIO_SUPPORTED to see if stdio support has been
+ * included in your libpng build.
+ *
+ * If you read 16-bit (PNG_FORMAT_FLAG_LINEAR) data, you may need to write it
+ * in the 8-bit format for display. You do this by setting the convert_to_8bit
+ * flag to 'true'.
+ *
+ * Don't repeatedly convert between the 8-bit and 16-bit forms. There is
+ * significant data loss when 16-bit data is converted to the 8-bit encoding,
+ * and the current libpng implementation of conversion to 16-bit is also
+ * significantly lossy. The latter will be fixed in the future, but the former
+ * is unavoidable - the 8-bit format just doesn't have enough resolution.
+ */
+
+/* If your program needs more information from the PNG data it reads, or if you
+ * need to do more complex transformations, or minimize transformations, on the
+ * data you read, then you must use one of the several lower level libpng
+ * interfaces.
+ *
+ * All these interfaces require that you do your own error handling - your
+ * program must be able to arrange for control to return to your own code, any
+ * time libpng encounters a problem. There are several ways to do this, but
+ * the standard way is to use the <setjmp.h> interface to establish a return
+ * point within your own code. You must do this if you do not use the
+ * simplified interface (above).
+ *
+ * The first step is to include the header files you need, including the libpng
+ * header file. Include any standard headers and feature test macros your
+ * program requires before including png.h:
+ */
+#include <png.h>
/* The png_jmpbuf() macro, used in error handling, became available in
* libpng version 1.0.6. If you want to be able to run your code with older
* versions of libpng, you must define the macro yourself (but only if it
- * is not already defined by libpng!).
+ * is not already defined by libpng!)
*/
#ifndef png_jmpbuf
-# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+# define png_jmpbuf(png_ptr) ((png_ptr)->png_jmpbuf)
#endif
/* Check to see if a file is a PNG file using png_sig_cmp(). png_sig_cmp()
- * returns zero if the image is a PNG and nonzero if it isn't a PNG.
+ * returns zero if the image is a PNG, and nonzero otherwise.
*
* The function check_if_png() shown here, but not used, returns nonzero (true)
- * if the file can be opened and is a PNG, 0 (false) otherwise.
+ * if the file can be opened and is a PNG, and 0 (false) otherwise.
*
* If this call is successful, and you are going to keep the file open,
* you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
@@ -51,7 +241,7 @@
*
* Many applications already read the first 2 or 4 bytes from the start
* of the image to determine the file type, so it would be easiest just
- * to pass the bytes to png_sig_cmp() or even skip that if you know
+ * to pass the bytes to png_sig_cmp(), or even skip that if you know
* you have a PNG file, and call png_set_sig_bytes().
*/
#define PNG_BYTES_TO_CHECK 4
@@ -63,14 +253,14 @@ int check_if_png(char *file_name, FILE **fp)
if ((*fp = fopen(file_name, "rb")) == NULL)
return 0;
- /* Read in some of the signature bytes */
+ /* Read in some of the signature bytes. */
if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
return 0;
/* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
- Return nonzero (true) if they match */
-
- return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
+ * Return nonzero (true) if they match.
+ */
+ return(!png_sig_cmp(buf, 0, PNG_BYTES_TO_CHECK));
}
/* Read a PNG file. You may want to return an error code if the read
@@ -80,11 +270,11 @@ int check_if_png(char *file_name, FILE **fp)
* some or all of the magic bytes read - see comments above).
*/
#ifdef open_file /* prototype 1 */
-void read_png(char *file_name) /* We need to open the file */
+void read_png(char *file_name) /* We need to open the file */
{
png_structp png_ptr;
png_infop info_ptr;
- unsigned int sig_read = 0;
+ int sig_read = 0;
png_uint_32 width, height;
int bit_depth, color_type, interlace_type;
FILE *fp;
@@ -93,7 +283,7 @@ void read_png(char *file_name) /* We need to open the file */
return (ERROR);
#else no_open_file /* prototype 2 */
-void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
+void read_png(FILE *fp, int sig_read) /* File is already open */
{
png_structp png_ptr;
png_infop info_ptr;
@@ -105,10 +295,10 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also supply the
* the compiler header file version, so that we know if the application
- * was compiled with a compatible version of the library. REQUIRED
+ * was compiled with a compatible version of the library. REQUIRED.
*/
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
if (png_ptr == NULL)
{
@@ -121,7 +311,7 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
if (info_ptr == NULL)
{
fclose(fp);
- png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
+ png_destroy_read_struct(&png_ptr, NULL, NULL);
return (ERROR);
}
@@ -129,53 +319,51 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
* the normal method of doing things with libpng). REQUIRED unless you
* set up your own error handlers in the png_create_read_struct() earlier.
*/
-
if (setjmp(png_jmpbuf(png_ptr)))
{
- /* Free all of the memory associated with the png_ptr and info_ptr */
- png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+ /* Free all of the memory associated with the png_ptr and info_ptr. */
+ png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fclose(fp);
- /* If we get here, we had a problem reading the file */
+ /* If we get here, we had a problem reading the file. */
return (ERROR);
}
- /* One of the following I/O initialization methods is REQUIRED */
+ /* One of the following I/O initialization methods is REQUIRED. */
#ifdef streams /* PNG file I/O method 1 */
- /* Set up the input control if you are using standard C streams */
+ /* Set up the input control if you are using standard C streams. */
png_init_io(png_ptr, fp);
#else no_streams /* PNG file I/O method 2 */
/* If you are using replacement read functions, instead of calling
- * png_init_io() here you would call:
+ * png_init_io(), you would call:
*/
png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn);
- /* where user_io_ptr is a structure you want available to the callbacks */
+ /* where user_io_ptr is a structure you want available to the callbacks. */
#endif no_streams /* Use only one I/O method! */
/* If we have already read some of the signature */
png_set_sig_bytes(png_ptr, sig_read);
#ifdef hilevel
- /*
- * If you have enough memory to read in the entire image at once,
+ /* If you have enough memory to read in the entire image at once,
* and you need to specify only transforms that can be controlled
* with one of the PNG_TRANSFORM_* bits (this presently excludes
- * dithering, filling, setting background, and doing gamma
+ * quantizing, filling, setting background, and doing gamma
* adjustment), then you can read the entire image (including
* pixels) into the info structure with this call:
*/
- png_read_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+ png_read_png(png_ptr, info_ptr, png_transforms, NULL);
#else
- /* OK, you're doing it the hard way, with the lower-level functions */
+ /* OK, you're doing it the hard way, with the lower-level functions. */
/* The call to png_read_info() gives us all of the information from the
- * PNG file before the first IDAT (image data chunk). REQUIRED
+ * PNG file before the first IDAT (image data chunk). REQUIRED.
*/
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
- &interlace_type, int_p_NULL, int_p_NULL);
+ &interlace_type, NULL, NULL);
/* Set up the data transformations you want. Note that these are all
* optional. Only call them if you want/need them. Many of the
@@ -183,221 +371,219 @@ void read_png(FILE *fp, unsigned int sig_read) /* File is already open */
* are mutually exclusive.
*/
- /* Tell libpng to strip 16 bit/color files down to 8 bits/color */
+ /* Tell libpng to strip 16 bits/color files down to 8 bits/color.
+ * Use accurate scaling if it's available, otherwise just chop off the
+ * low byte.
+ */
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
+ png_set_scale_16(png_ptr);
+#else
png_set_strip_16(png_ptr);
+#endif
/* Strip alpha bytes from the input data without combining with the
* background (not recommended).
*/
png_set_strip_alpha(png_ptr);
- /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
+ /* Extract multiple pixels with bit depths of 1, 2 or 4 from a single
* byte into separate bytes (useful for paletted and grayscale images).
*/
png_set_packing(png_ptr);
/* Change the order of packed pixels to least significant bit first
- * (not useful if you are using png_set_packing). */
+ * (not useful if you are using png_set_packing).
+ */
png_set_packswap(png_ptr);
- /* Expand paletted colors into true RGB triplets */
+ /* Expand paletted colors into true RGB triplets. */
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
- /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
+ /* Expand grayscale images to the full 8 bits from 1, 2 or 4 bits/pixel. */
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand_gray_1_2_4_to_8(png_ptr);
/* Expand paletted or RGB images with transparency to full alpha channels
* so the data will be available as RGBA quartets.
*/
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS) != 0)
png_set_tRNS_to_alpha(png_ptr);
/* Set the background color to draw transparent and alpha images over.
- * It is possible to set the red, green, and blue components directly
- * for paletted images instead of supplying a palette index. Note that
+ * It is possible to set the red, green and blue components directly
+ * for paletted images, instead of supplying a palette index. Note that,
* even if the PNG file supplies a background, you are not required to
* use it - you should use the (solid) application background if it has one.
*/
-
png_color_16 my_background, *image_background;
- if (png_get_bKGD(png_ptr, info_ptr, &image_background))
+ if (png_get_bKGD(png_ptr, info_ptr, &image_background) != 0)
png_set_background(png_ptr, image_background,
- PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+ PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
else
png_set_background(png_ptr, &my_background,
- PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+ PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
- /* Some suggestions as to how to get a screen gamma value
+ /* Some suggestions as to how to get a screen gamma value.
*
* Note that screen gamma is the display_exponent, which includes
- * the CRT_exponent and any correction for viewing conditions
+ * the CRT_exponent and any correction for viewing conditions.
*/
if (/* We have a user-defined screen gamma value */)
- {
screen_gamma = user-defined screen_gamma;
- }
- /* This is one way that applications share the same screen gamma value */
+ /* This is one way that applications share the same screen gamma value. */
else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
- {
screen_gamma = atof(gamma_str);
- }
/* If we don't have another value */
else
{
- screen_gamma = 2.2; /* A good guess for a PC monitor in a dimly
- lit room */
- screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
+ screen_gamma = PNG_DEFAULT_sRGB; /* A good guess for a PC monitor
+ in a dimly lit room */
+ screen_gamma = PNG_GAMMA_MAC_18 or 1.0; /* Good guesses for Mac
+ systems */
}
/* Tell libpng to handle the gamma conversion for you. The final call
* is a good guess for PC generated images, but it should be configurable
- * by the user at run time by the user. It is strongly suggested that
- * your application support gamma correction.
+ * by the user at run time. Gamma correction support in your application
+ * is strongly recommended.
*/
int intent;
- if (png_get_sRGB(png_ptr, info_ptr, &intent))
- png_set_gamma(png_ptr, screen_gamma, 0.45455);
+ if (png_get_sRGB(png_ptr, info_ptr, &intent) != 0)
+ png_set_gamma(png_ptr, screen_gamma, PNG_DEFAULT_sRGB);
else
{
double image_gamma;
- if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
+ if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) != 0)
png_set_gamma(png_ptr, screen_gamma, image_gamma);
else
png_set_gamma(png_ptr, screen_gamma, 0.45455);
}
- /* Dither RGB files down to 8 bit palette or reduce palettes
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ /* Quantize RGB files down to 8-bit palette, or reduce palettes
* to the number of colors available on your screen.
*/
- if (color_type & PNG_COLOR_MASK_COLOR)
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
{
int num_palette;
png_colorp palette;
- /* This reduces the image to the application supplied palette */
+ /* This reduces the image to the application-supplied palette. */
if (/* We have our own palette */)
{
- /* An array of colors to which the image should be dithered */
+ /* An array of colors to which the image should be quantized. */
png_color std_color_cube[MAX_SCREEN_COLORS];
-
- png_set_dither(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
- MAX_SCREEN_COLORS, png_uint_16p_NULL, 0);
+ png_set_quantize(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
+ MAX_SCREEN_COLORS, NULL, 0);
}
- /* This reduces the image to the palette supplied in the file */
- else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
+ /* This reduces the image to the palette supplied in the file. */
+ else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette) != 0)
{
png_uint_16p histogram = NULL;
-
png_get_hIST(png_ptr, info_ptr, &histogram);
-
- png_set_dither(png_ptr, palette, num_palette,
- max_screen_colors, histogram, 0);
+ png_set_quantize(png_ptr, palette, num_palette,
+ max_screen_colors, histogram, 0);
}
}
+#endif /* READ_QUANTIZE */
- /* Invert monochrome files to have 0 as white and 1 as black */
+ /* Invert monochrome files to have 0 as white and 1 as black. */
png_set_invert_mono(png_ptr);
/* If you want to shift the pixel values from the range [0,255] or
* [0,65535] to the original [0,7] or [0,31], or whatever range the
* colors were originally in:
*/
- if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT) != 0)
{
png_color_8p sig_bit_p;
-
png_get_sBIT(png_ptr, info_ptr, &sig_bit_p);
png_set_shift(png_ptr, sig_bit_p);
}
- /* Flip the RGB pixels to BGR (or RGBA to BGRA) */
- if (color_type & PNG_COLOR_MASK_COLOR)
+ /* Flip the RGB pixels to BGR (or RGBA to BGRA). */
+ if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
png_set_bgr(png_ptr);
- /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+ /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR). */
png_set_swap_alpha(png_ptr);
- /* Swap bytes of 16 bit files to least significant byte first */
+ /* Swap bytes of 16-bit files to least significant byte first. */
png_set_swap(png_ptr);
- /* Add filler (or alpha) byte (before/after each RGB triplet) */
- png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
+ /* Add filler (or alpha) byte (before/after each RGB triplet). */
+ png_set_filler(png_ptr, 0xffff, PNG_FILLER_AFTER);
+#ifdef PNG_READ_INTERLACING_SUPPORTED
/* Turn on interlace handling. REQUIRED if you are not using
* png_read_image(). To see how to handle interlacing passes,
* see the png_read_row() method below:
*/
number_passes = png_set_interlace_handling(png_ptr);
+#else /* !READ_INTERLACING */
+ number_passes = 1;
+#endif /* READ_INTERLACING */
/* Optional call to gamma correct and add the background to the palette
* and update info structure. REQUIRED if you are expecting libpng to
- * update the palette for you (ie you selected such a transform above).
+ * update the palette for you (i.e. you selected such a transform above).
*/
png_read_update_info(png_ptr, info_ptr);
/* Allocate the memory to hold the image using the fields of info_ptr. */
-
- /* The easiest way to read the image: */
png_bytep row_pointers[height];
-
- /* Clear the pointer array */
for (row = 0; row < height; row++)
- row_pointers[row] = NULL;
-
+ row_pointers[row] = NULL; /* Clear the pointer array */
for (row = 0; row < height; row++)
row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
- info_ptr));
+ info_ptr));
- /* Now it's time to read the image. One of these methods is REQUIRED */
+ /* Now it's time to read the image. One of these methods is REQUIRED. */
#ifdef entire /* Read the entire image in one go */
png_read_image(png_ptr, row_pointers);
#else no_entire /* Read the image one or more scanlines at a time */
/* The other way to read images - deal with interlacing: */
-
for (pass = 0; pass < number_passes; pass++)
{
#ifdef single /* Read the image a single row at a time */
for (y = 0; y < height; y++)
- {
- png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL, 1);
- }
+ png_read_rows(png_ptr, &row_pointers[y], NULL, 1);
#else no_single /* Read the image several rows at a time */
for (y = 0; y < height; y += number_of_rows)
{
#ifdef sparkle /* Read the image using the "sparkle" effect. */
- png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL,
- number_of_rows);
+ png_read_rows(png_ptr, &row_pointers[y], NULL,
+ number_of_rows);
#else no_sparkle /* Read the image using the "rectangle" effect */
- png_read_rows(png_ptr, png_bytepp_NULL, &row_pointers[y],
- number_of_rows);
+ png_read_rows(png_ptr, NULL, &row_pointers[y],
+ number_of_rows);
#endif no_sparkle /* Use only one of these two methods */
}
- /* If you want to display the image after every pass, do so here */
+ /* If you want to display the image after every pass, do so here. */
#endif no_single /* Use only one of these two methods */
}
#endif no_entire /* Use only one of these two methods */
- /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */
+ /* Read rest of file, and get additional chunks in info_ptr. REQUIRED. */
png_read_end(png_ptr, info_ptr);
#endif hilevel
- /* At this point you have read the entire image */
+ /* At this point you have read the entire image. */
- /* Clean up after the read, and free any memory allocated - REQUIRED */
- png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+ /* Clean up after the read, and free any memory allocated. REQUIRED. */
+ png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
- /* Close the file */
+ /* Close the file. */
fclose(fp);
- /* That's it */
+ /* That's it! */
return (OK);
}
@@ -409,34 +595,30 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
/* Create and initialize the png_struct with the desired error handler
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also check that
- * the library version is compatible in case we are using dynamically
+ * the library version is compatible, in case we are using dynamically
* linked libraries.
*/
*png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
-
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
if (*png_ptr == NULL)
{
*info_ptr = NULL;
return (ERROR);
}
-
*info_ptr = png_create_info_struct(png_ptr);
-
if (*info_ptr == NULL)
{
- png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ png_destroy_read_struct(png_ptr, info_ptr, NULL);
return (ERROR);
}
-
if (setjmp(png_jmpbuf((*png_ptr))))
{
- png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ png_destroy_read_struct(png_ptr, info_ptr, NULL);
return (ERROR);
}
- /* This one's new. You will need to provide all three
- * function callbacks, even if you aren't using them all.
+ /* You will need to provide all three function callbacks,
+ * even if you aren't using all of them.
* If you aren't using all functions, you can specify NULL
* parameters. Even when all three functions are NULL,
* you need to call png_set_progressive_read_fn().
@@ -448,29 +630,28 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
* the function png_get_progressive_ptr(png_ptr).
*/
png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
- info_callback, row_callback, end_callback);
-
+ info_callback, row_callback, end_callback);
return (OK);
}
int
process_data(png_structp *png_ptr, png_infop *info_ptr,
- png_bytep buffer, png_uint_32 length)
+ png_bytep buffer, png_uint_32 length)
{
if (setjmp(png_jmpbuf((*png_ptr))))
{
- /* Free the png_ptr and info_ptr memory on error */
- png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+ /* Free the png_ptr and info_ptr memory on error. */
+ png_destroy_read_struct(png_ptr, info_ptr, NULL);
return (ERROR);
}
- /* This one's new also. Simply give it chunks of data as
- * they arrive from the data stream (in order, of course).
+ /* Give chunks of data as they arrive from the data stream
+ * (in order, of course).
* On segmented machines, don't give it any more than 64K.
* The library seems to run fine with sizes of 4K, although
- * you can give it much less if necessary (I assume you can
+ * you can give it much less if necessary. (I assume you can
* give it chunks of 1 byte, but I haven't tried with less
- * than 256 bytes yet). When this function returns, you may
+ * than 256 bytes yet.) When this function returns, you may
* want to display any rows that were generated in the row
* callback, if you aren't already displaying them there.
*/
@@ -490,10 +671,9 @@ info_callback(png_structp png_ptr, png_infop info)
}
row_callback(png_structp png_ptr, png_bytep new_row,
- png_uint_32 row_num, int pass)
+ png_uint_32 row_num, int pass)
{
- /*
- * This function is called for every row in the image. If the
+ /* This function is called for every row in the image. If the
* image is interlaced, and you turned on the interlace handler,
* this function will be called for every row in every pass.
*
@@ -504,24 +684,22 @@ row_callback(png_structp png_ptr, png_bytep new_row,
* The new row data pointer "new_row" may be NULL, indicating there is
* no new data to be replaced (in cases of interlace loading).
*
- * If new_row is not NULL then you need to call
- * png_progressive_combine_row() to replace the corresponding row as
+ * If new_row is not NULL, then you need to call
+ * png_progressive_combine_row(), to replace the corresponding row as
* shown below:
*/
- /* Get pointer to corresponding row in our
- * PNG read buffer.
- */
+ /* Get pointer to corresponding row in our PNG read buffer. */
png_bytep old_row = ((png_bytep *)our_data)[row_num];
- /* If both rows are allocated then copy the new row
+#ifdef PNG_READ_INTERLACING_SUPPORTED
+ /* If both rows are allocated, then copy the new row
* data to the corresponding row data.
*/
- if ((old_row != NULL) && (new_row != NULL))
- png_progressive_combine_row(png_ptr, old_row, new_row);
+ if (old_row != NULL && new_row != NULL)
+ png_progressive_combine_row(png_ptr, old_row, new_row);
- /*
- * The rows and passes are called in order, so you don't really
+ /* The rows and passes are called in order, so you don't really
* need the row_num and pass, but I'm supplying them because it
* may make your life easier.
*
@@ -529,10 +707,9 @@ row_callback(png_structp png_ptr, png_bytep new_row,
* png_progressive_combine_row() passing in the new row and the
* old row, as demonstrated above. You can call this function for
* NULL rows (it will just return) and for non-interlaced images
- * (it just does the png_memcpy for you) if it will make the code
+ * (it just does the memcpy for you) if it will make the code
* easier. Thus, you can just do this for all cases:
*/
-
png_progressive_combine_row(png_ptr, old_row, new_row);
/* where old_row is what was displayed for previous rows. Note
@@ -542,6 +719,7 @@ row_callback(png_structp png_ptr, png_bytep new_row,
* to pass the current row as new_row, and the function will combine
* the old row and the new row.
*/
+#endif /* READ_INTERLACING */
}
end_callback(png_structp png_ptr, png_infop info)
@@ -577,47 +755,46 @@ void write_png(char *file_name /* , ... other image information ... */)
* in case we are using dynamically linked libraries. REQUIRED.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
- png_voidp user_error_ptr, user_error_fn, user_warning_fn);
-
+ png_voidp user_error_ptr, user_error_fn, user_warning_fn);
if (png_ptr == NULL)
{
fclose(fp);
return (ERROR);
}
- /* Allocate/initialize the image information data. REQUIRED */
+ /* Allocate/initialize the image information data. REQUIRED. */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL)
{
fclose(fp);
- png_destroy_write_struct(&png_ptr, png_infopp_NULL);
+ png_destroy_write_struct(&png_ptr, NULL);
return (ERROR);
}
- /* Set error handling. REQUIRED if you aren't supplying your own
+ /* Set up error handling. REQUIRED if you aren't supplying your own
* error handling functions in the png_create_write_struct() call.
*/
if (setjmp(png_jmpbuf(png_ptr)))
{
- /* If we get here, we had a problem writing the file */
+ /* If we get here, we had a problem writing the file. */
fclose(fp);
png_destroy_write_struct(&png_ptr, &info_ptr);
return (ERROR);
}
- /* One of the following I/O initialization functions is REQUIRED */
+ /* One of the following I/O initialization functions is REQUIRED. */
#ifdef streams /* I/O initialization method 1 */
- /* Set up the output control if you are using standard C streams */
+ /* Set up the output control if you are using standard C streams. */
png_init_io(png_ptr, fp);
#else no_streams /* I/O initialization method 2 */
/* If you are using replacement write functions, instead of calling
- * png_init_io() here you would call
+ * png_init_io(), you would call:
*/
png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
- user_IO_flush_function);
- /* where user_io_ptr is a structure you want available to the callbacks */
+ user_IO_flush_function);
+ /* where user_io_ptr is a structure you want available to the callbacks. */
#endif no_streams /* Only use one initialization method */
#ifdef hilevel
@@ -625,75 +802,97 @@ void write_png(char *file_name /* , ... other image information ... */)
* image info living in the structure. You could "|" many
* PNG_TRANSFORM flags into the png_transforms integer here.
*/
- png_write_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+ png_write_png(png_ptr, info_ptr, png_transforms, NULL);
#else
- /* This is the hard way */
+ /* This is the hard way. */
/* Set the image information here. Width and height are up to 2^31,
- * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
- * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
+ * bit_depth is one of 1, 2, 4, 8 or 16, but valid values also depend on
+ * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
* PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB,
* or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
* PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST
- * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED
+ * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE.
+ * REQUIRED.
*/
- png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???,
- PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+ png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
+ PNG_COLOR_TYPE_???, PNG_INTERLACE_????,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
- /* Set the palette if there is one. REQUIRED for indexed-color images */
- palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
- * png_sizeof(png_color));
+ /* Set the palette if there is one. REQUIRED for indexed-color images. */
+ palette = (png_colorp)png_malloc(png_ptr,
+ PNG_MAX_PALETTE_LENGTH * (sizeof (png_color)));
/* ... Set palette colors ... */
png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
- /* You must not free palette here, because png_set_PLTE only makes a link to
- * the palette that you malloced. Wait until you are about to destroy
+ /* You must not free palette here, because png_set_PLTE only makes a link
+ * to the palette that you allocated. Wait until you are about to destroy
* the png structure.
*/
- /* Optional significant bit (sBIT) chunk */
+ /* Optional significant bit (sBIT) chunk. */
png_color_8 sig_bit;
+
/* If we are dealing with a grayscale image then */
sig_bit.gray = true_bit_depth;
+
/* Otherwise, if we are dealing with a color image then */
sig_bit.red = true_red_bit_depth;
sig_bit.green = true_green_bit_depth;
sig_bit.blue = true_blue_bit_depth;
+
/* If the image has an alpha channel then */
sig_bit.alpha = true_alpha_bit_depth;
- png_set_sBIT(png_ptr, info_ptr, &sig_bit);
+ png_set_sBIT(png_ptr, info_ptr, &sig_bit);
/* Optional gamma chunk is strongly suggested if you have any guess
* as to the correct gamma of the image.
*/
png_set_gAMA(png_ptr, info_ptr, gamma);
- /* Optionally write comments into the image */
- text_ptr[0].key = "Title";
- text_ptr[0].text = "Mona Lisa";
- text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[1].key = "Author";
- text_ptr[1].text = "Leonardo DaVinci";
- text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
- text_ptr[2].key = "Description";
- text_ptr[2].text = "<long text>";
- text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
-#ifdef PNG_iTXt_SUPPORTED
- text_ptr[0].lang = NULL;
- text_ptr[1].lang = NULL;
- text_ptr[2].lang = NULL;
-#endif
- png_set_text(png_ptr, info_ptr, text_ptr, 3);
+ /* Optionally write comments into the image. */
+ {
+ png_text text_ptr[3];
+
+ char key0[] = "Title";
+ char text0[] = "Mona Lisa";
+ text_ptr[0].key = key0;
+ text_ptr[0].text = text0;
+ text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[0].itxt_length = 0;
+ text_ptr[0].lang = NULL;
+ text_ptr[0].lang_key = NULL;
+
+ char key1[] = "Author";
+ char text1[] = "Leonardo DaVinci";
+ text_ptr[1].key = key1;
+ text_ptr[1].text = text1;
+ text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr[1].itxt_length = 0;
+ text_ptr[1].lang = NULL;
+ text_ptr[1].lang_key = NULL;
+
+ char key2[] = "Description";
+ char text2[] = "<long text>";
+ text_ptr[2].key = key2;
+ text_ptr[2].text = text2;
+ text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+ text_ptr[2].itxt_length = 0;
+ text_ptr[2].lang = NULL;
+ text_ptr[2].lang_key = NULL;
+
+ png_set_text(write_ptr, write_info_ptr, text_ptr, 3);
+ }
- /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs */
+ /* Other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs. */
- /* Note that if sRGB is present the gAMA and cHRM chunks must be ignored
+ /* Note that if sRGB is present, the gAMA and cHRM chunks must be ignored
* on read and, if your application chooses to write them, they must
- * be written in accordance with the sRGB profile
+ * be written in accordance with the sRGB profile.
*/
- /* Write the file header information. REQUIRED */
+ /* Write the file header information. REQUIRED. */
png_write_info(png_ptr, info_ptr);
/* If you want, you can write the info in two steps, in case you need to
@@ -708,7 +907,7 @@ void write_png(char *file_name /* , ... other image information ... */)
*/
/* Once we write out the header, the compression type on the text
- * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
+ * chunk gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
* PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
* at the end.
*/
@@ -717,7 +916,7 @@ void write_png(char *file_name /* , ... other image information ... */)
* all optional. Only call them if you want them.
*/
- /* Invert monochrome pixels */
+ /* Invert monochrome pixels. */
png_set_invert_mono(png_ptr);
/* Shift the pixels up to a legal bit depth and fill in
@@ -725,28 +924,28 @@ void write_png(char *file_name /* , ... other image information ... */)
*/
png_set_shift(png_ptr, &sig_bit);
- /* Pack pixels into bytes */
+ /* Pack pixels into bytes. */
png_set_packing(png_ptr);
- /* Swap location of alpha bytes from ARGB to RGBA */
+ /* Swap location of alpha bytes from ARGB to RGBA. */
png_set_swap_alpha(png_ptr);
/* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
- * RGB (4 channels -> 3 channels). The second parameter is not used.
+ * RGB (4 channels -> 3 channels). The second parameter is not used.
*/
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
- /* Flip BGR pixels to RGB */
+ /* Flip BGR pixels to RGB. */
png_set_bgr(png_ptr);
- /* Swap bytes of 16-bit files to most significant byte first */
+ /* Swap bytes of 16-bit files to most significant byte first. */
png_set_swap(png_ptr);
- /* Swap bits of 1, 2, 4 bit packed pixel formats */
+ /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats. */
png_set_packswap(png_ptr);
- /* Turn on interlace handling if you are not using png_write_image() */
- if (interlacing)
+ /* Turn on interlace handling if you are not using png_write_image(). */
+ if (interlacing != 0)
number_passes = png_set_interlace_handling(png_ptr);
else
number_passes = 1;
@@ -756,21 +955,29 @@ void write_png(char *file_name /* , ... other image information ... */)
* use the first method if you aren't handling interlacing yourself.
*/
png_uint_32 k, height, width;
- png_byte image[height][width*bytes_per_pixel];
+
+ /* In this example, "image" is a one-dimensional array of bytes. */
+
+ /* Guard against integer overflow. */
+ if (height > PNG_SIZE_MAX / (width * bytes_per_pixel))
+ png_error(png_ptr, "Image data buffer would be too large");
+
+ png_byte image[height * width * bytes_per_pixel];
png_bytep row_pointers[height];
- if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
- png_error (png_ptr, "Image is too tall to process in memory");
+ if (height > PNG_UINT_32_MAX / (sizeof (png_bytep)))
+ png_error(png_ptr, "Image is too tall to process in memory");
+ /* Set up pointers into your "image" byte array. */
for (k = 0; k < height; k++)
- row_pointers[k] = image + k*width*bytes_per_pixel;
+ row_pointers[k] = image + k * width * bytes_per_pixel;
- /* One of the following output methods is REQUIRED */
+ /* One of the following output methods is REQUIRED. */
#ifdef entire /* Write out the entire image data in one call */
png_write_image(png_ptr, row_pointers);
- /* The other way to write the image - deal with interlacing */
+ /* The other way to write the image - deal with interlacing. */
#else no_entire /* Write out the image data by one or more scanlines */
@@ -782,27 +989,27 @@ void write_png(char *file_name /* , ... other image information ... */)
/* Write a few rows at a time. */
png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows);
- /* If you are only writing one row at a time, this works */
+ /* If you are only writing one row at a time, this works. */
for (y = 0; y < height; y++)
png_write_rows(png_ptr, &row_pointers[y], 1);
}
#endif no_entire /* Use only one output method */
/* You can write optional chunks like tEXt, zTXt, and tIME at the end
- * as well. Shouldn't be necessary in 1.2.0 and up as all the public
- * chunks are supported and you can use png_set_unknown_chunks() to
+ * as well. Shouldn't be necessary in 1.2.0 and up, as all the public
+ * chunks are supported, and you can use png_set_unknown_chunks() to
* register unknown chunks into the info structure to be written out.
*/
- /* It is REQUIRED to call this to finish writing the rest of the file */
+ /* It is REQUIRED to call this to finish writing the rest of the file. */
png_write_end(png_ptr, info_ptr);
#endif hilevel
- /* If you png_malloced a palette, free it here (don't free info_ptr->palette,
- * as recommended in versions 1.0.5m and earlier of this example; if
- * libpng mallocs info_ptr->palette, libpng will free it). If you
- * allocated it with malloc() instead of png_malloc(), use free() instead
- * of png_free().
+ /* If you png_malloced a palette, free it here.
+ * (Don't free info_ptr->palette, as shown in versions 1.0.5m and earlier of
+ * this example; if libpng mallocs info_ptr->palette, libpng will free it).
+ * If you allocated it with malloc() instead of png_malloc(), use free()
+ * instead of png_free().
*/
png_free(png_ptr, palette);
palette = NULL;
@@ -813,19 +1020,20 @@ void write_png(char *file_name /* , ... other image information ... */)
*/
png_free(png_ptr, trans);
trans = NULL;
- /* Whenever you use png_free() it is a good idea to set the pointer to
+
+ /* Whenever you use png_free(), it is a good idea to set the pointer to
* NULL in case your application inadvertently tries to png_free() it
- * again. When png_free() sees a NULL it returns without action, thus
- * avoiding the double-free security problem.
+ * again. When png_free() sees a NULL it returns without action, avoiding
+ * the double-free problem.
*/
- /* Clean up after the write, and free any memory allocated */
+ /* Clean up after the write, and free any allocated memory. */
png_destroy_write_struct(&png_ptr, &info_ptr);
- /* Close the file */
+ /* Close the file. */
fclose(fp);
- /* That's it */
+ /* That's it! */
return (OK);
}
diff --git a/com32/lib/libpng/libpng.3 b/com32/lib/libpng/libpng.3
index 93139a7f..9757debc 100644
--- a/com32/lib/libpng/libpng.3
+++ b/com32/lib/libpng/libpng.3
@@ -1,814 +1,511 @@
-.TH LIBPNG 3 "June 26, 2010"
+.TH LIBPNG 3 "December 1, 2018"
.SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.2.44
-.SH SYNOPSIS
-\fI\fB
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.36
+.SH SYNOPSIS
\fB#include <png.h>\fP
-\fI\fB
+\fBpng_uint_32 png_access_version_number (void);\fP
-\fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP
+\fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
-\fI\fB
+\fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP
-\fBint png_check_sig (png_bytep \fP\fIsig\fP\fB, int \fInum\fP\fB);\fP
+\fBpng_voidp png_calloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
-\fI\fB
+\fBvoid png_chunk_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
\fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
-\fI\fB
-
\fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
-\fI\fB
-
\fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP
-\fI\fB
-
\fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP
-\fI\fB
-
\fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP
-\fI\fB
-
\fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
-\fI\fB
-
-\fBpng_structp png_create_read_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
-
-\fI\fB
+\fBpng_structp png_create_read_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
\fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP
-\fI\fB
-
-\fBpng_structp png_create_write_struct_2(png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
-
-\fI\fB
+\fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
-\fBint png_debug(int \fP\fIlevel\fP\fB, png_const_charp \fImessage\fP\fB);\fP
-
-\fI\fB
-
-\fBint png_debug1(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fIp1\fP\fB);\fP
-
-\fI\fB
-
-\fBint png_debug2(int \fP\fIlevel\fP\fB, png_const_charp \fP\fImessage\fP\fB, \fP\fIp1\fP\fB, \fIp2\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask\fP\fB);\fP
\fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_err (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP
-\fI\fB
-
\fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_free_default(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_free_default (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP
\fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP
-\fI\fB
-
-\fBpng_byte png_get_bit_depth (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_byte png_get_bit_depth (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_bKGD (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP
-\fBpng_uint_32 png_get_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP
+\fBpng_byte png_get_channels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_cHRM (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP
-\fBpng_byte png_get_channels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_cHRM_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*red_X\fP\fB, double \fP\fI*red_Y\fP\fB, double \fP\fI*red_Z\fP\fB, double \fP\fI*green_X\fP\fB, double \fP\fI*green_Y\fP\fB, double \fP\fI*green_Z\fP\fB, double \fP\fI*blue_X\fP\fB, double \fP\fI*blue_Y\fP\fB, double \fI*blue_Z\fP\fB);\fP
-\fBpng_uint_32 png_get_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP
+\fBpng_uint_32 png_get_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fI*int_red_X\fP\fB, png_fixed_point \fP\fI*int_red_Y\fP\fB, png_fixed_point \fP\fI*int_red_Z\fP\fB, png_fixed_point \fP\fI*int_green_X\fP\fB, png_fixed_point \fP\fI*int_green_Y\fP\fB, png_fixed_point \fP\fI*int_green_Z\fP\fB, png_fixed_point \fP\fI*int_blue_X\fP\fB, png_fixed_point \fP\fI*int_blue_Y\fP\fB, png_fixed_point \fI*int_blue_Z\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP
+\fBpng_alloc_size_t png_get_chunk_malloc_max (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_byte png_get_color_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_byte png_get_color_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_compression_buffer_size (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_byte png_get_compression_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_byte png_get_compression_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_byte png_get_copyright (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_current_row_number \fI(png_const_structp\fP\fB);\fP
-\fBpng_byte png_get_copyright (png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_byte png_get_current_pass_number \fI(png_const_structp\fP\fB);\fP
-\fI\fB
+\fBpng_voidp png_get_error_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_voidp png_get_error_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_byte png_get_filter_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_gAMA (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP
-\fBpng_byte png_get_filter_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_gAMA_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP
-\fI\fB
+\fBpng_byte png_get_header_ver (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP
+\fBpng_byte png_get_header_version (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_eXIf (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fI*exif\fP\fB);\fP
-\fBpng_uint_32 png_get_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP
+\fBpng_uint_32 png_get_eXIf_1 (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_unit_32 \fP\fI*num_exif\fP\fB, png_bytep \fI*exif\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_hIST (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP
-\fBpng_byte png_get_header_ver (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_byte png_get_header_version (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_charpp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP
-
-\fI\fB
+\fBpng_uint_32 png_get_iCCP (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_bytepp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP
\fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP
-\fI\fB
-
-\fBpng_uint_32 png_get_image_height (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-
-\fI\fB
+\fBpng_uint_32 png_get_image_height (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_image_width (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fB#if \fI!defined(PNG_1_0_X)
+\fBpng_uint_32 png_get_image_width (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP
-\fI\fB#endif
-
-\fI\fB
+\fBpng_byte png_get_interlace_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_byte png_get_interlace_type (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-
-\fI\fB
+\fBpng_uint_32 png_get_io_chunk_type (png_const_structp \fIpng_ptr\fP\fB);\fP
\fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
-\fBpng_byte png_get_libpng_ver (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_voidp png_get_mem_ptr(png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
-
-\fI\fB
-
-\fBfloat png_get_pixel_aspect_ratio (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_io_state (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_byte png_get_libpng_ver (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBint png_get_palette_max(png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_voidp png_get_mem_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_voidp png_get_progressive_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_oFFs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_pCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP
-\fBpng_uint_32 png_get_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP
+\fBpng_uint_32 png_get_pHYs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
-\fI\fB
+\fBfloat png_get_pixel_aspect_ratio (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_byte png_get_rgb_to_gray_status (png_structp \fIpng_ptr)
+\fBpng_uint_32 png_get_pHYs_dpi (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP
-\fBpng_uint_32 png_get_rowbytes (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_fixed_point png_get_pixel_aspect_ratio_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_bytepp png_get_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_voidp png_get_progressive_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP
+\fBpng_uint_32 png_get_PLTE (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP
-\fI\fB
+\fBpng_byte png_get_rgb_to_gray_status (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_bytep png_get_signature (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_rowbytes (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_bytepp png_get_rows (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_sBIT (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP
-\fI\fB
+\fBvoid png_get_sCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, double* \fP\fIwidth\fP\fB, double* \fIheight\fP\fB);\fP
-\fBpng_uint_32 png_get_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fI*intent\fP\fB);\fP
+\fBvoid png_get_sCAL_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_fixed_pointp \fP\fIwidth\fP\fB, png_fixed_pointp \fIheight\fP\fB);\fP
-\fI\fB
+\fBvoid png_get_sCAL_s (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_charpp \fP\fIwidth\fP\fB, png_charpp \fIheight\fP\fB);\fP
-\fBpng_uint_32 png_get_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP
+\fBpng_bytep png_get_signature (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_sPLT (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP
+\fBpng_uint_32 png_get_sRGB (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int \fI*file_srgb_intent\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_text (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP
-\fBpng_uint_32 png_get_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_values\fP\fB);\fP
+\fBpng_uint_32 png_get_tIME (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_tRNS (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans_alpha\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_color\fP\fB);\fP
-\fB#if \fI!defined(PNG_1_0_X)
+\fB/* This function is really an inline macro. \fI*/
\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_uint_31 (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIbuf\fP\fB);\fP
-\fBpng_uint_32 png_get_uint_31 (png_bytep \fIbuf\fP\fB);\fP
-
-\fI\fB
+\fB/* This function is really an inline macro. \fI*/
\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP
-\fI\fB#endif
-
-\fI\fB
-
-\fBpng_uint_32 png_get_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_voidp png_get_user_chunk_ptr (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
+\fBpng_uint_32 png_get_unknown_chunks (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP
-\fBpng_uint_32 png_get_user_height_max( png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_voidp png_get_user_chunk_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_user_height_max (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_voidp png_get_user_transform_ptr (png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_voidp png_get_user_transform_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_user_width_max (png_const_structp \fIpng_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_user_width_max (png_structp \fIpng_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_valid (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP
-\fI\fB
+\fBfloat png_get_x_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_valid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP
+\fBpng_fixed_point png_get_x_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_int_32 png_get_x_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_int_32 png_get_x_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_int_32 png_get_x_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_x_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_int_32 png_get_x_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_uint_32 png_get_x_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBfloat png_get_y_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_uint_32 png_get_x_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_fixed_point png_get_y_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_int_32 png_get_y_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_int_32 png_get_y_offset_microns (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+\fBpng_int_32 png_get_y_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_get_y_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
-\fBpng_int_32 png_get_y_offset_pixels (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_y_pixels_per_meter (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBpng_uint_32 png_get_compression_buffer_size (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
+\fBpng_uint_32 png_get_y_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP
\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP
-
-\fI\fB
-
-\fBDEPRECATED: void png_info_init (png_infop \fIinfo_ptr\fP\fB);\fP
+\fBint png_image_begin_read_from_file (png_imagep \fP\fIimage\fP\fB, const char \fI*file_name\fP\fB);\fP
-\fI\fB
+\fBint png_image_begin_read_from_stdio (png_imagep \fP\fIimage\fP\fB, FILE* \fIfile\fP\fB);\fP
-\fBDEPRECATED: void png_info_init_2 (png_infopp \fP\fIptr_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP
+\fBint, png_image_begin_read_from_memory (png_imagep \fP\fIimage\fP\fB, png_const_voidp \fP\fImemory\fP\fB, size_t \fIsize\fP\fB);\fP
-\fI\fB
+\fBint png_image_finish_read (png_imagep \fP\fIimage\fP\fB, png_colorp \fP\fIbackground\fP\fB, void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP
-\fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+\fBvoid png_image_free (png_imagep \fIimage\fP\fB);\fP
-\fI\fB
+\fBint png_image_write_to_file (png_imagep \fP\fIimage\fP\fB, const char \fP\fI*file\fP\fB, int \fP\fIconvert_to_8bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP
-\fBpng_voidp png_malloc_default(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+\fBint png_image_write_to_memory (png_imagep \fP\fIimage\fP\fB, void \fP\fI*memory\fP\fB, png_alloc_size_t * PNG_RESTRICT \fP\fImemory_bytes\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, const void \fI*colormap\fP\fB);\fP
-\fI\fB
+\fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fP\fIrow_stride\fP\fB, void \fI*colormap\fP\fB);\fP
-\fBvoidp png_memcpy (png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_size_t \fIsize\fP\fB);\fP
+\fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, size_t \fIpng_info_struct_size\fP\fB);\fP
-\fI\fB
-
-\fBpng_voidp png_memcpy_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, png_voidp \fP\fIs2\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP
-\fBvoidp png_memset (png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_size_t \fIsize\fP\fB);\fP
+\fBvoid png_longjmp (png_structp \fP\fIpng_ptr\fP\fB, int \fIval\fP\fB);\fP
-\fI\fB
+\fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
-\fBpng_voidp png_memset_check (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIs1\fP\fB, int \fP\fIvalue\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
+\fBpng_voidp png_malloc_default (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
-\fI\fB
+\fBpng_voidp png_malloc_warn (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP
-\fBDEPRECATED: void png_permit_empty_plte (png_structp \fP\fIpng_ptr\fP\fB, int \fIempty_plte_permitted\fP\fB);\fP
+\fBpng_uint_32 png_permit_mng_features (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fImng_features_permitted\fP\fB);\fP
-\fI\fB
+\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, size_t \fIbuffer_size\fP\fB);\fP
-\fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP
+\fBsize_t png_process_data_pause (png_structp \fP\fIpng_ptr\fP\fB, int \fIsave\fP\fB);\fP
-\fI\fB
+\fBpng_uint_32 png_process_data_skip (png_structp \fP\fIpng_ptr\fP\fB);\fP
\fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_read_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_infop \fIend_info_ptr\fP\fB);\fP
-
-\fI\fB
-
\fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
-\fI\fB
-
-\fBDEPRECATED: void png_read_init (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBDEPRECATED: void png_read_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
-
-\fI\fB
-
\fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
-\fI\fB
-
\fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP
-\fI\fB
-
\fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
-\fI\fB
-
\fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
-\fB#if \fI!defined(PNG_1_0_X)
-
-\fBpng_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+\fBint png_reset_zstream (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
-\fI\fB
-
\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
-\fI\fB#endif
+\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP
\fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_background_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, png_uint_32 \fIbackground_gamma\fP\fB);\fP
-\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
+\fBvoid png_set_benign_errors (png_structp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_check_for_invalid_index (png_structrp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP
\fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIred_X\fP\fB, double \fP\fIred_Y\fP\fB, double \fP\fIred_Z\fP\fB, double \fP\fIgreen_X\fP\fB, double \fP\fIgreen_Y\fP\fB, double \fP\fIgreen_Z\fP\fB, double \fP\fIblue_X\fP\fB, double \fP\fIblue_Y\fP\fB, double \fIblue_Z\fP\fB);\fP
-\fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
+\fBvoid png_set_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fIint_red_X\fP\fB, png_fixed_point \fP\fIint_red_Y\fP\fB, png_fixed_point \fP\fIint_red_Z\fP\fB, png_fixed_point \fP\fIint_green_X\fP\fB, png_fixed_point \fP\fIint_green_Y\fP\fB, png_fixed_point \fP\fIint_green_Z\fP\fB, png_fixed_point \fP\fIint_blue_X\fP\fB, png_fixed_point \fP\fIint_blue_Y\fP\fB, png_fixed_point \fIint_blue_Z\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_chunk_cache_max (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIuser_chunk_cache_max\fP\fB);\fP
-\fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
+\fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
\fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_dither (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_dither\fP\fB);\fP
-
-\fI\fB
-
\fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_expand_gray_1_2_4_to_8(png_structp \fIpng_ptr\fP\fB);\fP
+\fBvoid png_set_expand_16 (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_filter_heuristics_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_fixed_point_p \fP\fIfilter_weights\fP\fB, png_fixed_point_p \fIfilter_costs\fP\fB);\fP
\fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_gamma_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIscreen_gamma\fP\fB, png_uint_32 \fIdefault_file_gamma\fP\fB);\fP
\fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_gray_1_2_4_to_8(png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_eXIf (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fIexif\fP\fB);\fP
-\fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_eXIf_1 (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fInum_exif\fP\fB, png_bytep \fIexif\fP\fB);\fP
-\fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP
+\fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_const_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_const_bytep \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP
\fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP
-\fI\fB
+\fBjmp_buf* png_set_longjmp_fn (png_structp \fP\fIpng_ptr\fP\fB, png_longjmp_ptr \fP\fIlongjmp_fn\fP\fB, size_t \fIjmp_buf_size\fP\fB);\fP
+
+\fBvoid png_set_chunk_malloc_max (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIuser_chunk_cache_max\fP\fB);\fP
-\fBvoid png_set_mem_fn(png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
+\fBvoid png_set_compression_buffer_size (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_mem_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
\fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP
-\fI\fB
+\fBint png_set_option(png_structrp \fP\fIpng_ptr\fP\fB, int \fP\fIoption\fP\fB, int \fIonoff\fP\fB);\fP
\fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_palette_to_rgb(png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_palette_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP
\fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_quantize (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_quantize\fP\fB);\fP
\fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP
\fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_fixed_point \fP\fIred\fP\fB, png_fixed_point \fIgreen\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_uint_32 \fP\fIred\fP\fB, png_uint_32 \fIgreen\fP\fB);\fP
\fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
-\fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
+\fBvoid png_set_sCAL_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_fixed_point \fP\fIwidth\fP\fB, png_fixed_point \fIheight\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP
-\fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
+\fBvoid png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP
\fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
-
-\fI\fB
-
-\fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIintent\fP\fB);\fP
+\fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP
\fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_strip_error_numbers (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIstrip_mode\fP\fB);\fP
\fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_text_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP
-\fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_values\fP\fB);\fP
+\fBvoid png_set_text_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_text_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP
-\fBvoid png_set_tRNS_to_alpha(png_structp \fIpng_ptr\fP\fB);\fP
+\fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_text_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP
-\fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
-\fBvoid png_set_unknown_chunk_location(png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP
+\fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans_alpha\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_color\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_tRNS_to_alpha (png_structp \fIpng_ptr\fP\fB);\fP
-\fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP
+\fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP
-\fI\fB
+\fBvoid png_set_unknown_chunk_location (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP
\fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP
-\fI\fB
-
\fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_set_compression_buffer_size(png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP
-
-\fI\fB
-
-\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP
-
-\fI\fB
+\fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, size_t \fP\fIstart\fP\fB, size_t \fInum_to_check\fP\fB);\fP
\fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+\fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, size_t \fIlength\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, size_t \fIlength\fP\fB);\fP
\fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
-\fI\fB
-
-\fBvoid png_write_destroy (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
\fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP
-\fI\fB
-
-\fBDEPRECATED: void png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
-
-\fI\fB
-
-\fBDEPRECATED: void png_write_init_2 (png_structpp \fP\fIptr_ptr\fP\fB, png_const_charp \fP\fIuser_png_ver\fP\fB, png_size_t \fP\fIpng_struct_size\fP\fB, png_size_t \fIpng_info_size\fP\fB);\fP
-
-\fI\fB
-
\fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
-\fI\fB
-
\fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP
-\fI\fB
-
-\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
-
-\fI\fB
-
-\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
-
-\fI\fB
+\fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
.SH DESCRIPTION
The
@@ -817,14 +514,13 @@ library supports encoding, decoding, and various manipulations of
the Portable Network Graphics (PNG) format image files. It uses the
.IR zlib(3)
compression library.
-Following is a copy of the libpng.txt file that accompanies libpng.
+Following is a copy of the libpng-manual.txt file that accompanies libpng.
+
.SH LIBPNG.TXT
-libpng.txt - A description on how to use and modify libpng
+libpng-manual.txt - A description on how to use and modify libpng
- libpng version 1.2.44 - June 26, 2010
- Updated and distributed by Glenn Randers-Pehrson
- <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ Copyright (c) 2018 Cosmin Truta
+ Copyright (c) 1998-2018 Glenn Randers-Pehrson
This document is released under the libpng license.
For conditions of distribution and use, see the disclaimer
@@ -832,15 +528,19 @@ libpng.txt - A description on how to use and modify libpng
Based on:
- libpng versions 0.97, January 1998, through 1.2.44 - June 26, 2010
+ libpng version 1.6.36 - December 1, 2018
+ Updated and distributed by Cosmin Truta
+ Copyright (c) 2018 Cosmin Truta
+
+ libpng versions 0.97, January 1998, through 1.6.35 - July 15, 2018
Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2009 Glenn Randers-Pehrson
+ Copyright (c) 1998-2018 Glenn Randers-Pehrson
- libpng 1.0 beta 6 version 0.96 May 28, 1997
+ libpng 1.0 beta 6 - version 0.96 - May 28, 1997
Updated and distributed by Andreas Dilger
Copyright (c) 1996, 1997 Andreas Dilger
- libpng 1.0 beta 2 - version 0.88 January 26, 1996
+ libpng 1.0 beta 2 - version 0.88 - January 26, 1996
For conditions of distribution and use, see copyright
notice in png.h. Copyright (c) 1995, 1996 Guy Eric
Schalnat, Group 42, Inc.
@@ -849,16 +549,32 @@ libpng.txt - A description on how to use and modify libpng
Copyright (c) 1995, 1996 Frank J. T. Wojcik
December 18, 1995 & January 20, 1996
+ TABLE OF CONTENTS
+
+ I. Introduction
+ II. Structures
+ III. Reading
+ IV. Writing
+ V. Simplified API
+ VI. Modifying/Customizing libpng
+ VII. MNG support
+ VIII. Changes to Libpng from version 0.88
+ IX. Changes to Libpng from version 1.0.x to 1.2.x
+ X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+ XI. Changes to Libpng from version 1.4.x to 1.5.x
+ XII. Changes to Libpng from version 1.5.x to 1.6.x
+ XIII. Detecting libpng
+ XIV. Source code repository
+ XV. Coding style
+
.SH I. Introduction
This file describes how to use and modify the PNG reference library
-(known as libpng) for your own use. There are five sections to this
-file: introduction, structures, reading, writing, and modification and
-configuration notes for various special platforms. In addition to this
+(known as libpng) for your own use. In addition to this
file, example.c is a good starting point for using the library, as
it is heavily commented and should include everything most people
will need. We assume that libpng is already installed; see the
-INSTALL file for instructions on how to install libpng.
+INSTALL file for instructions on how to configure and install libpng.
For examples of libpng usage, see the files "example.c", "pngtest.c",
and the files in the "contrib" directory, all of which are included in
@@ -869,20 +585,21 @@ of reducing the amount of time and effort it takes to support the PNG
file format in application programs.
The PNG specification (second edition), November 2003, is available as
-a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2003 (E)) at
-<http://www.w3.org/TR/2003/REC-PNG-20031110/
+a W3C Recommendation and as an ISO Standard (ISO/IEC 15948:2004 (E)) at
+<https://www.w3.org/TR/2003/REC-PNG-20031110/>.
The W3C and ISO documents have identical technical content.
The PNG-1.2 specification is available at
-<http://www.libpng.org/pub/png/documents/>. It is technically equivalent
+<https://png-mng.sourceforge.io/pub/png/spec/1.2/>.
+It is technically equivalent
to the PNG specification (second edition) but has some additional material.
-The PNG-1.0 specification is available
-as RFC 2083 <http://www.libpng.org/pub/png/documents/> and as a
-W3C Recommendation <http://www.w3.org/TR/REC.png.html>.
+The PNG-1.0 specification is available as RFC 2083 at
+<https://png-mng.sourceforge.io/pub/png/spec/1.0/> and as a
+W3C Recommendation at <https://www.w3.org/TR/REC-png-961001>.
Some additional chunks are described in the special-purpose public chunks
-documents at <http://www.libpng.org/pub/png/documents/>.
+documents at <http://www.libpng.org/pub/png/spec/register/>
Other information
about PNG, and the latest version of libpng, can be found at the PNG home
@@ -904,7 +621,7 @@ majority of the needs of its users.
Libpng uses zlib for its compression and decompression of PNG files.
Further information about zlib, and the latest version of zlib, can
-be found at the zlib home page, <http://www.info-zip.org/pub/infozip/zlib/>.
+be found at the zlib home page, <https://zlib.net/>.
The zlib compression utility is a general purpose utility that is
useful for more than PNG files, and can be used without libpng.
See the documentation delivered with zlib for more details.
@@ -920,34 +637,203 @@ same instance of a structure.
.SH II. Structures
There are two main structures that are important to libpng, png_struct
-and png_info. The first, png_struct, is an internal structure that
-will not, for the most part, be used by a user except as the first
-variable passed to every libpng function call.
+and png_info. Both are internal structures that are no longer exposed
+in the libpng interface (as of libpng 1.5.0).
The png_info structure is designed to provide information about the
PNG file. At one time, the fields of png_info were intended to be
directly accessible to the user. However, this tended to cause problems
with applications using dynamically loaded libraries, and as a result
a set of interface functions for png_info (the png_get_*() and png_set_*()
-functions) was developed. The fields of png_info are still available for
-older applications, but it is suggested that applications use the new
-interfaces if at all possible.
-
-Applications that do make direct access to the members of png_struct (except
-for png_ptr->jmpbuf) must be recompiled whenever the library is updated,
-and applications that make direct access to the members of png_info must
-be recompiled if they were compiled or loaded with libpng version 1.0.6,
-in which the members were in a different order. In version 1.0.7, the
-members of the png_info structure reverted to the old order, as they were
-in versions 0.97c through 1.0.5. Starting with version 2.0.0, both
-structures are going to be hidden, and the contents of the structures will
-only be accessible through the png_get/png_set functions.
+functions) was developed, and direct access to the png_info fields was
+deprecated..
+
+The png_struct structure is the object used by the library to decode a
+single image. As of 1.5.0 this structure is also not exposed.
+
+Almost all libpng APIs require a pointer to a png_struct as the first argument.
+Many (in particular the png_set and png_get APIs) also require a pointer
+to png_info as the second argument. Some application visible macros
+defined in png.h designed for basic data access (reading and writing
+integers in the PNG format) don't take a png_info pointer, but it's almost
+always safe to assume that a (png_struct*) has to be passed to call an API
+function.
+
+You can have more than one png_info structure associated with an image,
+as illustrated in pngtest.c, one for information valid prior to the
+IDAT chunks and another (called "end_info" below) for things after them.
The png.h header file is an invaluable reference for programming with libpng.
And while I'm on the topic, make sure you include the libpng header file:
#include <png.h>
+and also (as of libpng-1.5.0) the zlib header file, if you need it:
+
+#include <zlib.h>
+
+.SS Types
+
+The png.h header file defines a number of integral types used by the
+APIs. Most of these are fairly obvious; for example types corresponding
+to integers of particular sizes and types for passing color values.
+
+One exception is how non-integral numbers are handled. For application
+convenience most APIs that take such numbers have C (double) arguments;
+however, internally PNG, and libpng, use 32 bit signed integers and encode
+the value by multiplying by 100,000. As of libpng 1.5.0 a convenience
+macro PNG_FP_1 is defined in png.h along with a type (png_fixed_point)
+which is simply (png_int_32).
+
+All APIs that take (double) arguments also have a matching API that
+takes the corresponding fixed point integer arguments. The fixed point
+API has the same name as the floating point one with "_fixed" appended.
+The actual range of values permitted in the APIs is frequently less than
+the full range of (png_fixed_point) (\-21474 to +21474). When APIs require
+a non-negative argument the type is recorded as png_uint_32 above. Consult
+the header file and the text below for more information.
+
+Special care must be take with sCAL chunk handling because the chunk itself
+uses non-integral values encoded as strings containing decimal floating point
+numbers. See the comments in the header file.
+
+.SS Configuration
+
+The main header file function declarations are frequently protected by C
+preprocessing directives of the form:
+
+ #ifdef PNG_feature_SUPPORTED
+ declare-function
+ #endif
+ ...
+ #ifdef PNG_feature_SUPPORTED
+ use-function
+ #endif
+
+The library can be built without support for these APIs, although a
+standard build will have all implemented APIs. Application programs
+should check the feature macros before using an API for maximum
+portability. From libpng 1.5.0 the feature macros set during the build
+of libpng are recorded in the header file "pnglibconf.h" and this file
+is always included by png.h.
+
+If you don't need to change the library configuration from the default, skip to
+the next section ("Reading").
+
+Notice that some of the makefiles in the 'scripts' directory and (in 1.5.0) all
+of the build project files in the 'projects' directory simply copy
+scripts/pnglibconf.h.prebuilt to pnglibconf.h. This means that these build
+systems do not permit easy auto-configuration of the library - they only
+support the default configuration.
+
+The easiest way to make minor changes to the libpng configuration when
+auto-configuration is supported is to add definitions to the command line
+using (typically) CPPFLAGS. For example:
+
+CPPFLAGS=\-DPNG_NO_FLOATING_ARITHMETIC
+
+will change the internal libpng math implementation for gamma correction and
+other arithmetic calculations to fixed point, avoiding the need for fast
+floating point support. The result can be seen in the generated pnglibconf.h -
+make sure it contains the changed feature macro setting.
+
+If you need to make more extensive configuration changes - more than one or two
+feature macro settings - you can either add \-DPNG_USER_CONFIG to the build
+command line and put a list of feature macro settings in pngusr.h or you can set
+DFA_XTRA (a makefile variable) to a file containing the same information in the
+form of 'option' settings.
+
+A. Changing pnglibconf.h
+
+A variety of methods exist to build libpng. Not all of these support
+reconfiguration of pnglibconf.h. To reconfigure pnglibconf.h it must either be
+rebuilt from scripts/pnglibconf.dfa using awk or it must be edited by hand.
+
+Hand editing is achieved by copying scripts/pnglibconf.h.prebuilt to
+pnglibconf.h and changing the lines defining the supported features, paying
+very close attention to the 'option' information in scripts/pnglibconf.dfa
+that describes those features and their requirements. This is easy to get
+wrong.
+
+B. Configuration using DFA_XTRA
+
+Rebuilding from pnglibconf.dfa is easy if a functioning 'awk', or a later
+variant such as 'nawk' or 'gawk', is available. The configure build will
+automatically find an appropriate awk and build pnglibconf.h.
+The scripts/pnglibconf.mak file contains a set of make rules for doing the
+same thing if configure is not used, and many of the makefiles in the scripts
+directory use this approach.
+
+When rebuilding simply write a new file containing changed options and set
+DFA_XTRA to the name of this file. This causes the build to append the new file
+to the end of scripts/pnglibconf.dfa. The pngusr.dfa file should contain lines
+of the following forms:
+
+everything = off
+
+This turns all optional features off. Include it at the start of pngusr.dfa to
+make it easier to build a minimal configuration. You will need to turn at least
+some features on afterward to enable either reading or writing code, or both.
+
+option feature on
+option feature off
+
+Enable or disable a single feature. This will automatically enable other
+features required by a feature that is turned on or disable other features that
+require a feature which is turned off. Conflicting settings will cause an error
+message to be emitted by awk.
+
+setting feature default value
+
+Changes the default value of setting 'feature' to 'value'. There are a small
+number of settings listed at the top of pnglibconf.h, they are documented in the
+source code. Most of these values have performance implications for the library
+but most of them have no visible effect on the API. Some can also be overridden
+from the API.
+
+This method of building a customized pnglibconf.h is illustrated in
+contrib/pngminim/*. See the "$(PNGCONF):" target in the makefile and
+pngusr.dfa in these directories.
+
+C. Configuration using PNG_USER_CONFIG
+
+If \-DPNG_USER_CONFIG is added to the CPPFLAGS when pnglibconf.h is built,
+the file pngusr.h will automatically be included before the options in
+scripts/pnglibconf.dfa are processed. Your pngusr.h file should contain only
+macro definitions turning features on or off or setting settings.
+
+Apart from the global setting "everything = off" all the options listed above
+can be set using macros in pngusr.h:
+
+#define PNG_feature_SUPPORTED
+
+is equivalent to:
+
+option feature on
+
+#define PNG_NO_feature
+
+is equivalent to:
+
+option feature off
+
+#define PNG_feature value
+
+is equivalent to:
+
+setting feature default value
+
+Notice that in both cases, pngusr.dfa and pngusr.h, the contents of the
+pngusr file you supply override the contents of scripts/pnglibconf.dfa
+
+If confusing or incomprehensible behavior results it is possible to
+examine the intermediate file pnglibconf.dfn to find the full set of
+dependency information for each setting and option. Simply locate the
+feature in the file and read the C comments that precede it.
+
+This method is also illustrated in the contrib/pngminim/* makefiles and
+pngusr.h.
+
.SH III. Reading
We'll now walk you through the possible functions to call when reading
@@ -971,7 +857,7 @@ prediction.
If you are intending to keep the file pointer open for use in libpng,
you must ensure you don't read more than 8 bytes from the beginning
-of the file, and you also have to make a call to png_set_sig_bytes_read()
+of the file, and you also have to make a call to png_set_sig_bytes()
with the number of bytes you read from the beginning. Libpng will
then only check the bytes (if any) that your program didn't read.
@@ -979,20 +865,23 @@ then only check the bytes (if any) that your program didn't read.
to replace them with custom functions. See the discussion under
Customizing libpng.
-
FILE *fp = fopen(file_name, "rb");
if (!fp)
{
- return (ERROR);
+ return ERROR;
+ }
+
+ if (fread(header, 1, number, fp) != number)
+ {
+ return ERROR;
}
- fread(header, 1, number, fp);
+
is_png = !png_sig_cmp(header, 0, number);
if (!is_png)
{
- return (NOT_PNG);
+ return NOT_PNG;
}
-
Next, png_struct and png_info need to be allocated and initialized. In
order to ensure that the size of these structures is correct even with a
dynamically linked libpng, there are functions to initialize and
@@ -1005,33 +894,27 @@ The structure allocation functions quietly return NULL if they fail to
create the structure, so your application should check for that.
png_structp png_ptr = png_create_read_struct
- (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
user_error_fn, user_warning_fn);
+
if (!png_ptr)
- return (ERROR);
+ return ERROR;
png_infop info_ptr = png_create_info_struct(png_ptr);
+
if (!info_ptr)
{
- png_destroy_read_struct(&png_ptr,
+ png_destroy_read_struct(&png_ptr,
(png_infopp)NULL, (png_infopp)NULL);
- return (ERROR);
- }
-
- png_infop end_info = png_create_info_struct(png_ptr);
- if (!end_info)
- {
- png_destroy_read_struct(&png_ptr, &info_ptr,
- (png_infopp)NULL);
- return (ERROR);
+ return ERROR;
}
If you want to use your own memory allocation routines,
-define PNG_USER_MEM_SUPPORTED and use
+use a libpng that was built with PNG_USER_MEM_SUPPORTED defined, and use
png_create_read_struct_2() instead of png_create_read_struct():
png_structp png_ptr = png_create_read_struct_2
- (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+ (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
user_error_fn, user_warning_fn, (png_voidp)
user_mem_ptr, user_malloc_fn, user_free_fn);
@@ -1043,7 +926,7 @@ handling and memory alloc/free functions.
When libpng encounters an error, it expects to longjmp back
to your routine. Therefore, you will need to call setjmp and pass
your png_jmpbuf(png_ptr). If you read the file from different
-routines, you will need to update the jmpbuf field every time you enter
+routines, you will need to update the longjmp buffer every time you enter
a new routine that will call a png_*() function.
See your documentation of setjmp/longjmp for your compiler for more
@@ -1055,16 +938,23 @@ free any memory.
if (setjmp(png_jmpbuf(png_ptr)))
{
- png_destroy_read_struct(&png_ptr, &info_ptr,
+ png_destroy_read_struct(&png_ptr, &info_ptr,
&end_info);
- fclose(fp);
- return (ERROR);
+ fclose(fp);
+ return ERROR;
}
+Pass (png_infopp)NULL instead of &end_info if you didn't create
+an end_info structure.
+
If you would rather avoid the complexity of setjmp/longjmp issues,
-you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+you can compile libpng with PNG_NO_SETJMP, in which case
errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+
Now you need to set up the input code. The default for libpng is to
use the C function fread(). If you use this, you will need to pass a
valid FILE * in the function png_init_io(). Be sure that the file is
@@ -1081,12 +971,50 @@ libpng know that there are some bytes missing from the start of the file.
png_set_sig_bytes(png_ptr, number);
+You can change the zlib compression buffer size to be used while
+reading compressed data with
+
+ png_set_compression_buffer_size(png_ptr, buffer_size);
+
+where the default size is 8192 bytes. Note that the buffer size
+is changed immediately and the buffer is reallocated immediately,
+instead of setting a flag to be acted upon later.
+
+If you want CRC errors to be handled in a different manner than
+the default, use
+
+ png_set_crc_action(png_ptr, crit_action, ancil_action);
+
+The values for png_set_crc_action() say how libpng is to handle CRC errors in
+ancillary and critical chunks, and whether to use the data contained
+therein. Starting with libpng-1.6.26, this also governs how an ADLER32 error
+is handled while reading the IDAT chunk. Note that it is impossible to
+"discard" data in a critical chunk.
+
+Choices for (int) crit_action are
+ PNG_CRC_DEFAULT 0 error/quit
+ PNG_CRC_ERROR_QUIT 1 error/quit
+ PNG_CRC_WARN_USE 3 warn/use data
+ PNG_CRC_QUIET_USE 4 quiet/use data
+ PNG_CRC_NO_CHANGE 5 use the current value
+
+Choices for (int) ancil_action are
+ PNG_CRC_DEFAULT 0 error/quit
+ PNG_CRC_ERROR_QUIT 1 error/quit
+ PNG_CRC_WARN_DISCARD 2 warn/discard data
+ PNG_CRC_WARN_USE 3 warn/use data
+ PNG_CRC_QUIET_USE 4 quiet/use data
+ PNG_CRC_NO_CHANGE 5 use the current value
+
+When the setting for crit_action is PNG_CRC_QUIET_USE, the CRC and ADLER32
+checksums are not only ignored, but they are not evaluated.
+
.SS Setting up callback code
You can set up a callback function to handle any unknown chunks in the
input stream. You must supply the function
- read_chunk_callback(png_ptr ptr,
+ read_chunk_callback(png_structp png_ptr,
png_unknown_chunkp chunk);
{
/* The unknown chunk structure contains your
@@ -1095,7 +1023,7 @@ input stream. You must supply the function
png_byte name[5];
png_byte *data;
- png_size_t size;
+ size_t size;
/* Note that libpng has already taken care of
the CRC handling */
@@ -1104,9 +1032,9 @@ input stream. You must supply the function
unknown chunk structure, process it, and return one
of the following: */
- return (-n); /* chunk had an error */
- return (0); /* did not recognize */
- return (n); /* success */
+ return \-n; /* chunk had an error */
+ return 0; /* did not recognize */
+ return n; /* success */
}
(You can give your function another name that you like instead of
@@ -1123,17 +1051,22 @@ you can retrieve with
png_get_user_chunk_ptr(png_ptr);
If you call the png_set_read_user_chunk_fn() function, then all unknown
-chunks will be saved when read, in case your callback function will need
-one or more of them. This behavior can be changed with the
-png_set_keep_unknown_chunks() function, described below.
+chunks which the callback does not handle will be saved when read. You can
+cause them to be discarded by returning '1' ("handled") instead of '0'. This
+behavior will change in libpng 1.7 and the default handling set by the
+png_set_keep_unknown_chunks() function, described below, will be used when the
+callback returns 0. If you want the existing behavior you should set the global
+default to PNG_HANDLE_CHUNK_IF_SAFE now; this is compatible with all current
+versions of libpng and with 1.7. Libpng 1.6 issues a warning if you keep the
+default, or PNG_HANDLE_CHUNK_NEVER, and the callback returns 0.
At this point, you can set up a callback function that will be
called after each row has been read, which you can use to control
a progress meter or the like. It's demonstrated in pngtest.c.
You must supply a function
- void read_row_callback(png_ptr ptr, png_uint_32 row,
- int pass);
+ void read_row_callback(png_structp png_ptr,
+ png_uint_32 row, int pass);
{
/* put your code here */
}
@@ -1144,6 +1077,19 @@ To inform libpng about your function, use
png_set_read_status_fn(png_ptr, read_row_callback);
+When this function is called the row has already been completely processed and
+the 'row' and 'pass' refer to the next row to be handled. For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0. For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes. Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass\-1'; if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+
.SS Unknown-chunk handling
Now you get to set the way the library processes unknown chunks in the
@@ -1155,21 +1101,30 @@ chunk types. To change this, you can call:
png_set_keep_unknown_chunks(png_ptr, keep,
chunk_list, num_chunks);
+
keep - 0: default unknown chunk handling
1: ignore; do not keep
2: keep only if safe-to-copy
3: keep even if unsafe-to-copy
+
You can use these definitions:
PNG_HANDLE_CHUNK_AS_DEFAULT 0
PNG_HANDLE_CHUNK_NEVER 1
PNG_HANDLE_CHUNK_IF_SAFE 2
PNG_HANDLE_CHUNK_ALWAYS 3
+
chunk_list - list of chunks affected (a byte string,
five bytes per chunk, NULL or '\0' if
- num_chunks is 0)
+ num_chunks is positive; ignored if
+ numchunks <= 0).
+
num_chunks - number of chunks affected; if 0, all
- unknown chunks are affected. If nonzero,
- only the chunks in the list are affected
+ unknown chunks are affected. If positive,
+ only the chunks in the list are affected,
+ and if negative all unknown chunks and
+ all known chunks except for the IHDR,
+ PLTE, tRNS, IDAT, and IEND chunks are
+ affected.
Unknown chunks declared in this way will be saved as raw data onto a
list of png_unknown_chunk structures. If a chunk that is normally
@@ -1178,6 +1133,8 @@ according to the "keep" directive. If a chunk is named in successive
instances of png_set_keep_unknown_chunks(), the final instance will
take precedence. The IHDR and IEND chunks should not be named in
chunk_list; if they are, libpng will process them normally anyway.
+If you know that your application will never make use of some particular
+chunks, use PNG_HANDLE_CHUNK_NEVER (or 1) as demonstrated below.
Here is an example of the usage of png_set_keep_unknown_chunks(),
where the private "vpAg" chunk will later be processed by a user chunk
@@ -1200,40 +1157,49 @@ callback function:
...
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
- /* ignore all unknown chunks: */
- png_set_keep_unknown_chunks(read_ptr, 1, NULL, 0);
+ /* ignore all unknown chunks
+ * (use global setting "2" for libpng16 and earlier):
+ */
+ png_set_keep_unknown_chunks(read_ptr, 2, NULL, 0);
+
/* except for vpAg: */
png_set_keep_unknown_chunks(read_ptr, 2, vpAg, 1);
+
/* also ignore unused known chunks: */
png_set_keep_unknown_chunks(read_ptr, 1, unused_chunks,
- (int)sizeof(unused_chunks)/5);
+ (int)(sizeof unused_chunks)/5);
#endif
.SS User limits
The PNG specification allows the width and height of an image to be as
-large as 2^31-1 (0x7fffffff), or about 2.147 billion rows and columns.
-Since very few applications really need to process such large images,
-we have imposed an arbitrary 1-million limit on rows and columns.
+large as 2^(31\-1 (0x7fffffff), or about 2.147 billion rows and columns.
+For safety, libpng imposes a default limit of 1 million rows and columns.
Larger images will be rejected immediately with a png_error() call. If
-you wish to override this limit, you can use
+you wish to change these limits, you can use
png_set_user_limits(png_ptr, width_max, height_max);
-to set your own limits, or use width_max = height_max = 0x7fffffffL
-to allow all valid dimensions (libpng may reject some very large images
+to set your own limits (libpng may reject some very wide images
anyway because of potential buffer overflow conditions).
You should put this statement after you create the PNG structure and
before calling png_read_info(), png_read_png(), or png_process_data().
+
+When writing a PNG datastream, put this statement before calling
+png_write_info() or png_write_png().
+
If you need to retrieve the limits that are being applied, use
width_max = png_get_user_width_max(png_ptr);
height_max = png_get_user_height_max(png_ptr);
The PNG specification sets no limit on the number of ancillary chunks
-allowed in a PNG datastream. You can impose a limit on the total number
-of sPLT, tEXt, iTXt, zTXt, and unknown chunks that will be stored, with
+allowed in a PNG datastream. By default, libpng imposes a limit of
+a total of 1000 sPLT, tEXt, iTXt, zTXt, and unknown chunks to be stored.
+If you have set up both info_ptr and end_info_ptr, the limit applies
+separately to each. You can change the limit on the total number of such
+chunks that will be stored, with
png_set_chunk_cache_max(png_ptr, user_chunk_cache_max);
@@ -1241,8 +1207,436 @@ where 0x7fffffffL means unlimited. You can retrieve this limit with
chunk_cache_max = png_get_chunk_cache_max(png_ptr);
-This limit also applies to the number of buffers that can be allocated
-by png_decompress_chunk() while decompressing iTXt, zTXt, and iCCP chunks.
+Libpng imposes a limit of 8 Megabytes (8,000,000 bytes) on the amount of
+memory that any chunk other than IDAT can occupy, originally or when
+decompressed (prior to libpng-1.6.32 the limit was only applied to compressed
+chunks after decompression). You can change this limit with
+
+ png_set_chunk_malloc_max(png_ptr, user_chunk_malloc_max);
+
+and you can retrieve the limit with
+
+ chunk_malloc_max = png_get_chunk_malloc_max(png_ptr);
+
+Any chunks that would cause either of these limits to be exceeded will
+be ignored.
+
+.SS Information about your system
+
+If you intend to display the PNG or to incorporate it in other image data you
+need to tell libpng information about your display or drawing surface so that
+libpng can convert the values in the image to match the display.
+
+From libpng-1.5.4 this information can be set before reading the PNG file
+header. In earlier versions png_set_gamma() existed but behaved incorrectly if
+called before the PNG file header had been read and png_set_alpha_mode() did not
+exist.
+
+If you need to support versions prior to libpng-1.5.4 test the version number
+as illustrated below using "PNG_LIBPNG_VER >= 10504" and follow the procedures
+described in the appropriate manual page.
+
+You give libpng the encoding expected by your system expressed as a 'gamma'
+value. You can also specify a default encoding for the PNG file in
+case the required information is missing from the file. By default libpng
+assumes that the PNG data matches your system, to keep this default call:
+
+ png_set_gamma(png_ptr, screen_gamma, output_gamma);
+
+or you can use the fixed point equivalent:
+
+ png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma,
+ PNG_FP_1*output_gamma);
+
+If you don't know the gamma for your system it is probably 2.2 - a good
+approximation to the IEC standard for display systems (sRGB). If images are
+too contrasty or washed out you got the value wrong - check your system
+documentation!
+
+Many systems permit the system gamma to be changed via a lookup table in the
+display driver, a few systems, including older Macs, change the response by
+default. As of 1.5.4 three special values are available to handle common
+situations:
+
+ PNG_DEFAULT_sRGB: Indicates that the system conforms to the
+ IEC 61966-2-1 standard. This matches almost
+ all systems.
+ PNG_GAMMA_MAC_18: Indicates that the system is an older
+ (pre Mac OS 10.6) Apple Macintosh system with
+ the default settings.
+ PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates
+ that the system expects data with no gamma
+ encoding.
+
+You would use the linear (unencoded) value if you need to process the pixel
+values further because this avoids the need to decode and re-encode each
+component value whenever arithmetic is performed. A lot of graphics software
+uses linear values for this reason, often with higher precision component values
+to preserve overall accuracy.
+
+
+The output_gamma value expresses how to decode the output values, not how
+they are encoded. The values used correspond to the normal numbers used to
+describe the overall gamma of a computer display system; for example 2.2 for
+an sRGB conformant system. The values are scaled by 100000 in the _fixed
+version of the API (so 220000 for sRGB.)
+
+The inverse of the value is always used to provide a default for the PNG file
+encoding if it has no gAMA chunk and if png_set_gamma() has not been called
+to override the PNG gamma information.
+
+When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
+opaque pixels however pixels with lower alpha values are not encoded,
+regardless of the output gamma setting.
+
+When the standard Porter Duff handling is requested with mode 1 the output
+encoding is set to be linear and the output_gamma value is only relevant
+as a default for input data that has no gamma information. The linear output
+encoding will be overridden if png_set_gamma() is called - the results may be
+highly unexpected!
+
+The following numbers are derived from the sRGB standard and the research
+behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
+0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
+correction required to take account of any differences in the color
+environment of the original scene and the intended display environment; the
+value expresses how to *decode* the image for display, not how the original
+data was *encoded*.
+
+sRGB provides a peg for the PNG standard by defining a viewing environment.
+sRGB itself, and earlier TV standards, actually use a more complex transform
+(a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
+limited to simple power laws.) By saying that an image for direct display on
+an sRGB conformant system should be stored with a gAMA chunk value of 45455
+(11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
+makes it possible to derive values for other display systems and
+environments.
+
+The Mac value is deduced from the sRGB based on an assumption that the actual
+extra viewing correction used in early Mac display systems was implemented as
+a power 1.45 lookup table.
+
+Any system where a programmable lookup table is used or where the behavior of
+the final display device characteristics can be changed requires system
+specific code to obtain the current characteristic. However this can be
+difficult and most PNG gamma correction only requires an approximate value.
+
+By default, if png_set_alpha_mode() is not called, libpng assumes that all
+values are unencoded, linear, values and that the output device also has a
+linear characteristic. This is only very rarely correct - it is invariably
+better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
+default if you don't know what the right answer is!
+
+The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
+10.6) which used a correction table to implement a somewhat lower gamma on an
+otherwise sRGB system.
+
+Both these values are reserved (not simple gamma values) in order to allow
+more precise correction internally in the future.
+
+NOTE: the values can be passed to either the fixed or floating
+point APIs, but the floating point API will also accept floating point
+values.
+
+The second thing you may need to tell libpng about is how your system handles
+alpha channel information. Some, but not all, PNG files contain an alpha
+channel. To display these files correctly you need to compose the data onto a
+suitable background, as described in the PNG specification.
+
+Libpng only supports composing onto a single color (using png_set_background;
+see below). Otherwise you must do the composition yourself and, in this case,
+you may need to call png_set_alpha_mode:
+
+ #if PNG_LIBPNG_VER >= 10504
+ png_set_alpha_mode(png_ptr, mode, screen_gamma);
+ #else
+ png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma);
+ #endif
+
+The screen_gamma value is the same as the argument to png_set_gamma; however,
+how it affects the output depends on the mode. png_set_alpha_mode() sets the
+file gamma default to 1/screen_gamma, so normally you don't need to call
+png_set_gamma. If you need different defaults call png_set_gamma() before
+png_set_alpha_mode() - if you call it after it will override the settings made
+by png_set_alpha_mode().
+
+The mode is as follows:
+
+ PNG_ALPHA_PNG: The data is encoded according to the PNG
+specification. Red, green and blue, or gray, components are
+gamma encoded color values and are not premultiplied by the
+alpha value. The alpha value is a linear measure of the
+contribution of the pixel to the corresponding final output pixel.
+
+You should normally use this format if you intend to perform
+color correction on the color values; most, maybe all, color
+correction software has no handling for the alpha channel and,
+anyway, the math to handle pre-multiplied component values is
+unnecessarily complex.
+
+Before you do any arithmetic on the component values you need
+to remove the gamma encoding and multiply out the alpha
+channel. See the PNG specification for more detail. It is
+important to note that when an image with an alpha channel is
+scaled, linear encoded, pre-multiplied component values must
+be used!
+
+The remaining modes assume you don't need to do any further color correction or
+that if you do, your color correction software knows all about alpha (it
+probably doesn't!). They 'associate' the alpha with the color information by
+storing color channel values that have been scaled by the alpha. The
+advantage is that the color channels can be resampled (the image can be
+scaled) in this form. The disadvantage is that normal practice is to store
+linear, not (gamma) encoded, values and this requires 16-bit channels for
+still images rather than the 8-bit channels that are just about sufficient if
+gamma encoding is used. In addition all non-transparent pixel values,
+including completely opaque ones, must be gamma encoded to produce the final
+image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
+described below (the latter being the two common names for associated alpha
+color channels). Note that PNG files always contain non-associated color
+channels; png_set_alpha_mode() with one of the modes causes the decoder to
+convert the pixels to an associated form before returning them to your
+application.
+
+Since it is not necessary to perform arithmetic on opaque color values so
+long as they are not to be resampled and are in the final color space it is
+possible to optimize the handling of alpha by storing the opaque pixels in
+the PNG format (adjusted for the output color space) while storing partially
+opaque pixels in the standard, linear, format. The accuracy required for
+standard alpha composition is relatively low, because the pixels are
+isolated, therefore typically the accuracy loss in storing 8-bit linear
+values is acceptable. (This is not true if the alpha channel is used to
+simulate transparency over large areas - use 16 bits or the PNG mode in
+this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
+treated as opaque only if the alpha value is equal to the maximum value.
+
+ PNG_ALPHA_STANDARD: The data libpng produces is encoded in the
+standard way assumed by most correctly written graphics software.
+The gamma encoding will be removed by libpng and the
+linear component values will be pre-multiplied by the
+alpha channel.
+
+With this format the final image must be re-encoded to
+match the display gamma before the image is displayed.
+If your system doesn't do that, yet still seems to
+perform arithmetic on the pixels without decoding them,
+it is broken - check out the modes below.
+
+With PNG_ALPHA_STANDARD libpng always produces linear
+component values, whatever screen_gamma you supply. The
+screen_gamma value is, however, used as a default for
+the file gamma if the PNG file has no gamma information.
+
+If you call png_set_gamma() after png_set_alpha_mode() you
+will override the linear encoding. Instead the
+pre-multiplied pixel values will be gamma encoded but
+the alpha channel will still be linear. This may
+actually match the requirements of some broken software,
+but it is unlikely.
+
+While linear 8-bit data is often used it has
+insufficient precision for any image with a reasonable
+dynamic range. To avoid problems, and if your software
+supports it, use png_set_expand_16() to force all
+components to 16 bits.
+
+ PNG_ALPHA_OPTIMIZED: This mode is the same as PNG_ALPHA_STANDARD
+except that completely opaque pixels are gamma encoded according to
+the screen_gamma value. Pixels with alpha less than 1.0
+will still have linear components.
+
+Use this format if you have control over your
+compositing software and so don't do other arithmetic
+(such as scaling) on the data you get from libpng. Your
+compositing software can simply copy opaque pixels to
+the output but still has linear values for the
+non-opaque pixels.
+
+In normal compositing, where the alpha channel encodes
+partial pixel coverage (as opposed to broad area
+translucency), the inaccuracies of the 8-bit
+representation of non-opaque pixels are irrelevant.
+
+You can also try this format if your software is broken;
+it might look better.
+
+ PNG_ALPHA_BROKEN: This is PNG_ALPHA_STANDARD; however, all component
+values, including the alpha channel are gamma encoded. This is
+broken because, in practice, no implementation that uses this choice
+correctly undoes the encoding before handling alpha composition. Use this
+choice only if other serious errors in the software or hardware you use
+mandate it. In most cases of broken software or hardware the bug in the
+final display manifests as a subtle halo around composited parts of the
+image. You may not even perceive this as a halo; the composited part of
+the image may simply appear separate from the background, as though it had
+been cut out of paper and pasted on afterward.
+
+If you don't have to deal with bugs in software or hardware, or if you can fix
+them, there are three recommended ways of using png_set_alpha_mode():
+
+ png_set_alpha_mode(png_ptr, PNG_ALPHA_PNG,
+ screen_gamma);
+
+You can do color correction on the result (libpng does not currently
+support color correction internally). When you handle the alpha channel
+you need to undo the gamma encoding and multiply out the alpha.
+
+ png_set_alpha_mode(png_ptr, PNG_ALPHA_STANDARD,
+ screen_gamma);
+ png_set_expand_16(png_ptr);
+
+If you are using the high level interface, don't call png_set_expand_16();
+instead pass PNG_TRANSFORM_EXPAND_16 to the interface.
+
+With this mode you can't do color correction, but you can do arithmetic,
+including composition and scaling, on the data without further processing.
+
+ png_set_alpha_mode(png_ptr, PNG_ALPHA_OPTIMIZED,
+ screen_gamma);
+
+You can avoid the expansion to 16-bit components with this mode, but you
+lose the ability to scale the image or perform other linear arithmetic.
+All you can do is compose the result onto a matching output. Since this
+mode is libpng-specific you also need to write your own composition
+software.
+
+The following are examples of calls to png_set_alpha_mode to achieve the
+required overall gamma correction and, where necessary, alpha
+premultiplication.
+
+ png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+
+Choices for the alpha_mode are
+
+ PNG_ALPHA_PNG 0 /* according to the PNG standard */
+ PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
+ PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
+ PNG_ALPHA_PREMULTIPLIED 1 /* as above */
+ PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
+ PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
+
+PNG_ALPHA_PNG is the default libpng handling of the alpha channel. It is not
+pre-multiplied into the color components. In addition the call states
+that the output is for a sRGB system and causes all PNG files without gAMA
+chunks to be assumed to be encoded using sRGB.
+
+ png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+
+In this case the output is assumed to be something like an sRGB conformant
+display preceded by a power-law lookup table of power 1.45. This is how
+early Mac systems behaved.
+
+ png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
+
+This is the classic Jim Blinn approach and will work in academic
+environments where everything is done by the book. It has the shortcoming
+of assuming that input PNG data with no gamma information is linear - this
+is unlikely to be correct unless the PNG files were generated locally.
+Most of the time the output precision will be so low as to show
+significant banding in dark areas of the image.
+
+ png_set_expand_16(pp);
+ png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
+
+This is a somewhat more realistic Jim Blinn inspired approach. PNG files
+are assumed to have the sRGB encoding if not marked with a gamma value and
+the output is always 16 bits per component. This permits accurate scaling
+and processing of the data. If you know that your input PNG files were
+generated locally you might need to replace PNG_DEFAULT_sRGB with the
+correct value for your system.
+
+ png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
+
+If you just need to composite the PNG image onto an existing background
+and if you control the code that does this you can use the optimization
+setting. In this case you just copy completely opaque pixels to the
+output. For pixels that are not completely transparent (you just skip
+those) you do the composition math using png_composite or png_composite_16
+below then encode the resultant 8-bit or 16-bit values to match the output
+encoding.
+
+ Other cases
+
+If neither the PNG nor the standard linear encoding work for you because
+of the software or hardware you use then you have a big problem. The PNG
+case will probably result in halos around the image. The linear encoding
+will probably result in a washed out, too bright, image (it's actually too
+contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
+substantially reduce the halos. Alternatively try:
+
+ png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
+
+This option will also reduce the halos, but there will be slight dark
+halos round the opaque parts of the image where the background is light.
+In the OPTIMIZED mode the halos will be light halos where the background
+is dark. Take your pick - the halos are unavoidable unless you can get
+your hardware/software fixed! (The OPTIMIZED approach is slightly
+faster.)
+
+When the default gamma of PNG files doesn't match the output gamma.
+If you have PNG files with no gamma information png_set_alpha_mode allows
+you to provide a default gamma, but it also sets the output gamma to the
+matching value. If you know your PNG files have a gamma that doesn't
+match the output you can take advantage of the fact that
+png_set_alpha_mode always sets the output gamma but only sets the PNG
+default if it is not already set:
+
+ png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
+ png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
+
+The first call sets both the default and the output gamma values, the
+second call overrides the output gamma without changing the default. This
+is easier than achieving the same effect with png_set_gamma. You must use
+PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
+fire if more than one call to png_set_alpha_mode and png_set_background is
+made in the same read operation, however multiple calls with PNG_ALPHA_PNG
+are ignored.
+
+If you don't need, or can't handle, the alpha channel you can call
+png_set_background() to remove it by compositing against a fixed color. Don't
+call png_set_strip_alpha() to do this - it will leave spurious pixel values in
+transparent parts of this image.
+
+ png_set_background(png_ptr, &background_color,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0, 1);
+
+The background_color is an RGB or grayscale value according to the data format
+libpng will produce for you. Because you don't yet know the format of the PNG
+file, if you call png_set_background at this point you must arrange for the
+format produced by libpng to always have 8-bit or 16-bit components and then
+store the color as an 8-bit or 16-bit color as appropriate. The color contains
+separate gray and RGB component values, so you can let libpng produce gray or
+RGB output according to the input format, but low bit depth grayscale images
+must always be converted to at least 8-bit format. (Even though low bit depth
+grayscale images can't have an alpha channel they can have a transparent
+color!)
+
+You set the transforms you need later, either as flags to the high level
+interface or libpng API calls for the low level interface. For reference the
+settings and API calls required are:
+
+8-bit values:
+ PNG_TRANSFORM_SCALE_16 | PNG_EXPAND
+ png_set_expand(png_ptr); png_set_scale_16(png_ptr);
+
+ If you must get exactly the same inaccurate results
+ produced by default in versions prior to libpng-1.5.4,
+ use PNG_TRANSFORM_STRIP_16 and png_set_strip_16(png_ptr)
+ instead.
+
+16-bit values:
+ PNG_TRANSFORM_EXPAND_16
+ png_set_expand_16(png_ptr);
+
+In either case palette image data will be expanded to RGB. If you just want
+color data you can add PNG_TRANSFORM_GRAY_TO_RGB or png_set_gray_to_rgb(png_ptr)
+to the list.
+
+Calling png_set_background before the PNG file header is read will not work
+prior to libpng-1.5.4. Because the failure may result in unexpected warnings or
+errors it is therefore much safer to call png_set_background after the head has
+been read. Unfortunately this means that prior to libpng-1.5.4 it cannot be
+used with the high level interface.
.SS The high-level read interface
@@ -1253,8 +1647,10 @@ the entire image into memory, and (b) the input transformations
you want to do are limited to the following set:
PNG_TRANSFORM_IDENTITY No transformation
- PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to
- 8 bits
+ PNG_TRANSFORM_SCALE_16 Strip 16-bit samples to
+ 8-bit accurately
+ PNG_TRANSFORM_STRIP_16 Chop 16-bit samples to
+ 8-bit less accurately
PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
samples to bytes
@@ -1273,9 +1669,10 @@ you want to do are limited to the following set:
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
PNG_TRANSFORM_GRAY_TO_RGB Expand grayscale samples
to RGB (or GA to RGBA)
+ PNG_TRANSFORM_EXPAND_16 Expand samples to 16 bits
(This excludes setting a background color, doing gamma transformation,
-dithering, and setting filler.) If this is the case, simply do this:
+quantizing, and setting filler.) If this is the case, simply do this:
png_read_png(png_ptr, info_ptr, png_transforms, NULL)
@@ -1302,29 +1699,47 @@ where row_pointers is an array of pointers to the pixel data for each row:
If you know your image size and pixel size ahead of time, you can allocate
row_pointers prior to calling png_read_png() with
- if (height > PNG_UINT_32_MAX/png_sizeof(png_byte))
+ if (height > PNG_UINT_32_MAX/(sizeof (png_byte)))
png_error (png_ptr,
- "Image is too tall to process in memory");
+ "Image is too tall to process in memory");
+
if (width > PNG_UINT_32_MAX/pixel_size)
png_error (png_ptr,
- "Image is too wide to process in memory");
+ "Image is too wide to process in memory");
+
row_pointers = png_malloc(png_ptr,
- height*png_sizeof(png_bytep));
+ height*(sizeof (png_bytep)));
+
for (int i=0; i<height, i++)
row_pointers[i]=NULL; /* security precaution */
+
for (int i=0; i<height, i++)
row_pointers[i]=png_malloc(png_ptr,
- width*pixel_size);
+ width*pixel_size);
+
png_set_rows(png_ptr, info_ptr, &row_pointers);
Alternatively you could allocate your image in one big block and define
-row_pointers[i] to point into the proper places in your block.
+row_pointers[i] to point into the proper places in your block, but first
+be sure that your platform is able to allocate such a large buffer:
+
+ /* Guard against integer overflow */
+ if (height > PNG_SIZE_MAX/(width*pixel_size)) {
+ png_error(png_ptr,"image_data buffer would be too large");
+ }
+
+ png_bytep buffer=png_malloc(png_ptr,height*width*pixel_size);
+
+ for (int i=0; i<height, i++)
+ row_pointers[i]=buffer+i*width*pixel_size;
+
+ png_set_rows(png_ptr, info_ptr, &row_pointers);
If you use png_set_rows(), the application is responsible for freeing
row_pointers (and row_pointers[i], if they were separately allocated).
If you don't allocate row_pointers ahead of time, png_read_png() will
-do it, and it'll be free'ed when you call png_destroy_*().
+do it, and it'll be free'ed by libpng when you call png_destroy_*().
.SS The low-level read interface
@@ -1336,6 +1751,22 @@ call to png_read_info().
This will process all chunks up to but not including the image data.
+This also copies some of the data from the PNG file into the decode structure
+for use in later transformations. Important information copied in is:
+
+1) The PNG file gamma from the gAMA chunk. This overwrites the default value
+provided by an earlier call to png_set_gamma or png_set_alpha_mode.
+
+2) Prior to libpng-1.5.4 the background color from a bKGd chunk. This
+damages the information provided by an earlier call to png_set_background
+resulting in unexpected behavior. Libpng-1.5.4 no longer does this.
+
+3) The number of significant bits in each component value. Libpng uses this to
+optimize gamma handling by reducing the internal lookup table sizes.
+
+4) The transparent color information from a tRNS chunk. This can be modified by
+a later call to png_set_tRNS.
+
.SS Querying the info structure
Functions are used to get the information from the info_ptr once it
@@ -1348,13 +1779,16 @@ in until png_read_end() has read the chunk data following the image.
width - holds the width of the image
in pixels (up to 2^31).
+
height - holds the height of the image
in pixels (up to 2^31).
+
bit_depth - holds the bit depth of one of the
image channels. (valid values are
1, 2, 4, 8, 16 and depend also on
the color_type. See also
significant bits (sBIT) below).
+
color_type - describes which color/alpha channels
are present.
PNG_COLOR_TYPE_GRAY
@@ -1372,51 +1806,68 @@ in until png_read_end() has read the chunk data following the image.
PNG_COLOR_MASK_COLOR
PNG_COLOR_MASK_ALPHA
+ interlace_type - (PNG_INTERLACE_NONE or
+ PNG_INTERLACE_ADAM7)
+
+ compression_type - (must be PNG_COMPRESSION_TYPE_BASE
+ for PNG 1.0)
+
filter_method - (must be PNG_FILTER_TYPE_BASE
for PNG 1.0, and can also be
PNG_INTRAPIXEL_DIFFERENCING if
the PNG datastream is embedded in
a MNG-1.0 datastream)
- compression_type - (must be PNG_COMPRESSION_TYPE_BASE
- for PNG 1.0)
- interlace_type - (PNG_INTERLACE_NONE or
- PNG_INTERLACE_ADAM7)
- Any or all of interlace_type, compression_type, or
- filter_method can be NULL if you are
- not interested in their values.
+ Any of width, height, color_type, bit_depth,
+ interlace_type, compression_type, or filter_method can
+ be NULL if you are not interested in their values.
Note that png_get_IHDR() returns 32-bit data into
the application's width and height variables.
- This is an unsafe situation if these are 16-bit
+ This is an unsafe situation if these are not png_uint_32
variables. In such situations, the
png_get_image_width() and png_get_image_height()
functions described below are safer.
width = png_get_image_width(png_ptr,
info_ptr);
+
height = png_get_image_height(png_ptr,
info_ptr);
+
bit_depth = png_get_bit_depth(png_ptr,
info_ptr);
+
color_type = png_get_color_type(png_ptr,
info_ptr);
- filter_method = png_get_filter_type(png_ptr,
+
+ interlace_type = png_get_interlace_type(png_ptr,
info_ptr);
+
compression_type = png_get_compression_type(png_ptr,
info_ptr);
- interlace_type = png_get_interlace_type(png_ptr,
+
+ filter_method = png_get_filter_type(png_ptr,
info_ptr);
channels = png_get_channels(png_ptr, info_ptr);
+
channels - number of channels of info for the
color type (valid values are 1 (GRAY,
PALETTE), 2 (GRAY_ALPHA), 3 (RGB),
4 (RGB_ALPHA or RGB + filler byte))
+
rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+
rowbytes - number of bytes needed to hold a row
+ This value, the bit_depth, color_type,
+ and the number of channels can change
+ if you use transforms such as
+ png_set_expand(). See
+ png_read_update_info(), below.
signature = png_get_signature(png_ptr, info_ptr);
+
signature - holds the signature read from the
file (if any). The data is kept in
the same offset it would be if the
@@ -1434,18 +1885,62 @@ data has been read, or zero if it is missing. The parameters to the
png_get_<chunk> are set directly if they are simple data types, or a
pointer into the info_ptr is returned for any complex types.
+The colorspace data from gAMA, cHRM, sRGB, iCCP, and sBIT chunks
+is simply returned to give the application information about how the
+image was encoded. Libpng itself only does transformations using the file
+gamma when combining semitransparent pixels with the background color, and,
+since libpng-1.6.0, when converting between 8-bit sRGB and 16-bit linear pixels
+within the simplified API. Libpng also uses the file gamma when converting
+RGB to gray, beginning with libpng-1.0.5, if the application calls
+png_set_rgb_to_gray()).
+
png_get_PLTE(png_ptr, info_ptr, &palette,
&num_palette);
+
palette - the palette for the file
(array of png_color)
+
num_palette - number of entries in the palette
- png_get_gAMA(png_ptr, info_ptr, &gamma);
- gamma - the gamma the file is written
- at (PNG_INFO_gAMA)
+ png_get_gAMA(png_ptr, info_ptr, &file_gamma);
+ png_get_gAMA_fixed(png_ptr, info_ptr, &int_file_gamma);
+
+ file_gamma - the gamma at which the file is
+ written (PNG_INFO_gAMA)
+
+ int_file_gamma - 100,000 times the gamma at which the
+ file is written
+
+ png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x,
+ &red_y, &green_x, &green_y, &blue_x, &blue_y)
+ png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z,
+ &green_X, &green_Y, &green_Z, &blue_X, &blue_Y,
+ &blue_Z)
+ png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x,
+ &int_white_y, &int_red_x, &int_red_y,
+ &int_green_x, &int_green_y, &int_blue_x,
+ &int_blue_y)
+ png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y,
+ &int_red_Z, &int_green_X, &int_green_Y,
+ &int_green_Z, &int_blue_X, &int_blue_Y,
+ &int_blue_Z)
+
+ {white,red,green,blue}_{x,y}
+ A color space encoding specified using the
+ chromaticities of the end points and the
+ white point. (PNG_INFO_cHRM)
+
+ {red,green,blue}_{X,Y,Z}
+ A color space encoding specified using the
+ encoding end points - the CIE tristimulus
+ specification of the intended color of the red,
+ green and blue channels in the PNG RGB data.
+ The white point is simply the sum of the three
+ end points. (PNG_INFO_cHRM)
png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
- srgb_intent - the rendering intent (PNG_INFO_sRGB)
+
+ srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk
means that the pixel data is in the
sRGB color space. This chunk also
@@ -1454,75 +1949,108 @@ pointer into the info_ptr is returned for any complex types.
png_get_iCCP(png_ptr, info_ptr, &name,
&compression_type, &profile, &proflen);
- name - The profile name.
- compression - The compression type; always
- PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
- You may give NULL to this argument to
- ignore it.
- profile - International Color Consortium color
- profile data. May contain NULs.
- proflen - length of profile data in bytes.
+
+ name - The profile name.
+
+ compression_type - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+
+ proflen - length of profile data in bytes.
png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+
sig_bit - the number of significant bits for
(PNG_INFO_sBIT) each of the gray,
red, green, and blue channels,
whichever are appropriate for the
given color type (png_color_16)
- png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
- &trans_values);
- trans - array of transparent
+ png_get_tRNS(png_ptr, info_ptr, &trans_alpha,
+ &num_trans, &trans_color);
+
+ trans_alpha - array of alpha (transparency)
entries for palette (PNG_INFO_tRNS)
- trans_values - graylevel or color sample values of
- the single transparent color for
- non-paletted images (PNG_INFO_tRNS)
+
num_trans - number of transparent entries
(PNG_INFO_tRNS)
+ trans_color - graylevel or color sample values of
+ the single transparent color for
+ non-paletted images (PNG_INFO_tRNS)
+
+ png_get_eXIf_1(png_ptr, info_ptr, &num_exif, &exif);
+ (PNG_INFO_eXIf)
+
+ exif - Exif profile (array of png_byte)
+
png_get_hIST(png_ptr, info_ptr, &hist);
(PNG_INFO_hIST)
+
hist - histogram of palette (array of
png_uint_16)
png_get_tIME(png_ptr, info_ptr, &mod_time);
+
mod_time - time image was last modified
(PNG_VALID_tIME)
png_get_bKGD(png_ptr, info_ptr, &background);
- background - background color (PNG_VALID_bKGD)
+
+ background - background color (of type
+ png_color_16p) (PNG_VALID_bKGD)
valid 16-bit red, green and blue
values, regardless of color_type
num_comments = png_get_text(png_ptr, info_ptr,
&text_ptr, &num_text);
+
num_comments - number of comments
+
text_ptr - array of png_text holding image
comments
+
text_ptr[i].compression - type of compression used
on "text" PNG_TEXT_COMPRESSION_NONE
PNG_TEXT_COMPRESSION_zTXt
PNG_ITXT_COMPRESSION_NONE
PNG_ITXT_COMPRESSION_zTXt
+
text_ptr[i].key - keyword for comment. Must contain
1-79 characters.
+
text_ptr[i].text - text comments for current
keyword. Can be empty.
+
text_ptr[i].text_length - length of text string,
after decompression, 0 for iTXt
+
text_ptr[i].itxt_length - length of itxt string,
after decompression, 0 for tEXt/zTXt
+
text_ptr[i].lang - language of comment (empty
string for unknown).
+
text_ptr[i].lang_key - keyword in UTF-8
(empty string for unknown).
+
Note that the itxt_length, lang, and lang_key
- members of the text_ptr structure only exist
- when the library is built with iTXt chunk support.
+ members of the text_ptr structure only exist when the
+ library is built with iTXt chunk support. Prior to
+ libpng-1.4.0 the library was built by default without
+ iTXt support. Also note that when iTXt is supported,
+ they contain NULL pointers when the "compression"
+ field contains PNG_TEXT_COMPRESSION_NONE or
+ PNG_TEXT_COMPRESSION_zTXt.
num_text - number of comments (same as
num_comments; you can put NULL here
to avoid the duplication)
+
Note while png_set_text() will accept text, language,
and translated keywords that can be NULL pointers, the
structure returned by png_get_text will always contain
@@ -1531,90 +2059,137 @@ pointer into the info_ptr is returned for any complex types.
num_spalettes = png_get_sPLT(png_ptr, info_ptr,
&palette_ptr);
+
+ num_spalettes - number of sPLT chunks read.
+
palette_ptr - array of palette structures holding
contents of one or more sPLT chunks
read.
- num_spalettes - number of sPLT chunks read.
png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
&unit_type);
+
offset_x - positive offset from the left edge
- of the screen
+ of the screen (can be negative)
+
offset_y - positive offset from the top edge
- of the screen
+ of the screen (can be negative)
+
unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
&unit_type);
+
res_x - pixels/unit physical resolution in
x direction
+
res_y - pixels/unit physical resolution in
x direction
+
unit_type - PNG_RESOLUTION_UNKNOWN,
PNG_RESOLUTION_METER
png_get_sCAL(png_ptr, info_ptr, &unit, &width,
&height)
+
unit - physical scale units (an integer)
+
width - width of a pixel in physical scale units
+
height - height of a pixel in physical scale units
(width and height are doubles)
png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
&height)
+
unit - physical scale units (an integer)
+
width - width of a pixel in physical scale units
+ (expressed as a string)
+
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
num_unknown_chunks = png_get_unknown_chunks(png_ptr,
info_ptr, &unknowns)
+
unknowns - array of png_unknown_chunk
structures holding unknown chunks
+
unknowns[i].name - name of unknown chunk
+
unknowns[i].data - data of unknown chunk
+
unknowns[i].size - size of unknown chunk's data
+
unknowns[i].location - position of chunk in file
The value of "i" corresponds to the order in which the
chunks were read from the PNG file or inserted with the
png_set_unknown_chunks() function.
+ The value of "location" is a bitwise "or" of
+
+ PNG_HAVE_IHDR (0x01)
+ PNG_HAVE_PLTE (0x02)
+ PNG_AFTER_IDAT (0x08)
+
The data from the pHYs chunk can be retrieved in several convenient
forms:
res_x = png_get_x_pixels_per_meter(png_ptr,
info_ptr)
+
res_y = png_get_y_pixels_per_meter(png_ptr,
info_ptr)
+
res_x_and_y = png_get_pixels_per_meter(png_ptr,
info_ptr)
+
res_x = png_get_x_pixels_per_inch(png_ptr,
info_ptr)
+
res_y = png_get_y_pixels_per_inch(png_ptr,
info_ptr)
+
res_x_and_y = png_get_pixels_per_inch(png_ptr,
info_ptr)
+
aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
info_ptr)
- (Each of these returns 0 [signifying "unknown"] if
+ Each of these returns 0 [signifying "unknown"] if
the data is not present or if res_x is 0;
- res_x_and_y is 0 if res_x != res_y)
+ res_x_and_y is 0 if res_x != res_y
+
+ Note that because of the way the resolutions are
+ stored internally, the inch conversions won't
+ come out to exactly even number. For example,
+ 72 dpi is stored as 0.28346 pixels/meter, and
+ when this is retrieved it is 71.9988 dpi, so
+ be sure to round the returned value appropriately
+ if you want to display a reasonable-looking result.
The data from the oFFs chunk can be retrieved in several convenient
forms:
x_offset = png_get_x_offset_microns(png_ptr, info_ptr);
+
y_offset = png_get_y_offset_microns(png_ptr, info_ptr);
+
x_offset = png_get_x_offset_inches(png_ptr, info_ptr);
+
y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
- (Each of these returns 0 [signifying "unknown" if both
+ Each of these returns 0 [signifying "unknown" if both
x and y are 0] if the data is not present or if the
- chunk is present but the unit is the pixel)
+ chunk is present but the unit is the pixel. The
+ remark about inexact inch conversions applies here
+ as well, because a value in inches can't always be
+ converted to microns and back without some loss
+ of precision.
-For more information, see the png_info definition in png.h and the
+For more information, see the
PNG specification for chunk contents. Be careful with trusting
rowbytes, as some of the transformations could increase the space
needed to hold a row (expand, filler, gray_to_rgb, etc.).
@@ -1649,32 +2224,36 @@ to handle any special transformations of the image data. The various
ways to transform the data will be described in the order that they
should occur. This is important, as some of these change the color
type and/or bit depth of the data, and some others only work on
-certain color types and bit depths. Even though each transformation
-checks to see if it has data that it can do something with, you should
-make sure to only enable a transformation if it will be valid for the
-data. For example, don't swap red and blue on grayscale data.
+certain color types and bit depths.
+
+Transformations you request are ignored if they don't have any meaning for a
+particular input data format. However some transformations can have an effect
+as a result of a previous transformation. If you specify a contradictory set of
+transformations, for example both adding and removing the alpha channel, you
+cannot predict the final result.
-The colors used for the background and transparency values should be
-supplied in the same format/depth as the current image data. They
-are stored in the same format/depth as the image data in a bKGD or tRNS
-chunk, so this is what libpng expects for this data. The colors are
-transformed to keep in sync with the image data when an application
-calls the png_read_update_info() routine (see below).
+The color used for the transparency values should be supplied in the same
+format/depth as the current image data. It is stored in the same format/depth
+as the image data in a tRNS chunk, so this is what libpng expects for this data.
+
+The color used for the background value depends on the need_expand argument as
+described below.
Data will be decoded into the supplied row buffers packed into bytes
unless the library has been told to transform it into another format.
For example, 4 bit/pixel paletted or grayscale data will be returned
-2 pixels/byte with the leftmost pixel in the high-order bits of the
-byte, unless png_set_packing() is called. 8-bit RGB data will be stored
+2 pixels/byte with the leftmost pixel in the high-order bits of the byte,
+unless png_set_packing() is called. 8-bit RGB data will be stored
in RGB RGB RGB format unless png_set_filler() or png_set_add_alpha()
is called to insert filler bytes, either before or after each RGB triplet.
+
16-bit RGB data will be returned RRGGBB RRGGBB, with the most significant
-byte of the color value first, unless png_set_strip_16() is called to
+byte of the color value first, unless png_set_scale_16() is called to
transform it to regular RGB RGB triplets, or png_set_filler() or
-png_set_add alpha() is called to insert filler bytes, either before or
-after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can
-be modified with
-png_set_filler(), png_set_add_alpha(), or png_set_strip_16().
+png_set_add alpha() is called to insert two filler bytes, either before
+or after each RRGGBB triplet. Similarly, 8-bit or 16-bit grayscale data can
+be modified with png_set_filler(), png_set_add_alpha(), png_set_strip_16(),
+or png_set_scale_16().
The following code transforms grayscale images of less than 8 to 8 bits,
changes paletted images to RGB, and adds a full alpha channel if there is
@@ -1685,13 +2264,13 @@ viewing application that wishes to treat all images in the same way.
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(png_ptr);
- if (color_type == PNG_COLOR_TYPE_GRAY &&
- bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
-
if (png_get_valid(png_ptr, info_ptr,
PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
-These three functions are actually aliases for png_set_expand(), added
+ if (color_type == PNG_COLOR_TYPE_GRAY &&
+ bit_depth < 8) png_set_expand_gray_1_2_4_to_8(png_ptr);
+
+The first two functions are actually aliases for png_set_expand(), added
in libpng version 1.0.4, with the function names expanded to improve code
readability. In some future version they may actually do different
things.
@@ -1699,56 +2278,93 @@ things.
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
added. It expands the sample depth without changing tRNS to alpha.
-As of libpng version 1.2.44, not all possible expansions are supported.
+As of libpng version 1.5.2, png_set_expand_16() was added. It behaves as
+png_set_expand(); however, the resultant channels have 16 bits rather than 8.
+Use this when the output color or gray channels are made linear to avoid fairly
+severe accuracy loss.
+
+ if (bit_depth < 16)
+ png_set_expand_16(png_ptr);
+
+PNG can have files with 16 bits per channel. If you only can handle
+8 bits per channel, this will strip the pixels down to 8-bit.
+
+ if (bit_depth == 16)
+#if PNG_LIBPNG_VER >= 10504
+ png_set_scale_16(png_ptr);
+#else
+ png_set_strip_16(png_ptr);
+#endif
+
+(The more accurate "png_set_scale_16()" API became available in libpng version
+1.5.4).
+
+If you need to process the alpha channel on the image separately from the image
+data (for example if you convert it to a bitmap mask) it is possible to have
+libpng strip the channel leaving just RGB or gray data:
+
+ if (color_type & PNG_COLOR_MASK_ALPHA)
+ png_set_strip_alpha(png_ptr);
+
+If you strip the alpha channel you need to find some other way of dealing with
+the information. If, instead, you want to convert the image to an opaque
+version with no alpha channel use png_set_background; see below.
+
+As of libpng version 1.5.2, almost all useful expansions are supported, the
+major ommissions are conversion of grayscale to indexed images (which can be
+done trivially in the application) and conversion of indexed to grayscale (which
+can be done by a trivial manipulation of the palette.)
In the following table, the 01 means grayscale with depth<8, 31 means
indexed with depth<8, other numerals represent the color type, "T" means
the tRNS chunk is present, A means an alpha channel is present, and O
means tRNS or alpha is present but all pixels in the image are opaque.
- FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O
+ FROM 01 31 0 0T 0O 2 2T 2O 3 3T 3O 4A 4O 6A 6O
TO
- 01 -
- 31 -
- 0 1 -
- 0T -
- 0O -
- 2 GX -
- 2T -
- 2O -
- 3 1 -
- 3T -
- 3O -
- 4A T -
- 4O -
- 6A GX TX TX -
- 6O GX TX -
+ 01 - [G] - - - - - - - - - - - - -
+ 31 [Q] Q [Q] [Q] [Q] Q Q Q Q Q Q [Q] [Q] Q Q
+ 0 1 G + . . G G G G G G B B GB GB
+ 0T lt Gt t + . Gt G G Gt G G Bt Bt GBt GBt
+ 0O lt Gt t . + Gt Gt G Gt Gt G Bt Bt GBt GBt
+ 2 C P C C C + . . C - - CB CB B B
+ 2T Ct - Ct C C t + t - - - CBt CBt Bt Bt
+ 2O Ct - Ct C C t t + - - - CBt CBt Bt Bt
+ 3 [Q] p [Q] [Q] [Q] Q Q Q + . . [Q] [Q] Q Q
+ 3T [Qt] p [Qt][Q] [Q] Qt Qt Qt t + t [Qt][Qt] Qt Qt
+ 3O [Qt] p [Qt][Q] [Q] Qt Qt Qt t t + [Qt][Qt] Qt Qt
+ 4A lA G A T T GA GT GT GA GT GT + BA G GBA
+ 4O lA GBA A T T GA GT GT GA GT GT BA + GBA G
+ 6A CA PA CA C C A T tT PA P P C CBA + BA
+ 6O CA PBA CA C C A tT T PA P P CBA C BA +
Within the matrix,
+ "+" identifies entries where 'from' and 'to' are the same.
"-" means the transformation is not supported.
+ "." means nothing is necessary (a tRNS chunk can just be ignored).
+ "t" means the transformation is obtained by png_set_tRNS.
+ "A" means the transformation is obtained by png_set_add_alpha().
"X" means the transformation is obtained by png_set_expand().
"1" means the transformation is obtained by
- png_set_expand_gray_1_2_4_to_8
- "G" means the transformation is obtained by
- png_set_gray_to_rgb().
+ png_set_expand_gray_1_2_4_to_8() (and by png_set_expand()
+ if there is no transparency in the original or the final
+ format).
+ "C" means the transformation is obtained by png_set_gray_to_rgb().
+ "G" means the transformation is obtained by png_set_rgb_to_gray().
"P" means the transformation is obtained by
png_set_expand_palette_to_rgb().
+ "p" means the transformation is obtained by png_set_packing().
+ "Q" means the transformation is obtained by png_set_quantize().
"T" means the transformation is obtained by
png_set_tRNS_to_alpha().
+ "B" means the transformation is obtained by
+ png_set_background(), or png_strip_alpha().
-PNG can have files with 16 bits per channel. If you only can handle
-8 bits per channel, this will strip the pixels down to 8 bit.
-
- if (bit_depth == 16)
- png_set_strip_16(png_ptr);
-
-If, for some reason, you don't need the alpha channel on an image,
-and you want to remove it rather than combining it with the background
-(but the image author certainly had in mind that you *would* combine
-it with the background, so that's what you should probably do):
-
- if (color_type & PNG_COLOR_MASK_ALPHA)
- png_set_strip_alpha(png_ptr);
+When an entry has multiple transforms listed all are required to cause the
+right overall transformation. When two transforms are separated by a comma
+either will do the job. When transforms are enclosed in [] the transform should
+do the job but this is currently unimplemented - a different format will result
+if the suggested transformations are used.
In PNG files, the alpha channel in an image
is the level of opacity. If you need the alpha channel in an image to
@@ -1759,22 +2375,13 @@ images) is fully transparent, with
png_set_invert_alpha(png_ptr);
-The PNG format only supports pixels with postmultiplied alpha.
-If you want to replace the pixels, after reading them, with pixels
-that have premultiplied color samples, you can do this with
-
- png_set_premultiply_alpha(png_ptr);
-
-If you do this, any input with a tRNS chunk will be expanded to
-have an alpha channel.
-
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
they can, resulting in, for example, 8 pixels per byte for 1 bit
files. This code expands to 1 pixel per byte without changing the
values of the pixels:
if (bit_depth < 8)
- png_set_packing(png_ptr);
+ png_set_packing(png_ptr);
PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
stored in a PNG image have been "scaled" or "shifted" up to the next
@@ -1786,217 +2393,201 @@ image. This call reduces the pixels back down to the original bit depth:
png_color_8p sig_bit;
if (png_get_sBIT(png_ptr, info_ptr, &sig_bit))
- png_set_shift(png_ptr, sig_bit);
+ png_set_shift(png_ptr, sig_bit);
PNG files store 3-color pixels in red, green, blue order. This code
changes the storage of the pixels to blue, green, red:
if (color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- png_set_bgr(png_ptr);
+ png_set_bgr(png_ptr);
PNG files store RGB pixels packed into 3 or 6 bytes. This code expands them
into 4 or 8 bytes for windowing systems that need them in this format:
if (color_type == PNG_COLOR_TYPE_RGB)
- png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
+ png_set_filler(png_ptr, filler, PNG_FILLER_BEFORE);
-where "filler" is the 8 or 16-bit number to fill with, and the location is
-either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
-you want the filler before the RGB or after. This transformation
-does not affect images that already have full alpha channels. To add an
-opaque alpha channel, use filler=0xff or 0xffff and PNG_FILLER_AFTER which
-will generate RGBA pixels.
+where "filler" is the 8-bit or 16-bit number to fill with, and the location
+is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether
+you want the filler before the RGB or after. When filling an 8-bit pixel,
+the least significant 8 bits of the number are used, if a 16-bit number is
+supplied. This transformation does not affect images that already have full
+alpha channels. To add an opaque alpha channel, use filler=0xffff and
+PNG_FILLER_AFTER which will generate RGBA pixels.
Note that png_set_filler() does not change the color type. If you want
to do that, you can add a true alpha channel with
if (color_type == PNG_COLOR_TYPE_RGB ||
- color_type == PNG_COLOR_TYPE_GRAY)
- png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
+ color_type == PNG_COLOR_TYPE_GRAY)
+ png_set_add_alpha(png_ptr, filler, PNG_FILLER_AFTER);
where "filler" contains the alpha value to assign to each pixel.
-This function was added in libpng-1.2.7.
+The png_set_add_alpha() function was added in libpng-1.2.7.
If you are reading an image with an alpha channel, and you need the
data as ARGB instead of the normal PNG format RGBA:
if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- png_set_swap_alpha(png_ptr);
+ png_set_swap_alpha(png_ptr);
For some uses, you may want a grayscale image to be represented as
RGB. This code will do that conversion:
if (color_type == PNG_COLOR_TYPE_GRAY ||
color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- png_set_gray_to_rgb(png_ptr);
+ png_set_gray_to_rgb(png_ptr);
Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
with alpha.
if (color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- png_set_rgb_to_gray_fixed(png_ptr, error_action,
- int red_weight, int green_weight);
+ png_set_rgb_to_gray(png_ptr, error_action,
+ double red_weight, double green_weight);
error_action = 1: silently do the conversion
+
error_action = 2: issue a warning if the original
image has any pixel where
red != green or red != blue
+
error_action = 3: issue an error and abort the
conversion if the original
image has any pixel where
red != green or red != blue
- red_weight: weight of red component times 100000
- green_weight: weight of green component times 100000
+ red_weight: weight of red component
+
+ green_weight: weight of green component
If either weight is negative, default
- weights (21268, 71514) are used.
+ weights are used.
+
+In the corresponding fixed point API the red_weight and green_weight values are
+simply scaled by 100,000:
+
+ png_set_rgb_to_gray(png_ptr, error_action,
+ png_fixed_point red_weight,
+ png_fixed_point green_weight);
If you have set error_action = 1 or 2, you can
later check whether the image really was gray, after processing
the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
It will return a png_byte that is zero if the image was gray or
-1 if there were any non-gray pixels. bKGD and sBIT data
+1 if there were any non-gray pixels. Background and sBIT data
will be silently converted to grayscale, using the green channel
-data, regardless of the error_action setting.
+data for sBIT, regardless of the error_action setting.
-With red_weight+green_weight<=100000,
-the normalized graylevel is computed:
+The default values come from the PNG file cHRM chunk if present; otherwise, the
+defaults correspond to the ITU-R recommendation 709, and also the sRGB color
+space, as recommended in the Charles Poynton's Colour FAQ,
+Copyright (c) 2006-11-28 Charles Poynton, in section 9:
- int rw = red_weight * 65536;
- int gw = green_weight * 65536;
- int bw = 65536 - (rw + gw);
- gray = (rw*red + gw*green + bw*blue)/65536;
+<http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9>
-The default values approximate those recommended in the Charles
-Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
-Copyright (c) 1998-01-04 Charles Poynton <poynton at inforamp.net>
+ Y = 0.2126 * R + 0.7152 * G + 0.0722 * B
- Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
-
-Libpng approximates this with
+Previous versions of this document, 1998 through 2002, recommended a slightly
+different formula:
- Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
+ Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
-which can be expressed with integers as
+Libpng uses an integer approximation:
- Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ Y = (6968 * R + 23434 * G + 2366 * B)/32768
The calculation is done in a linear colorspace, if the image gamma
-is known.
+can be determined.
-If you have a grayscale and you are using png_set_expand_depth(),
-png_set_expand(), or png_set_gray_to_rgb to change to truecolor or to
-a higher bit-depth, you must either supply the background color as a gray
-value at the original file bit-depth (need_expand = 1) or else supply the
-background color as an RGB triplet at the final, expanded bit depth
-(need_expand = 0). Similarly, if you are reading a paletted image, you
-must either supply the background color as a palette index (need_expand = 1)
-or as an RGB triplet that may or may not be in the palette (need_expand = 0).
+The png_set_background() function has been described already; it tells libpng to
+composite images with alpha or simple transparency against the supplied
+background color. For compatibility with versions of libpng earlier than
+libpng-1.5.4 it is recommended that you call the function after reading the file
+header, even if you don't want to use the color in a bKGD chunk, if one exists.
+
+If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
+you may use this color, or supply another color more suitable for
+the current display (e.g., the background color from a web page). You
+need to tell libpng how the color is represented, both the format of the
+component values in the color (the number of bits) and the gamma encoding of the
+color. The function takes two arguments, background_gamma_mode and need_expand
+to convey this information; however, only two combinations are likely to be
+useful:
png_color_16 my_background;
png_color_16p image_background;
if (png_get_bKGD(png_ptr, info_ptr, &image_background))
- png_set_background(png_ptr, image_background,
- PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+ png_set_background(png_ptr, image_background,
+ PNG_BACKGROUND_GAMMA_FILE, 1/*needs to be expanded*/, 1);
else
- png_set_background(png_ptr, &my_background,
- PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
+ png_set_background(png_ptr, &my_background,
+ PNG_BACKGROUND_GAMMA_SCREEN, 0/*do not expand*/, 1);
+
+The second call was described above - my_background is in the format of the
+final, display, output produced by libpng. Because you now know the format of
+the PNG it is possible to avoid the need to choose either 8-bit or 16-bit
+output and to retain palette images (the palette colors will be modified
+appropriately and the tRNS chunk removed.) However, if you are doing this,
+take great care not to ask for transformations without checking first that
+they apply!
+
+In the first call the background color has the original bit depth and color type
+of the PNG file. So, for palette images the color is supplied as a palette
+index and for low bit greyscale images the color is a reduced bit value in
+image_background->gray.
+
+If you didn't call png_set_gamma() before reading the file header, for example
+if you need your code to remain compatible with older versions of libpng prior
+to libpng-1.5.4, this is the place to call it.
+
+Do not call it if you called png_set_alpha_mode(); doing so will damage the
+settings put in place by png_set_alpha_mode(). (If png_set_alpha_mode() is
+supported then you can certainly do png_set_gamma() before reading the PNG
+header.)
+
+This API unconditionally sets the screen and file gamma values, so it will
+override the value in the PNG file unless it is called before the PNG file
+reading starts. For this reason you must always call it with the PNG file
+value when you call it in this position:
+
+ if (png_get_gAMA(png_ptr, info_ptr, &file_gamma))
+ png_set_gamma(png_ptr, screen_gamma, file_gamma);
-The png_set_background() function tells libpng to composite images
-with alpha or simple transparency against the supplied background
-color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
-you may use this color, or supply another color more suitable for
-the current display (e.g., the background color from a web page). You
-need to tell libpng whether the color is in the gamma space of the
-display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
-(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
-that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
-know why anyone would use this, but it's here).
-
-To properly display PNG images on any kind of system, the application needs
-to know what the display gamma is. Ideally, the user will know this, and
-the application will allow them to set it. One method of allowing the user
-to set the display gamma separately for each system is to check for a
-SCREEN_GAMMA or DISPLAY_GAMMA environment variable, which will hopefully be
-correctly set.
-
-Note that display_gamma is the overall gamma correction required to produce
-pleasing results, which depends on the lighting conditions in the surrounding
-environment. In a dim or brightly lit room, no compensation other than
-the physical gamma exponent of the monitor is needed, while in a dark room
-a slightly smaller exponent is better.
-
- double gamma, screen_gamma;
-
- if (/* We have a user-defined screen
- gamma value */)
- {
- screen_gamma = user_defined_screen_gamma;
- }
- /* One way that applications can share the same
- screen gamma value */
- else if ((gamma_str = getenv("SCREEN_GAMMA"))
- != NULL)
- {
- screen_gamma = (double)atof(gamma_str);
- }
- /* If we don't have another value */
- else
- {
- screen_gamma = 2.2; /* A good guess for a
- PC monitor in a bright office or a dim room */
- screen_gamma = 2.0; /* A good guess for a
- PC monitor in a dark room */
- screen_gamma = 1.7 or 1.0; /* A good
- guess for Mac systems */
- }
-
-The png_set_gamma() function handles gamma transformations of the data.
-Pass both the file gamma and the current screen_gamma. If the file does
-not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.45455 is a good guess for GIF images on PCs). Note
-that file gammas are inverted from screen gammas. See the discussions
-on gamma in the PNG specification for an excellent description of what
-gamma is, and why all applications should support it. It is strongly
-recommended that PNG viewers support gamma correction.
-
- if (png_get_gAMA(png_ptr, info_ptr, &gamma))
- png_set_gamma(png_ptr, screen_gamma, gamma);
else
png_set_gamma(png_ptr, screen_gamma, 0.45455);
If you need to reduce an RGB file to a paletted file, or if a paletted
-file has more entries then will fit on your screen, png_set_dither()
-will do that. Note that this is a simple match dither that merely
+file has more entries than will fit on your screen, png_set_quantize()
+will do that. Note that this is a simple match quantization that merely
finds the closest color available. This should work fairly well with
-optimized palettes, and fairly badly with linear color cubes. If you
-pass a palette that is larger then maximum_colors, the file will
+optimized palettes, but fairly badly with linear color cubes. If you
+pass a palette that is larger than maximum_colors, the file will
reduce the number of colors in the palette so it will fit into
-maximum_colors. If there is a histogram, it will use it to make
+maximum_colors. If there is a histogram, libpng will use it to make
more intelligent choices when reducing the palette. If there is no
histogram, it may not do as good a job.
if (color_type & PNG_COLOR_MASK_COLOR)
{
if (png_get_valid(png_ptr, info_ptr,
- PNG_INFO_PLTE))
+ PNG_INFO_PLTE))
{
png_uint_16p histogram = NULL;
png_get_hIST(png_ptr, info_ptr,
- &histogram);
- png_set_dither(png_ptr, palette, num_palette,
+ &histogram);
+ png_set_quantize(png_ptr, palette, num_palette,
max_screen_colors, histogram, 1);
}
+
else
{
png_color std_color_cube[MAX_SCREEN_COLORS] =
{ ... colors ... };
- png_set_dither(png_ptr, std_color_cube,
+ png_set_quantize(png_ptr, std_color_cube,
MAX_SCREEN_COLORS, MAX_SCREEN_COLORS,
NULL,0);
}
@@ -2012,16 +2603,16 @@ zero):
This function can also be used to invert grayscale and gray-alpha images:
if (color_type == PNG_COLOR_TYPE_GRAY ||
- color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_invert_mono(png_ptr);
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
ie. most significant bits first). This code changes the storage to the
other way (little-endian, i.e. least significant bits first, the
way PCs store them):
if (bit_depth == 16)
- png_set_swap(png_ptr);
+ png_set_swap(png_ptr);
If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you
need to change the order the pixels are packed into bytes, you can use:
@@ -2034,15 +2625,36 @@ the existing ones meets your needs. This is done by setting a callback
with
png_set_read_user_transform_fn(png_ptr,
- read_transform_fn);
+ read_transform_fn);
You must supply the function
- void read_transform_fn(png_ptr ptr, row_info_ptr
- row_info, png_bytep data)
+ void read_transform_fn(png_structp png_ptr, png_row_infop
+ row_info, png_bytep data)
See pngtest.c for a working example. Your function will be called
-after all of the other transformations have been processed.
+after all of the other transformations have been processed. Take care with
+interlaced images if you do the interlace yourself - the width of the row is the
+width in 'row_info', not the overall image width.
+
+If supported, libpng provides two information routines that you can use to find
+where you are in processing the image:
+
+ png_get_current_pass_number(png_structp png_ptr);
+ png_get_current_row_number(png_structp png_ptr);
+
+Don't try using these outside a transform callback - firstly they are only
+supported if user transforms are supported, secondly they may well return
+unexpected results unless the row is actually being processed at the moment they
+are called.
+
+With interlaced
+images the value returned is the row in the input sub-image image. Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+
+The discussion of interlace handling above contains more information on how to
+use these values.
You can also set up a pointer to a user structure for use by your
callback function, and you can inform libpng that your transform
@@ -2050,7 +2662,7 @@ function will change the number of channels or bit depth with the
function
png_set_user_transform_info(png_ptr, user_ptr,
- user_depth, user_channels);
+ user_depth, user_channels);
The user's application, not libpng, is responsible for allocating and
freeing any memory required for the user structure.
@@ -2059,7 +2671,7 @@ You can retrieve the pointer via the function
png_get_user_transform_ptr(). For example:
voidp read_user_transform_ptr =
- png_get_user_transform_ptr(png_ptr);
+ png_get_user_transform_ptr(png_ptr);
The last thing to handle is interlacing; this is covered in detail below,
but you must call the function here if you want libpng to handle expansion
@@ -2069,13 +2681,16 @@ of the interlaced image.
After setting the transformations, libpng can update your png_info
structure to reflect any transformations you've requested with this
-call. This is most useful to update the info structure's rowbytes
-field so you can use it to allocate your image memory. This function
-will also update your palette with the correct screen_gamma and
-background if these have been given with the calls above.
+call.
png_read_update_info(png_ptr, info_ptr);
+This is most useful to update the info structure's rowbytes
+field so you can use it to allocate your image memory. This function
+will also update your palette with the correct screen_gamma and
+background if these have been given with the calls above. You may
+only call png_read_update_info() once with a particular info_ptr.
+
After you call png_read_update_info(), you can allocate any
memory you need to hold the image. The row data is simply
raw byte data for all forms of images. As the actual allocation
@@ -2084,6 +2699,25 @@ are allocating one large chunk, you will need to build an
array of pointers to each row, as it will be needed for some
of the functions below.
+Be sure that your platform can allocate the buffer that you'll need.
+libpng internally checks for oversize width, but you'll need to
+do your own check for number_of_rows*width*pixel_size if you are using
+a multiple-row buffer:
+
+ /* Guard against integer overflow */
+ if (number_of_rows > PNG_SIZE_MAX/(width*pixel_size)) {
+ png_error(png_ptr,"image_data buffer would be too large");
+ }
+
+Remember: Before you call png_read_update_info(), the png_get_*()
+functions return the values corresponding to the original PNG image.
+After you call png_read_update_info the values refer to the image
+that libpng will output. Consequently you must call all the png_set_
+functions before you call png_read_update_info(). This is particularly
+important for png_set_interlace_handling() - if you are going to call
+png_read_update_info() you must call png_set_interlace_handling() before
+it unless you want to receive interlaced output.
+
.SS Reading image data
After you've allocated memory, you can read the image data.
@@ -2093,9 +2727,10 @@ call png_read_image() and libpng will read in all the image data
and put it in the memory area supplied. You will need to pass in
an array of pointers to each row.
-This function automatically handles interlacing, so you don't need
-to call png_set_interlace_handling() or call this function multiple
-times, or any of that other stuff necessary with png_read_rows().
+This function automatically handles interlacing, so you don't
+need to call png_set_interlace_handling() (unless you call
+png_read_update_info()) or call this function multiple times, or any
+of that other stuff necessary with png_read_rows().
png_read_image(png_ptr, row_pointers);
@@ -2110,7 +2745,7 @@ use png_read_rows() instead. If there is no interlacing (check
interlace_type == PNG_INTERLACE_NONE), this is simple:
png_read_rows(png_ptr, row_pointers, NULL,
- number_of_rows);
+ number_of_rows);
where row_pointers is the same as in the png_read_image() call.
@@ -2122,13 +2757,15 @@ a single row_pointer instead of an array of row_pointers:
If the file is interlaced (interlace_type != 0 in the IHDR chunk), things
get somewhat harder. The only current (PNG Specification version 1.2)
-interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7)
-is a somewhat complicated 2D interlace scheme, known as Adam7, that
+interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7);
+a somewhat complicated 2D interlace scheme, known as Adam7, that
breaks down an image into seven smaller images of varying size, based
-on an 8x8 grid.
+on an 8x8 grid. This number is defined (from libpng 1.5) as
+PNG_INTERLACE_ADAM7_PASSES in png.h
libpng can fill out those images or it can give them to you "as is".
-If you want them filled out, there are two ways to do that. The one
+It is almost always better to have libpng handle the interlacing for you.
+If you want the images filled out, there are two ways to do that. The one
mentioned in the PNG specification is to expand each pixel to cover
those pixels that have not been read yet (the "rectangle" method).
This results in a blocky image for the first pass, which gradually
@@ -2138,37 +2775,20 @@ rest of the image remaining whatever colors they were initialized to
before the start of the read. The first method usually looks better,
but tends to be slower, as there are more pixels to put in the rows.
-If you don't want libpng to handle the interlacing details, just call
-png_read_rows() seven times to read in all seven images. Each of the
-images is a valid image by itself, or they can all be combined on an
-8x8 grid to form a single image (although if you intend to combine them
-you would be far better off using the libpng interlace handling).
-
-The first pass will return an image 1/8 as wide as the entire image
-(every 8th column starting in column 0) and 1/8 as high as the original
-(every 8th row starting in row 0), the second will be 1/8 as wide
-(starting in column 4) and 1/8 as high (also starting in row 0). The
-third pass will be 1/4 as wide (every 4th pixel starting in column 0) and
-1/8 as high (every 8th row starting in row 4), and the fourth pass will
-be 1/4 as wide and 1/4 as high (every 4th column starting in column 2,
-and every 4th row starting in row 0). The fifth pass will return an
-image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2),
-while the sixth pass will be 1/2 as wide and 1/2 as high as the original
-(starting in column 1 and row 0). The seventh and final pass will be as
-wide as the original, and 1/2 as high, containing all of the odd
-numbered scanlines. Phew!
-
-If you want libpng to expand the images, call this before calling
-png_start_read_image() or png_read_update_info():
+If, as is likely, you want libpng to expand the images, call this before
+calling png_start_read_image() or png_read_update_info():
if (interlace_type == PNG_INTERLACE_ADAM7)
- number_of_passes
+ number_of_passes
= png_set_interlace_handling(png_ptr);
-This will return the number of passes needed. Currently, this
-is seven, but may change if another interlace type is added.
-This function can be called even if the file is not interlaced,
-where it will return one pass.
+This will return the number of passes needed. Currently, this is seven,
+but may change if another interlace type is added. This function can be
+called even if the file is not interlaced, where it will return one pass.
+You then need to read the whole image 'number_of_passes' times. Each time
+will distribute the pixels from the current pass to the correct place in
+the output image, so you need to supply the same rows to png_read_rows in
+each pass.
If you are not going to display the image after each pass, but are
going to wait until the entire image is read in, use the sparkle
@@ -2177,7 +2797,8 @@ is exactly the same. If you are planning on displaying the image
after each pass, the "rectangle" effect is generally considered the
better looking one.
-If you only want the "sparkle" effect, just call png_read_rows() as
+If you only want the "sparkle" effect, just call png_read_row() or
+png_read_rows() as
normal, with the third parameter NULL. Make sure you make pass over
the image number_of_passes times, and you don't change the data in the
rows between calls. You can change the locations of the data, just
@@ -2185,35 +2806,162 @@ not the data. Each pass only writes the pixels appropriate for that
pass, and assumes the data from previous passes is still valid.
png_read_rows(png_ptr, row_pointers, NULL,
- number_of_rows);
+ number_of_rows);
+ or
+ png_read_row(png_ptr, row_pointers, NULL);
If you only want the first effect (the rectangles), do the same as
before except pass the row buffer in the third parameter, and leave
the second parameter NULL.
png_read_rows(png_ptr, NULL, row_pointers,
- number_of_rows);
+ number_of_rows);
+ or
+ png_read_row(png_ptr, NULL, row_pointers);
+
+If you don't want libpng to handle the interlacing details, just call
+png_read_rows() PNG_INTERLACE_ADAM7_PASSES times to read in all the images.
+Each of the images is a valid image by itself; however, you will almost
+certainly need to distribute the pixels from each sub-image to the
+correct place. This is where everything gets very tricky.
+
+If you want to retrieve the separate images you must pass the correct
+number of rows to each successive call of png_read_rows(). The calculation
+gets pretty complicated for small images, where some sub-images may
+not even exist because either their width or height ends up zero.
+libpng provides two macros to help you in 1.5 and later versions:
+
+ png_uint_32 width = PNG_PASS_COLS(image_width, pass_number);
+ png_uint_32 height = PNG_PASS_ROWS(image_height, pass_number);
+
+Respectively these tell you the width and height of the sub-image
+corresponding to the numbered pass. 'pass' is in in the range 0 to 6 -
+this can be confusing because the specification refers to the same passes
+as 1 to 7! Be careful, you must check both the width and height before
+calling png_read_rows() and not call it for that pass if either is zero.
+
+You can, of course, read each sub-image row by row. If you want to
+produce optimal code to make a pixel-by-pixel transformation of an
+interlaced image this is the best approach; read each row of each pass,
+transform it, and write it out to a new interlaced image.
+
+If you want to de-interlace the image yourself libpng provides further
+macros to help that tell you where to place the pixels in the output image.
+Because the interlacing scheme is rectangular - sub-image pixels are always
+arranged on a rectangular grid - all you need to know for each pass is the
+starting column and row in the output image of the first pixel plus the
+spacing between each pixel. As of libpng 1.5 there are four macros to
+retrieve this information:
+
+ png_uint_32 x = PNG_PASS_START_COL(pass);
+ png_uint_32 y = PNG_PASS_START_ROW(pass);
+ png_uint_32 xStep = 1U << PNG_PASS_COL_SHIFT(pass);
+ png_uint_32 yStep = 1U << PNG_PASS_ROW_SHIFT(pass);
+
+These allow you to write the obvious loop:
+
+ png_uint_32 input_y = 0;
+ png_uint_32 output_y = PNG_PASS_START_ROW(pass);
+
+ while (output_y < output_image_height)
+ {
+ png_uint_32 input_x = 0;
+ png_uint_32 output_x = PNG_PASS_START_COL(pass);
+
+ while (output_x < output_image_width)
+ {
+ image[output_y][output_x] =
+ subimage[pass][input_y][input_x++];
+
+ output_x += xStep;
+ }
+
+ ++input_y;
+ output_y += yStep;
+ }
+
+Notice that the steps between successive output rows and columns are
+returned as shifts. This is possible because the pixels in the subimages
+are always a power of 2 apart - 1, 2, 4 or 8 pixels - in the original
+image. In practice you may need to directly calculate the output coordinate
+given an input coordinate. libpng provides two further macros for this
+purpose:
+
+ png_uint_32 output_x = PNG_COL_FROM_PASS_COL(input_x, pass);
+ png_uint_32 output_y = PNG_ROW_FROM_PASS_ROW(input_y, pass);
+
+Finally a pair of macros are provided to tell you if a particular image
+row or column appears in a given pass:
+
+ int col_in_pass = PNG_COL_IN_INTERLACE_PASS(output_x, pass);
+ int row_in_pass = PNG_ROW_IN_INTERLACE_PASS(output_y, pass);
+
+Bear in mind that you will probably also need to check the width and height
+of the pass in addition to the above to be sure the pass even exists!
+
+With any luck you are convinced by now that you don't want to do your own
+interlace handling. In reality normally the only good reason for doing this
+is if you are processing PNG files on a pixel-by-pixel basis and don't want
+to load the whole file into memory when it is interlaced.
+
+libpng includes a test program, pngvalid, that illustrates reading and
+writing of interlaced images. If you can't get interlacing to work in your
+code and don't want to leave it to libpng (the recommended approach), see
+how pngvalid.c does it.
.SS Finishing a sequential read
After you are finished reading the image through the
-low-level interface, you can finish reading the file. If you are
-interested in comments or time, which may be stored either before or
-after the image data, you should pass the separate png_info struct if
-you want to keep the comments from before and after the image
-separate. If you are not interested, you can pass NULL.
+low-level interface, you can finish reading the file.
+
+If you want to use a different crc action for handling CRC errors in
+chunks after the image data, you can call png_set_crc_action()
+again at this point.
+
+If you are interested in comments or time, which may be stored either
+before or after the image data, you should pass the separate png_info
+struct if you want to keep the comments from before and after the image
+separate.
+
+ png_infop end_info = png_create_info_struct(png_ptr);
+
+ if (!end_info)
+ {
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return ERROR;
+ }
png_read_end(png_ptr, end_info);
+If you are not interested, you should still call png_read_end()
+but you can pass NULL, avoiding the need to create an end_info structure.
+If you do this, libpng will not process any chunks after IDAT other than
+skipping over them and perhaps (depending on whether you have called
+png_set_crc_action) checking their CRCs while looking for the IEND chunk.
+
+ png_read_end(png_ptr, (png_infop)NULL);
+
+If you don't call png_read_end(), then your file pointer will be
+left pointing to the first chunk after the last IDAT, which is probably
+not what you want if you expect to read something beyond the end of
+the PNG datastream.
+
When you are done, you can free all memory allocated by libpng like this:
png_destroy_read_struct(&png_ptr, &info_ptr,
&end_info);
+or, if you didn't create an end_info structure,
+
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+
It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, seq)
+
mask - identifies data to be freed, a mask
containing the bitwise OR of one or
more of
@@ -2223,30 +2971,33 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
+
seq - sequence number of item to be freed
- (-1 for all items)
+ (\-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those cases do nothing.
The "seq" parameter is ignored if only one item of the selected data
-type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+type, such as PLTE, is allowed. If "seq" is not \-1, and multiple items
are allowed for the data type identified in the mask, such as text or
sPLT, only the n'th item in the structure is freed, where n is "seq".
The default behavior is only to free data that was allocated internally
by libpng. This can be changed, so that libpng will not free the data,
or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
png_data_freer(png_ptr, info_ptr, freer, mask)
- mask - which data elements are affected
- same choices as in png_free_data()
+
freer - one of
PNG_DESTROY_WILL_FREE_DATA
PNG_SET_WILL_FREE_DATA
PNG_USER_WILL_FREE_DATA
+ mask - which data elements are affected
+ same choices as in png_free_data()
+
This function only affects data that has already been allocated.
You can call this function after reading the PNG data but before calling
any png_set_*() functions, to control whether the user or the png_set_*()
@@ -2256,7 +3007,7 @@ or png_destroy_*() is supposed to free the data. When the user assumes
responsibility for libpng-allocated data, the application must use
png_free() to free it, and when the user transfers responsibility to libpng
for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
If you allocated your row_pointers in a single block, as suggested above in
the description of the high level read interface, you must not transfer
@@ -2275,12 +3026,14 @@ it frees. If you need to turn the flag off for a chunk that was freed by
your application instead of by libpng, you can use
png_set_invalid(png_ptr, info_ptr, mask);
+
mask - identifies the chunks to be made invalid,
containing the bitwise OR of one or
more of
PNG_INFO_gAMA, PNG_INFO_sBIT,
PNG_INFO_cHRM, PNG_INFO_PLTE,
PNG_INFO_tRNS, PNG_INFO_bKGD,
+ PNG_INFO_eXIf,
PNG_INFO_hIST, PNG_INFO_pHYs,
PNG_INFO_oFFs, PNG_INFO_tIME,
PNG_INFO_pCAL, PNG_INFO_sRGB,
@@ -2291,7 +3044,7 @@ For a more compact example of reading a PNG image, see the file example.c.
.SS Reading PNG files progressively
-The progressive reader is slightly different then the non-progressive
+The progressive reader is slightly different from the non-progressive
reader. Instead of calling png_read_info(), png_read_rows(), and
png_read_end(), you make one call to png_process_data(), which calls
callbacks when it has the info, a row, or the end of the image. You
@@ -2314,21 +3067,24 @@ png_infop info_ptr;
png_ptr = png_create_read_struct
(PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
user_error_fn, user_warning_fn);
+
if (!png_ptr)
- return (ERROR);
+ return ERROR;
+
info_ptr = png_create_info_struct(png_ptr);
+
if (!info_ptr)
{
- png_destroy_read_struct(&png_ptr, (png_infopp)NULL,
- (png_infopp)NULL);
- return (ERROR);
+ png_destroy_read_struct(&png_ptr,
+ (png_infopp)NULL, (png_infopp)NULL);
+ return ERROR;
}
if (setjmp(png_jmpbuf(png_ptr)))
{
- png_destroy_read_struct(&png_ptr, &info_ptr,
- (png_infopp)NULL);
- return (ERROR);
+ png_destroy_read_struct(&png_ptr, &info_ptr,
+ (png_infopp)NULL);
+ return ERROR;
}
/* This one's new. You can provide functions
@@ -2360,9 +3116,9 @@ png_infop info_ptr;
{
if (setjmp(png_jmpbuf(png_ptr)))
{
- png_destroy_read_struct(&png_ptr, &info_ptr,
+ png_destroy_read_struct(&png_ptr, &info_ptr,
(png_infopp)NULL);
- return (ERROR);
+ return ERROR;
}
/* This one's new also. Simply give it a chunk
@@ -2372,13 +3128,19 @@ png_infop info_ptr;
64K. The library seems to run fine with sizes
of 4K. Although you can give it much less if
necessary (I assume you can give it chunks of
- 1 byte, I haven't tried less then 256 bytes
+ 1 byte, I haven't tried less than 256 bytes
yet). When this function returns, you may
want to display any rows that were generated
in the row callback if you don't already do
so there.
*/
png_process_data(png_ptr, info_ptr, buffer, length);
+
+ /* At this point you can call png_process_data_skip if
+ you want to handle data the library will skip yourself;
+ it simply returns the number of bytes to skip (and stops
+ libpng skipping that number of bytes on the next
+ png_process_data call).
return 0;
}
@@ -2399,6 +3161,19 @@ png_infop info_ptr;
any). You may start getting rows before
png_process_data() returns, so this is your
last chance to prepare for that.
+
+ This is where you turn on interlace handling,
+ assuming you don't want to do it yourself.
+
+ If you need to you can stop the processing of
+ your original input data at this point by calling
+ png_process_data_pause. This returns the number
+ of unprocessed bytes from the last png_process_data
+ call - it is up to you to ensure that the next call
+ sees these bytes again. If you don't want to bother
+ with this you can get libpng to cache the unread
+ bytes by setting the 'save' parameter (see png.h) but
+ then libpng will have to copy the data internally.
*/
}
@@ -2419,20 +3194,28 @@ png_infop info_ptr;
supplying them because it may make your life
easier.
- For the non-NULL rows of interlaced images,
+ If you did not turn on interlace handling then
+ the callback is called for each row of each
+ sub-image when the image is interlaced. In this
+ case 'row_num' is the row in the sub-image, not
+ the row in the output image as it is in all other
+ cases.
+
+ For the non-NULL rows of interlaced images when
+ you have switched on libpng interlace handling,
you must call png_progressive_combine_row()
passing in the row and the old row. You can
call this function for NULL rows (it will just
return) and for non-interlaced images (it just
does the memcpy for you) if it will make the
code easier. Thus, you can just do this for
- all cases:
+ all cases if you switch on interlace handling;
*/
png_progressive_combine_row(png_ptr, old_row,
new_row);
- /* where old_row is what was displayed for
+ /* where old_row is what was displayed
previously for the row. Note that the first
pass (pass == 0, really) will completely cover
the old row, so the rows do not have to be
@@ -2440,6 +3223,9 @@ png_infop info_ptr;
for interlaced images), you will have to pass
the current row, and the function will combine
the old row and the new row.
+
+ You can also call png_process_data_pause in this
+ callback - see above.
*/
}
@@ -2474,10 +3260,9 @@ using the standard I/O functions, you will need to replace them with
custom writing functions. See the discussion under Customizing libpng.
FILE *fp = fopen(file_name, "wb");
+
if (!fp)
- {
- return (ERROR);
- }
+ return ERROR;
Next, png_struct and png_info need to be allocated and initialized.
As these can be both relatively large, you may not want to store these
@@ -2490,15 +3275,16 @@ both "png_ptr"; you can call them anything you like, such as
png_structp png_ptr = png_create_write_struct
(PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
user_error_fn, user_warning_fn);
+
if (!png_ptr)
- return (ERROR);
+ return ERROR;
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_write_struct(&png_ptr,
- (png_infopp)NULL);
- return (ERROR);
+ (png_infopp)NULL);
+ return ERROR;
}
If you want to use your own memory allocation routines,
@@ -2523,17 +3309,35 @@ section below for more information on the libpng error handling.
if (setjmp(png_jmpbuf(png_ptr)))
{
- png_destroy_write_struct(&png_ptr, &info_ptr);
+ png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(fp);
- return (ERROR);
+ return ERROR;
}
...
return;
If you would rather avoid the complexity of setjmp/longjmp issues,
-you can compile libpng with PNG_SETJMP_NOT_SUPPORTED, in which case
+you can compile libpng with PNG_NO_SETJMP, in which case
errors will result in a call to PNG_ABORT() which defaults to abort().
+You can #define PNG_ABORT() to a function that does something
+more useful than abort(), as long as your function does not
+return.
+
+Checking for invalid palette index on write was added at libpng
+1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error. This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
+
+ png_set_check_for_invalid_index(png_ptr, 0);
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are written as-is by the encoder, resulting in an
+invalid PNG datastream as output. In this case the application is
+responsible for ensuring that the pixel indexes are in range when it writes
+a PLTE chunk with fewer entries than the bit depth would allow.
+
Now you need to set up the output code. The default for libpng is to
use the C function fwrite(). If you use this, you will need to pass a
valid FILE * in the function png_init_io(). Be sure that the file is
@@ -2558,7 +3362,7 @@ called after each row has been written, which you can use to control
a progress meter or the like. It's demonstrated in pngtest.c.
You must supply a function
- void write_row_callback(png_ptr, png_uint_32 row,
+ void write_row_callback(png_structp png_ptr, png_uint_32 row,
int pass);
{
/* put your code here */
@@ -2570,6 +3374,20 @@ To inform libpng about your function, use
png_set_write_status_fn(png_ptr, write_row_callback);
+When this function is called the row has already been completely processed and
+it has also been written out. The 'row' and 'pass' refer to the next row to be
+handled. For the
+non-interlaced case the row that was just handled is simply one less than the
+passed in row number, and pass will always be 0. For the interlaced case the
+same applies unless the row value is 0, in which case the row just handled was
+the last one from one of the preceding passes. Because interlacing may skip a
+pass you cannot be sure that the preceding pass is just 'pass\-1', if you really
+need to know what the last pass is record (row,pass) from the callback and use
+the last recorded value each time.
+
+As with the user transform you can find the output row using the
+PNG_ROW_FROM_PASS_ROW macro.
+
You now have the option of modifying how the compression library will
run. The following functions are mainly for testing, but may be useful
in some cases, like if you need to write PNG files extremely fast and
@@ -2589,20 +3407,20 @@ filter types.
/* turn on or off filtering, and/or choose
specific filters. You can use either a single
PNG_FILTER_VALUE_NAME or the bitwise OR of one
- or more PNG_FILTER_NAME masks. */
+ or more PNG_FILTER_NAME masks.
+ */
png_set_filter(png_ptr, 0,
PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
PNG_FILTER_UP | PNG_FILTER_VALUE_UP |
PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG |
PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
- PNG_ALL_FILTERS);
+ PNG_ALL_FILTERS | PNG_FAST_FILTERS);
-If an application
-wants to start and stop using particular filters during compression,
-it should start out with all of the filters (to ensure that the previous
-row of pixels will be stored in case it's needed later), and then add
-and remove them after the start of compression.
+If an application wants to start and stop using particular filters during
+compression, it should start out with all of the filters (to ensure that
+the previous row of pixels will be stored in case it's needed later),
+and then add and remove them after the start of compression.
If you are writing a PNG datastream that is to be embedded in a MNG
datastream, the second parameter can be either 0 or 64.
@@ -2614,11 +3432,13 @@ which changes how much time zlib spends on trying to compress the image
data. See the Compression Library (zlib.h and algorithm.txt, distributed
with zlib) for details on the compression levels.
- /* set the zlib compression level */
+ #include zlib.h
+
+ /* Set the zlib compression level */
png_set_compression_level(png_ptr,
Z_BEST_COMPRESSION);
- /* set other zlib parameters */
+ /* Set other zlib parameters for compressing IDAT */
png_set_compression_mem_level(png_ptr, 8);
png_set_compression_strategy(png_ptr,
Z_DEFAULT_STRATEGY);
@@ -2626,7 +3446,15 @@ with zlib) for details on the compression levels.
png_set_compression_method(png_ptr, 8);
png_set_compression_buffer_size(png_ptr, 8192)
-extern PNG_EXPORT(void,png_set_zbuf_size)
+ /* Set zlib parameters for text compression
+ * If you don't call these, the parameters
+ * fall back on those defined for IDAT chunks
+ */
+ png_set_text_compression_mem_level(png_ptr, 8);
+ png_set_text_compression_strategy(png_ptr,
+ Z_DEFAULT_STRATEGY);
+ png_set_text_compression_window_bits(png_ptr, 15);
+ png_set_text_compression_method(png_ptr, 8);
.SS Setting the contents of info for output
@@ -2646,16 +3474,20 @@ Some of the more important parts of the png_info are:
png_set_IHDR(png_ptr, info_ptr, width, height,
bit_depth, color_type, interlace_type,
compression_type, filter_method)
+
width - holds the width of the image
in pixels (up to 2^31).
+
height - holds the height of the image
in pixels (up to 2^31).
+
bit_depth - holds the bit depth of one of the
image channels.
(valid values are 1, 2, 4, 8, 16
and depend also on the
color_type. See also significant
bits (sBIT) below).
+
color_type - describes which color/alpha
channels are present.
PNG_COLOR_TYPE_GRAY
@@ -2675,8 +3507,10 @@ Some of the more important parts of the png_info are:
interlace_type - PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7
+
compression_type - (must be
PNG_COMPRESSION_TYPE_DEFAULT)
+
filter_method - (must be PNG_FILTER_TYPE_DEFAULT
or, if you are writing a PNG to
be embedded in a MNG datastream,
@@ -2694,15 +3528,45 @@ width, height, bit_depth, and color_type must be the same in each call.
png_set_PLTE(png_ptr, info_ptr, palette,
num_palette);
+
palette - the palette for the file
(array of png_color)
num_palette - number of entries in the palette
- png_set_gAMA(png_ptr, info_ptr, gamma);
- gamma - the gamma the image was created
- at (PNG_INFO_gAMA)
+
+ png_set_gAMA(png_ptr, info_ptr, file_gamma);
+ png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+
+ file_gamma - the gamma at which the image was
+ created (PNG_INFO_gAMA)
+
+ int_file_gamma - 100,000 times the gamma at which
+ the image was created
+
+ png_set_cHRM(png_ptr, info_ptr, white_x, white_y, red_x, red_y,
+ green_x, green_y, blue_x, blue_y)
+ png_set_cHRM_XYZ(png_ptr, info_ptr, red_X, red_Y, red_Z, green_X,
+ green_Y, green_Z, blue_X, blue_Y, blue_Z)
+ png_set_cHRM_fixed(png_ptr, info_ptr, int_white_x, int_white_y,
+ int_red_x, int_red_y, int_green_x, int_green_y,
+ int_blue_x, int_blue_y)
+ png_set_cHRM_XYZ_fixed(png_ptr, info_ptr, int_red_X, int_red_Y,
+ int_red_Z, int_green_X, int_green_Y, int_green_Z,
+ int_blue_X, int_blue_Y, int_blue_Z)
+
+ {white,red,green,blue}_{x,y}
+ A color space encoding specified using the chromaticities
+ of the end points and the white point.
+
+ {red,green,blue}_{X,Y,Z}
+ A color space encoding specified using the encoding end
+ points - the CIE tristimulus specification of the intended
+ color of the red, green and blue channels in the PNG RGB
+ data. The white point is simply the sum of the three end
+ points.
png_set_sRGB(png_ptr, info_ptr, srgb_intent);
+
srgb_intent - the rendering intent
(PNG_INFO_sRGB) The presence of
the sRGB chunk means that the pixel
@@ -2722,6 +3586,7 @@ width, height, bit_depth, and color_type must be the same in each call.
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
srgb_intent);
+
srgb_intent - the rendering intent
(PNG_INFO_sRGB) The presence of the
sRGB chunk means that the pixel
@@ -2732,49 +3597,67 @@ width, height, bit_depth, and color_type must be the same in each call.
written.
png_set_iCCP(png_ptr, info_ptr, name, compression_type,
- profile, proflen);
- name - The profile name.
- compression - The compression type; always
- PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
- You may give NULL to this argument to
- ignore it.
- profile - International Color Consortium color
- profile data. May contain NULs.
- proflen - length of profile data in bytes.
+ profile, proflen);
+
+ name - The profile name.
+
+ compression_type - The compression type; always
+ PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
+ You may give NULL to this argument to
+ ignore it.
+
+ profile - International Color Consortium color
+ profile data. May contain NULs.
+
+ proflen - length of profile data in bytes.
png_set_sBIT(png_ptr, info_ptr, sig_bit);
+
sig_bit - the number of significant bits for
(PNG_INFO_sBIT) each of the gray, red,
green, and blue channels, whichever are
appropriate for the given color type
(png_color_16)
- png_set_tRNS(png_ptr, info_ptr, trans, num_trans,
- trans_values);
- trans - array of transparent
+ png_set_tRNS(png_ptr, info_ptr, trans_alpha,
+ num_trans, trans_color);
+
+ trans_alpha - array of alpha (transparency)
entries for palette (PNG_INFO_tRNS)
- trans_values - graylevel or color sample values
+
+ num_trans - number of transparent entries
+ (PNG_INFO_tRNS)
+
+ trans_color - graylevel or color sample values
(in order red, green, blue) of the
single transparent color for
non-paletted images (PNG_INFO_tRNS)
- num_trans - number of transparent entries
- (PNG_INFO_tRNS)
+
+ png_set_eXIf_1(png_ptr, info_ptr, num_exif, exif);
+
+ exif - Exif profile (array of
+ png_byte) (PNG_INFO_eXIf)
png_set_hIST(png_ptr, info_ptr, hist);
- (PNG_INFO_hIST)
+
hist - histogram of palette (array of
- png_uint_16)
+ png_uint_16) (PNG_INFO_hIST)
png_set_tIME(png_ptr, info_ptr, mod_time);
+
mod_time - time image was last modified
(PNG_VALID_tIME)
png_set_bKGD(png_ptr, info_ptr, background);
- background - background color (PNG_VALID_bKGD)
+
+ background - background color (of type
+ png_color_16p) (PNG_VALID_bKGD)
png_set_text(png_ptr, info_ptr, text_ptr, num_text);
+
text_ptr - array of png_text holding image
comments
+
text_ptr[i].compression - type of compression used
on "text" PNG_TEXT_COMPRESSION_NONE
PNG_TEXT_COMPRESSION_zTXt
@@ -2792,14 +3675,21 @@ width, height, bit_depth, and color_type must be the same in each call.
empty for unknown).
text_ptr[i].translated_keyword - keyword in UTF-8 (NULL
or empty for unknown).
+
Note that the itxt_length, lang, and lang_key
- members of the text_ptr structure only exist
- when the library is built with iTXt chunk support.
+ members of the text_ptr structure only exist when the
+ library is built with iTXt chunk support. Prior to
+ libpng-1.4.0 the library was built by default without
+ iTXt support. Also note that when iTXt is supported,
+ they contain NULL pointers when the "compression"
+ field contains PNG_TEXT_COMPRESSION_NONE or
+ PNG_TEXT_COMPRESSION_zTXt.
num_text - number of comments
png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
num_spalettes);
+
palette_ptr - array of png_sPLT_struct structures
to be added to the list of palettes
in the info structure.
@@ -2808,35 +3698,49 @@ width, height, bit_depth, and color_type must be the same in each call.
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
unit_type);
+
offset_x - positive offset from the left
edge of the screen
+
offset_y - positive offset from the top
edge of the screen
+
unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
png_set_pHYs(png_ptr, info_ptr, res_x, res_y,
unit_type);
+
res_x - pixels/unit physical resolution
in x direction
+
res_y - pixels/unit physical resolution
in y direction
+
unit_type - PNG_RESOLUTION_UNKNOWN,
PNG_RESOLUTION_METER
png_set_sCAL(png_ptr, info_ptr, unit, width, height)
+
unit - physical scale units (an integer)
+
width - width of a pixel in physical scale units
+
height - height of a pixel in physical scale units
(width and height are doubles)
png_set_sCAL_s(png_ptr, info_ptr, unit, width, height)
+
unit - physical scale units (an integer)
+
width - width of a pixel in physical scale units
+ expressed as a string
+
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
num_unknowns)
+
unknowns - array of png_unknown_chunk
structures holding unknown chunks
unknowns[i].name - name of unknown chunk
@@ -2871,25 +3775,34 @@ Because tEXt and zTXt chunks don't have a language field, if you
specify PNG_TEXT_COMPRESSION_NONE or PNG_TEXT_COMPRESSION_zTXt
any language code or translated keyword will not be written out.
-Until text gets around 1000 bytes, it is not worth compressing it.
+Until text gets around a few hundred bytes, it is not worth compressing it.
After the text has been written out to the file, the compression type
is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR,
so that it isn't written out again at the end (in case you are calling
-png_write_end() with the same struct.
+png_write_end() with the same struct).
The keywords that are given in the PNG Specification are:
Title Short (one line) title or
caption for image
+
Author Name of image's creator
+
Description Description of image (possibly long)
+
Copyright Copyright notice
+
Creation Time Time of original image creation
(usually RFC 1123 format, see below)
+
Software Software used to create the image
+
Disclaimer Legal disclaimer
+
Warning Warning of nature of content
+
Source Device used to create the image
+
Comment Miscellaneous comment; conversion
from other image format
@@ -2933,18 +3846,53 @@ tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
although this isn't a requirement. Unlike the tIME chunk, the
"Creation Time" tEXt chunk is not expected to be automatically changed
by the software. To facilitate the use of RFC 1123 dates, a function
-png_convert_to_rfc1123(png_timep) is provided to convert from PNG
-time to an RFC 1123 format string.
+png_convert_to_rfc1123_buffer(buffer, png_timep) is provided to
+convert from PNG time to an RFC 1123 format string. The caller must provide
+a writeable buffer of at least 29 bytes.
.SS Writing unknown chunks
-You can use the png_set_unknown_chunks function to queue up chunks
-for writing. You give it a chunk name, raw data, and a size; that's
-all there is to it. The chunks will be written by the next following
-png_write_info_before_PLTE, png_write_info, or png_write_end function.
-Any chunks previously read into the info structure's unknown-chunk
-list will also be written out in a sequence that satisfies the PNG
-specification's ordering rules.
+You can use the png_set_unknown_chunks function to queue up private chunks
+for writing. You give it a chunk name, location, raw data, and a size. You
+also must use png_set_keep_unknown_chunks() to ensure that libpng will
+handle them. That's all there is to it. The chunks will be written by the
+next following png_write_info_before_PLTE, png_write_info, or png_write_end
+function, depending upon the specified location. Any chunks previously
+read into the info structure's unknown-chunk list will also be written out
+in a sequence that satisfies the PNG specification's ordering rules.
+
+Here is an example of writing two private chunks, prVt and miNE:
+
+ #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+ /* Set unknown chunk data */
+ png_unknown_chunk unk_chunk[2];
+ strcpy((char *) unk_chunk[0].name, "prVt";
+ unk_chunk[0].data = (unsigned char *) "PRIVATE DATA";
+ unk_chunk[0].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[0].location = PNG_HAVE_IHDR;
+ strcpy((char *) unk_chunk[1].name, "miNE";
+ unk_chunk[1].data = (unsigned char *) "MY CHUNK DATA";
+ unk_chunk[1].size = strlen(unk_chunk[0].data)+1;
+ unk_chunk[1].location = PNG_AFTER_IDAT;
+ png_set_unknown_chunks(write_ptr, write_info_ptr,
+ unk_chunk, 2);
+ /* Needed because miNE is not safe-to-copy */
+ png_set_keep_unknown_chunks(png, PNG_HANDLE_CHUNK_ALWAYS,
+ (png_bytep) "miNE", 1);
+ # if PNG_LIBPNG_VER < 10600
+ /* Deal with unknown chunk location bug in 1.5.x and earlier */
+ png_set_unknown_chunk_location(png, info, 0, PNG_HAVE_IHDR);
+ png_set_unknown_chunk_location(png, info, 1, PNG_AFTER_IDAT);
+ # endif
+ # if PNG_LIBPNG_VER < 10500
+ /* PNG_AFTER_IDAT writes two copies of the chunk prior to libpng-1.5.0,
+ * one before IDAT and another after IDAT, so don't use it; only use
+ * PNG_HAVE_IHDR location. This call resets the location previously
+ * set by assignment and png_set_unknown_chunk_location() for chunk 1.
+ */
+ png_set_unknown_chunk_location(png, info, 1, PNG_HAVE_IHDR);
+ # endif
+ #endif
.SS The high-level write interface
@@ -3059,17 +4007,19 @@ file so that decoders can recover the original data if desired.
/* Set the true bit depth of the image data */
if (color_type & PNG_COLOR_MASK_COLOR)
{
- sig_bit.red = true_bit_depth;
- sig_bit.green = true_bit_depth;
- sig_bit.blue = true_bit_depth;
+ sig_bit.red = true_bit_depth;
+ sig_bit.green = true_bit_depth;
+ sig_bit.blue = true_bit_depth;
}
+
else
{
- sig_bit.gray = true_bit_depth;
+ sig_bit.gray = true_bit_depth;
}
+
if (color_type & PNG_COLOR_MASK_ALPHA)
{
- sig_bit.alpha = true_bit_depth;
+ sig_bit.alpha = true_bit_depth;
}
png_set_sBIT(png_ptr, info_ptr, &sig_bit);
@@ -3081,7 +4031,7 @@ is required by PNG.
png_set_shift(png_ptr, &sig_bit);
-PNG files store 16 bit pixels in network byte order (big-endian,
+PNG files store 16-bit pixels in network byte order (big-endian,
ie. most significant bits first). This code would be used if they are
supplied the other way (little-endian, i.e. least significant bits
first, the way PCs store them):
@@ -3115,11 +4065,24 @@ with
You must supply the function
- void write_transform_fn(png_ptr ptr, row_info_ptr
+ void write_transform_fn(png_structp png_ptr, png_row_infop
row_info, png_bytep data)
See pngtest.c for a working example. Your function will be called
-before any of the other transformations are processed.
+before any of the other transformations are processed. If supported
+libpng also supplies an information routine that may be called from
+your callback:
+
+ png_get_current_row_number(png_ptr);
+ png_get_current_pass_number(png_ptr);
+
+This returns the current row passed to the transform. With interlaced
+images the value returned is the row in the input sub-image image. Use
+PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
+find the output pixel (x,y) given an interlaced sub-image pixel (row,col,pass).
+
+The discussion of interlace handling above contains more information on how to
+use these values.
You can also set up a pointer to a user structure for use by your
callback function.
@@ -3201,25 +4164,39 @@ for details of which pixels to write when.
If you don't want libpng to handle the interlacing details, just
use png_set_interlace_handling() and call png_write_rows() the
-correct number of times to write all seven sub-images.
+correct number of times to write all the sub-images
+(png_set_interlace_handling() returns the number of sub-images.)
If you want libpng to build the sub-images, call this before you start
writing any rows:
- number_of_passes =
- png_set_interlace_handling(png_ptr);
+ number_of_passes = png_set_interlace_handling(png_ptr);
This will return the number of passes needed. Currently, this is seven,
but may change if another interlace type is added.
Then write the complete image number_of_passes times.
- png_write_rows(png_ptr, row_pointers,
- number_of_rows);
+ png_write_rows(png_ptr, row_pointers, number_of_rows);
+
+Think carefully before you write an interlaced image. Typically code that
+reads such images reads all the image data into memory, uncompressed, before
+doing any processing. Only code that can display an image on the fly can
+take advantage of the interlacing and even then the image has to be exactly
+the correct size for the output device, because scaling an image requires
+adjacent pixels and these are not available until all the passes have been
+read.
-As some of these rows are not used, and thus return immediately, you may
-want to read about interlacing in the PNG specification, and only update
-the rows that are actually used.
+If you do write an interlaced image you will hardly ever need to handle
+the interlacing yourself. Call png_set_interlace_handling() and use the
+approach described above.
+
+The only time it is conceivable that you will really need to write an
+interlaced image pass-by-pass is when you have read one pass by pass and
+made some pixel-by-pixel transformation to it, as described in the read
+code above. In this case use the PNG_PASS_ROWS and PNG_PASS_COLS macros
+to determine the size of each sub-image in turn and simply write the rows
+you obtained from the read code.
.SS Finishing a sequential write
@@ -3238,6 +4215,7 @@ It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, seq)
+
mask - identifies data to be freed, a mask
containing the bitwise OR of one or
more of
@@ -3247,14 +4225,15 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
+
seq - sequence number of item to be freed
- (-1 for all items)
+ (\-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those cases do nothing.
The "seq" parameter is ignored if only one item of the selected data
-type, such as PLTE, is allowed. If "seq" is not -1, and multiple items
+type, such as PLTE, is allowed. If "seq" is not \-1, and multiple items
are allowed for the data type identified in the mask, such as text or
sPLT, only the n'th item in the structure is freed, where n is "seq".
@@ -3265,22 +4244,25 @@ png_destroy_write_struct().
The default behavior is only to free data that was allocated internally
by libpng. This can be changed, so that libpng will not free the data,
or so that it will free data that was allocated by the user with png_malloc()
-or png_zalloc() and passed in via a png_set_*() function, with
+or png_calloc() and passed in via a png_set_*() function, with
png_data_freer(png_ptr, info_ptr, freer, mask)
- mask - which data elements are affected
- same choices as in png_free_data()
+
freer - one of
PNG_DESTROY_WILL_FREE_DATA
PNG_SET_WILL_FREE_DATA
PNG_USER_WILL_FREE_DATA
+ mask - which data elements are affected
+ same choices as in png_free_data()
+
For example, to transfer responsibility for some data from a read structure
to a write structure, you could use
png_data_freer(read_ptr, read_info_ptr,
PNG_USER_WILL_FREE_DATA,
PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
+
png_data_freer(write_ptr, write_info_ptr,
PNG_DESTROY_WILL_FREE_DATA,
PNG_FREE_PLTE|PNG_FREE_tRNS|PNG_FREE_hIST)
@@ -3298,7 +4280,7 @@ When the user assumes responsibility for libpng-allocated data, the
application must use
png_free() to free it, and when the user transfers responsibility to libpng
for data that the user has allocated, the user must have used png_malloc()
-or png_zalloc() to allocate it.
+or png_calloc() to allocate it.
If you allocated text_ptr.text, text_ptr.lang, and text_ptr.translated_keyword
separately, do not transfer responsibility for freeing text_ptr to libpng,
@@ -3308,7 +4290,424 @@ if you transfer responsibility for free'ing text_ptr from libpng to your
application, your application must not separately free those members.
For a more compact example of writing a PNG image, see the file example.c.
-.SH V. Modifying/Customizing libpng:
+.SH V. Simplified API
+
+The simplified API, which became available in libpng-1.6.0, hides the details
+of both libpng and the PNG file format itself.
+It allows PNG files to be read into a very limited number of
+in-memory bitmap formats or to be written from the same formats. If these
+formats do not accommodate your needs then you can, and should, use the more
+sophisticated APIs above - these support a wide variety of in-memory formats
+and a wide variety of sophisticated transformations to those formats as well
+as a wide variety of APIs to manipulate ancillary information.
+
+To read a PNG file using the simplified API:
+
+ 1) Declare a 'png_image' structure (see below) on the stack, set the
+ version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
+ (this is REQUIRED, your program may crash if you don't do it.)
+
+ 2) Call the appropriate png_image_begin_read... function.
+
+ 3) Set the png_image 'format' member to the required sample format.
+
+ 4) Allocate a buffer for the image and, if required, the color-map.
+
+ 5) Call png_image_finish_read to read the image and, if required, the
+ color-map into your buffers.
+
+There are no restrictions on the format of the PNG input itself; all valid
+color types, bit depths, and interlace methods are acceptable, and the
+input image is transformed as necessary to the requested in-memory format
+during the png_image_finish_read() step. The only caveat is that if you
+request a color-mapped image from a PNG that is full-color or makes
+complex use of an alpha channel the transformation is extremely lossy and the
+result may look terrible.
+
+To write a PNG file using the simplified API:
+
+ 1) Declare a 'png_image' structure on the stack and memset()
+ it to all zero.
+
+ 2) Initialize the members of the structure that describe the
+ image, setting the 'format' member to the format of the
+ image samples.
+
+ 3) Call the appropriate png_image_write... function with a
+ pointer to the image and, if necessary, the color-map to write
+ the PNG data.
+
+png_image is a structure that describes the in-memory format of an image
+when it is being read or defines the in-memory format of an image that you
+need to write. The "png_image" structure contains the following members:
+
+ png_controlp opaque Initialize to NULL, free with png_image_free
+ png_uint_32 version Set to PNG_IMAGE_VERSION
+ png_uint_32 width Image width in pixels (columns)
+ png_uint_32 height Image height in pixels (rows)
+ png_uint_32 format Image format as defined below
+ png_uint_32 flags A bit mask containing informational flags
+ png_uint_32 colormap_entries; Number of entries in the color-map
+ png_uint_32 warning_or_error;
+ char message[64];
+
+In the event of an error or warning the "warning_or_error"
+field will be set to a non-zero value and the 'message' field will contain
+a '\0' terminated string with the libpng error or warning message. If both
+warnings and an error were encountered, only the error is recorded. If there
+are multiple warnings, only the first one is recorded.
+
+The upper 30 bits of the "warning_or_error" value are reserved; the low two
+bits contain a two bit code such that a value more than 1 indicates a failure
+in the API just called:
+
+ 0 - no warning or error
+ 1 - warning
+ 2 - error
+ 3 - error preceded by warning
+
+The pixels (samples) of the image have one to four channels whose components
+have original values in the range 0 to 1.0:
+
+ 1: A single gray or luminance channel (G).
+ 2: A gray/luminance channel and an alpha channel (GA).
+ 3: Three red, green, blue color channels (RGB).
+ 4: Three color channels and an alpha channel (RGBA).
+
+The channels are encoded in one of two ways:
+
+ a) As a small integer, value 0..255, contained in a single byte. For the
+alpha channel the original value is simply value/255. For the color or
+luminance channels the value is encoded according to the sRGB specification
+and matches the 8-bit format expected by typical display devices.
+
+The color/gray channels are not scaled (pre-multiplied) by the alpha
+channel and are suitable for passing to color management software.
+
+ b) As a value in the range 0..65535, contained in a 2-byte integer, in
+the native byte order of the platform on which the application is running.
+All channels can be converted to the original value by dividing by 65535; all
+channels are linear. Color channels use the RGB encoding (RGB end-points) of
+the sRGB specification. This encoding is identified by the
+PNG_FORMAT_FLAG_LINEAR flag below.
+
+When the simplified API needs to convert between sRGB and linear colorspaces,
+the actual sRGB transfer curve defined in the sRGB specification (see the
+article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+approximation used elsewhere in libpng.
+
+When an alpha channel is present it is expected to denote pixel coverage
+of the color or luminance channels and is returned as an associated alpha
+channel: the color/gray channels are scaled (pre-multiplied) by the alpha
+value.
+
+The samples are either contained directly in the image data, between 1 and 8
+bytes per pixel according to the encoding, or are held in a color-map indexed
+by bytes in the image data. In the case of a color-map the color-map entries
+are individual samples, encoded as above, and the image data has one byte per
+pixel to select the relevant sample from the color-map.
+
+PNG_FORMAT_*
+
+The #defines to be used in png_image::format. Each #define identifies a
+particular layout of channel data and, if present, alpha values. There are
+separate defines for each of the two component encodings.
+
+A format is built up using single bit flag values. All combinations are
+valid. Formats can be built up from the flag values or you can use one of
+the predefined values below. When testing formats always use the FORMAT_FLAG
+macros to test for individual features - future versions of the library may
+add new flags.
+
+When reading or writing color-mapped images the format should be set to the
+format of the entries in the color-map then png_image_{read,write}_colormap
+called to read or write the color-map and set the format correctly for the
+image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
+
+NOTE: libpng can be built with particular features disabled. If you see
+compiler errors because the definition of one of the following flags has been
+compiled out it is because libpng does not have the required support. It is
+possible, however, for the libpng configuration to enable the format on just
+read or just write; in that case you may see an error at run time.
+You can guard against this by checking for the definition of the
+appropriate "_SUPPORTED" macro, one of:
+
+ PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
+
+ PNG_FORMAT_FLAG_ALPHA format with an alpha channel
+ PNG_FORMAT_FLAG_COLOR color format: otherwise grayscale
+ PNG_FORMAT_FLAG_LINEAR 2-byte channels else 1-byte
+ PNG_FORMAT_FLAG_COLORMAP image data is color-mapped
+ PNG_FORMAT_FLAG_BGR BGR colors, else order is RGB
+ PNG_FORMAT_FLAG_AFIRST alpha channel comes first
+
+Supported formats are as follows. Future versions of libpng may support more
+formats; for compatibility with older versions simply check if the format
+macro is defined using #ifdef. These defines describe the in-memory layout
+of the components of the pixels of the image.
+
+First the single byte (sRGB) formats:
+
+ PNG_FORMAT_GRAY
+ PNG_FORMAT_GA
+ PNG_FORMAT_AG
+ PNG_FORMAT_RGB
+ PNG_FORMAT_BGR
+ PNG_FORMAT_RGBA
+ PNG_FORMAT_ARGB
+ PNG_FORMAT_BGRA
+ PNG_FORMAT_ABGR
+
+Then the linear 2-byte formats. When naming these "Y" is used to
+indicate a luminance (gray) channel. The component order within the pixel
+is always the same - there is no provision for swapping the order of the
+components in the linear format. The components are 16-bit integers in
+the native byte order for your platform, and there is no provision for
+swapping the bytes to a different endian condition.
+
+ PNG_FORMAT_LINEAR_Y
+ PNG_FORMAT_LINEAR_Y_ALPHA
+ PNG_FORMAT_LINEAR_RGB
+ PNG_FORMAT_LINEAR_RGB_ALPHA
+
+With color-mapped formats the image data is one byte for each pixel. The byte
+is an index into the color-map which is formatted as above. To obtain a
+color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
+to one of the above definitions, or you can use one of the definitions below.
+
+ PNG_FORMAT_RGB_COLORMAP
+ PNG_FORMAT_BGR_COLORMAP
+ PNG_FORMAT_RGBA_COLORMAP
+ PNG_FORMAT_ARGB_COLORMAP
+ PNG_FORMAT_BGRA_COLORMAP
+ PNG_FORMAT_ABGR_COLORMAP
+
+PNG_IMAGE macros
+
+These are convenience macros to derive information from a png_image
+structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
+actual image sample values - either the entries in the color-map or the
+pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
+for the pixels and will always return 1 for color-mapped formats. The
+remaining macros return information about the rows in the image and the
+complete image.
+
+NOTE: All the macros that take a png_image::format parameter are compile time
+constants if the format parameter is, itself, a constant. Therefore these
+macros can be used in array declarations and case labels where required.
+Similarly the macros are also pre-processor constants (sizeof is not used) so
+they can be used in #if tests.
+
+ PNG_IMAGE_SAMPLE_CHANNELS(fmt)
+ Returns the total number of channels in a given format: 1..4
+
+ PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)
+ Returns the size in bytes of a single component of a pixel or color-map
+ entry (as appropriate) in the image: 1 or 2.
+
+ PNG_IMAGE_SAMPLE_SIZE(fmt)
+ This is the size of the sample data for one sample. If the image is
+ color-mapped it is the size of one color-map entry (and image pixels are
+ one byte in size), otherwise it is the size of one image pixel.
+
+ PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)
+ The maximum size of the color-map required by the format expressed in a
+ count of components. This can be used to compile-time allocate a
+ color-map:
+
+ png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
+
+ png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
+
+ Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+ information from one of the png_image_begin_read_ APIs and dynamically
+ allocate the required memory.
+
+ PNG_IMAGE_COLORMAP_SIZE(fmt)
+ The size of the color-map required by the format; this is the size of the
+ color-map buffer passed to the png_image_{read,write}_colormap APIs. It is
+ a fixed number determined by the format so can easily be allocated on the
+ stack if necessary.
+
+Corresponding information about the pixels
+
+ PNG_IMAGE_PIXEL_CHANNELS(fmt)
+ The number of separate channels (components) in a pixel; 1 for a
+ color-mapped image.
+
+ PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
+ The size, in bytes, of each component in a pixel; 1 for a color-mapped
+ image.
+
+ PNG_IMAGE_PIXEL_SIZE(fmt)
+ The size, in bytes, of a complete pixel; 1 for a color-mapped image.
+
+Information about the whole row, or whole image
+
+ PNG_IMAGE_ROW_STRIDE(image)
+ Returns the total number of components in a single row of the image; this
+ is the minimum 'row stride', the minimum count of components between each
+ row. For a color-mapped image this is the minimum number of bytes in a
+ row.
+
+ If you need the stride measured in bytes, row_stride_bytes is
+ PNG_IMAGE_ROW_STRIDE(image) * PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)
+ plus any padding bytes that your application might need, for example
+ to start the next row on a 4-byte boundary.
+
+ PNG_IMAGE_BUFFER_SIZE(image, row_stride)
+ Return the size, in bytes, of an image buffer given a png_image and a row
+ stride - the number of components to leave space for in each row.
+
+ PNG_IMAGE_SIZE(image)
+ Return the size, in bytes, of the image in memory given just a png_image;
+ the row stride is the minimum stride required for the image.
+
+ PNG_IMAGE_COLORMAP_SIZE(image)
+ Return the size, in bytes, of the color-map of this image. If the image
+ format is not a color-map format this will return a size sufficient for
+ 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
+ you don't want to allocate a color-map in this case.
+
+PNG_IMAGE_FLAG_*
+
+Flags containing additional information about the image are held in
+the 'flags' field of png_image.
+
+ PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01
+ This indicates that the RGB values of the in-memory bitmap do not
+ correspond to the red, green and blue end-points defined by sRGB.
+
+ PNG_IMAGE_FLAG_FAST == 0x02
+ On write emphasise speed over compression; the resultant PNG file will be
+ larger but will be produced significantly faster, particular for large
+ images. Do not use this option for images which will be distributed, only
+ used it when producing intermediate files that will be read back in
+ repeatedly. For a typical 24-bit image the option will double the read
+ speed at the cost of increasing the image size by 25%, however for many
+ more compressible images the PNG file can be 10 times larger with only a
+ slight speed gain.
+
+ PNG_IMAGE_FLAG_16BIT_sRGB == 0x04
+ On read if the image is a 16-bit per component image and there is no gAMA
+ or sRGB chunk assume that the components are sRGB encoded. Notice that
+ images output by the simplified API always have gamma information; setting
+ this flag only affects the interpretation of 16-bit images from an
+ external source. It is recommended that the application expose this flag
+ to the user; the user can normally easily recognize the difference between
+ linear and sRGB encoding. This flag has no effect on write - the data
+ passed to the write APIs must have the correct encoding (as defined
+ above.)
+
+ If the flag is not set (the default) input 16-bit per component data is
+ assumed to be linear.
+
+ NOTE: the flag can only be set after the png_image_begin_read_ call,
+ because that call initializes the 'flags' field.
+
+READ APIs
+
+ The png_image passed to the read APIs must have been initialized by setting
+ the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.)
+
+ int png_image_begin_read_from_file( png_imagep image,
+ const char *file_name)
+
+ The named file is opened for read and the image header
+ is filled in from the PNG header in the file.
+
+ int png_image_begin_read_from_stdio (png_imagep image,
+ FILE* file)
+
+ The PNG header is read from the stdio FILE object.
+
+ int png_image_begin_read_from_memory(png_imagep image,
+ png_const_voidp memory, size_t size)
+
+ The PNG header is read from the given memory buffer.
+
+ int png_image_finish_read(png_imagep image,
+ png_colorp background, void *buffer,
+ png_int_32 row_stride, void *colormap));
+
+ Finish reading the image into the supplied buffer and
+ clean up the png_image structure.
+
+ row_stride is the step, in png_byte or png_uint_16 units
+ as appropriate, between adjacent rows. A positive stride
+ indicates that the top-most row is first in the buffer -
+ the normal top-down arrangement. A negative stride
+ indicates that the bottom-most row is first in the buffer.
+
+ background need only be supplied if an alpha channel must
+ be removed from a png_byte format and the removal is to be
+ done by compositing on a solid color; otherwise it may be
+ NULL and any composition will be done directly onto the
+ buffer. The value is an sRGB color to use for the
+ background, for grayscale output the green channel is used.
+
+ For linear output removing the alpha channel is always done
+ by compositing on black.
+
+ void png_image_free(png_imagep image)
+
+ Free any data allocated by libpng in image->opaque,
+ setting the pointer to NULL. May be called at any time
+ after the structure is initialized.
+
+When the simplified API needs to convert between sRGB and linear colorspaces,
+the actual sRGB transfer curve defined in the sRGB specification (see the
+article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
+approximation used elsewhere in libpng.
+
+WRITE APIS
+
+For write you must initialize a png_image structure to describe the image to
+be written:
+
+ version: must be set to PNG_IMAGE_VERSION
+ opaque: must be initialized to NULL
+ width: image width in pixels
+ height: image height in rows
+ format: the format of the data you wish to write
+ flags: set to 0 unless one of the defined flags applies; set
+ PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images
+ where the RGB values do not correspond to the colors in sRGB.
+ colormap_entries: set to the number of entries in the color-map (0 to 256)
+
+ int png_image_write_to_file, (png_imagep image,
+ const char *file, int convert_to_8bit, const void *buffer,
+ png_int_32 row_stride, const void *colormap));
+
+ Write the image to the named file.
+
+ int png_image_write_to_memory (png_imagep image, void *memory,
+ png_alloc_size_t * PNG_RESTRICT memory_bytes,
+ int convert_to_8_bit, const void *buffer, ptrdiff_t row_stride,
+ const void *colormap));
+
+ Write the image to memory.
+
+ int png_image_write_to_stdio(png_imagep image, FILE *file,
+ int convert_to_8_bit, const void *buffer,
+ png_int_32 row_stride, const void *colormap)
+
+ Write the image to the given (FILE*).
+
+With all write APIs if image is in one of the linear formats with
+(png_uint_16) data then setting convert_to_8_bit will cause the output to be
+a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise
+a 16-bit linear encoded PNG file is written.
+
+With all APIs row_stride is handled as in the read APIs - it is the spacing
+from one row to the next in component sized units (float) and if negative
+indicates a bottom-up row layout in the buffer. If you pass zero, libpng will
+calculate the row_stride for you from the width and number of channels.
+
+Note that the write API does not support interlacing, sub-8-bit pixels,
+indexed (paletted) images, or most ancillary chunks.
+
+.SH VI. Modifying/Customizing libpng
There are two issues here. The first is changing how libpng does
standard things like memory allocation, input/output, and error handling.
@@ -3326,24 +4725,25 @@ in pngmem.c, pngrio.c, pngwio.c, and pngerror.c, respectively. To change
these functions, call the appropriate png_set_*_fn() function.
Memory allocation is done through the functions png_malloc(), png_calloc(),
-and png_free(). These currently just call the standard C functions.
-png_calloc() calls png_malloc() and then png_memset() to clear the newly
-allocated memory to zero. If your pointers can't access more then 64K
-at a time, you will want to set MAXSEG_64K in zlib.h. Since it is
-unlikely that the method of handling memory allocation on a platform
-will change between applications, these functions must be modified in
-the library at compile time. If you prefer to use a different method
-of allocating and freeing data, you can use png_create_read_struct_2() or
-png_create_write_struct_2() to register your own functions as described
-above. These functions also provide a void pointer that can be retrieved
-via
+and png_free(). The png_malloc() and png_free() functions currently just
+call the standard C functions and png_calloc() calls png_malloc() and then
+clears the newly allocated memory to zero; note that png_calloc(png_ptr, size)
+is not the same as the calloc(number, size) function provided by stdlib.h.
+There is limited support for certain systems with segmented memory
+architectures and the types of pointers declared by png.h match this; you
+will have to use appropriate pointers in your application. If you prefer
+to use a different method of allocating and freeing data, you can use
+png_create_read_struct_2() or png_create_write_struct_2() to register your
+own functions as described above. These functions also provide a void
+pointer that can be retrieved via
mem_ptr=png_get_mem_ptr(png_ptr);
Your replacement memory functions must have prototypes as follows:
png_voidp malloc_fn(png_structp png_ptr,
- png_size_t size);
+ png_alloc_size_t size);
+
void free_fn(png_structp png_ptr, png_voidp ptr);
Your malloc_fn() must return NULL in case of failure. The png_malloc()
@@ -3375,9 +4775,11 @@ png_get_io_ptr(). For example:
The replacement I/O functions must have prototypes as follows:
void user_read_data(png_structp png_ptr,
- png_bytep data, png_size_t length);
+ png_bytep data, size_t length);
+
void user_write_data(png_structp png_ptr,
- png_bytep data, png_size_t length);
+ png_bytep data, size_t length);
+
void user_flush_data(png_structp png_ptr);
The user_read_data() function is responsible for detecting and
@@ -3394,8 +4796,9 @@ Error handling in libpng is done through png_error() and png_warning().
Errors handled through png_error() are fatal, meaning that png_error()
should never return to its caller. Currently, this is handled via
setjmp() and longjmp() (unless you have compiled libpng with
-PNG_SETJMP_NOT_SUPPORTED, in which case it is handled via PNG_ABORT()),
-but you could change this to do things like exit() if you should wish.
+PNG_NO_SETJMP, in which case it is handled via PNG_ABORT()),
+but you could change this to do things like exit() if you should wish,
+as long as your function does not return.
On non-fatal errors, png_warning() is called
to print a warning message, and then control returns to the calling code.
@@ -3412,8 +4815,6 @@ functions after png_create_*_struct() has been called by calling:
png_voidp error_ptr, png_error_ptr error_fn,
png_error_ptr warning_fn);
- png_voidp error_ptr = png_get_error_ptr(png_ptr);
-
If NULL is supplied for either error_fn or warning_fn, then the libpng
default function will be used, calling fprintf() and/or longjmp() if a
problem is encountered. The replacement error functions should have
@@ -3421,9 +4822,15 @@ parameters as follows:
void user_error_fn(png_structp png_ptr,
png_const_charp error_msg);
+
void user_warning_fn(png_structp png_ptr,
png_const_charp warning_msg);
+Then, within your user_error_fn or user_warning_fn, you can retrieve
+the error_ptr if you need it, by calling
+
+ png_voidp error_ptr = png_get_error_ptr(png_ptr);
+
The motivation behind using setjmp() and longjmp() is the C++ throw and
catch exception handling methods. This makes the code much easier to write,
as there is no need to check every return code of every function call.
@@ -3431,7 +4838,20 @@ However, there are some uncertainties about the status of local variables
after a longjmp, so the user may want to be careful about doing anything
after setjmp returns non-zero besides returning itself. Consult your
compiler documentation for more details. For an alternative approach, you
-may wish to use the "cexcept" facility (see http://cexcept.sourceforge.net).
+may wish to use the "cexcept" facility (see https://cexcept.sourceforge.io/),
+which is illustrated in pngvalid.c and in contrib/visupng.
+
+Beginning in libpng-1.4.0, the png_set_benign_errors() API became available.
+You can use this to handle certain errors (normally handled as errors)
+as warnings.
+
+ png_set_benign_errors (png_ptr, int allowed);
+
+ allowed: 0: treat png_benign_error() as an error.
+ 1: treat png_benign_error() as a warning.
+
+As of libpng-1.6.0, the default condition is to treat benign errors as
+warnings while reading and as errors while writing.
.SS Custom chunks
@@ -3449,8 +4869,11 @@ and look at how other chunks were designed, so you can do things
similarly. Second, check out the sections of libpng that read and
write chunks. Try to find a chunk that is similar to yours and use
it as a template. More details can be found in the comments inside
-the code. It is best to handle unknown chunks in a generic method,
-via callback functions, instead of by modifying libpng functions.
+the code. It is best to handle private or unknown chunks in a generic method,
+via callback functions, instead of by modifying libpng functions. This
+is illustrated in pngtest.c, which uses a callback function to handle a
+private "vpAg" chunk and the new "sTER" chunk, which are both unknown to
+libpng.
If you wish to write your own transformation for the data, look through
the part of the code that does the transformations, and check out some of
@@ -3458,29 +4881,6 @@ the simpler ones to get an idea of how they work. Try to find a similar
transformation to the one you want to add and copy off of it. More details
can be found in the comments inside the code itself.
-.SS Configuring for 16 bit platforms
-
-You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more then 64K at a time. Even if you can, the memory
-won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K.
-
-.SS Configuring for DOS
-
-For DOS users who only have access to the lower 640K, you will
-have to limit zlib's memory usage via a png_set_compression_mem_level()
-call. See zlib.h or zconf.h in the zlib library for more information.
-
-.SS Configuring for Medium Model
-
-Libpng's support for medium model has been tested on most of the popular
-compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
-defined, and FAR gets defined to far in pngconf.h, and you should be
-all set. Everything in the library (except for zlib's structure) is
-expecting far data. You must use the typedefs with the p or pp on
-the end for pointers (or at least look at them and be careful). Make
-note that the rows of data are defined as png_bytepp, which is an
-unsigned char far * far *.
-
.SS Configuring for gui/windowing platforms:
You will need to write new error and warning functions that use the GUI
@@ -3490,15 +4890,6 @@ in order to have them available during the structure initialization.
They can be changed later via png_set_error_fn(). On some compilers,
you may also have to change the memory allocators (png_malloc, etc.).
-.SS Configuring for compiler xxx:
-
-All includes for libpng are in pngconf.h. If you need to add, change
-or delete an include, this is the place to do it.
-The includes that are not needed outside libpng are protected by the
-PNG_INTERNAL definition, which is only defined for those routines inside
-libpng itself. The files in libpng proper only include png.h, which
-includes pngconf.h.
-
.SS Configuring zlib:
There are special functions to configure the compression. Perhaps the
@@ -3513,6 +4904,7 @@ specify no compression (Z_NO_COMPRESSION = 0), but this would create
files larger than just storing the raw bitmap. You can specify the
compression level by calling:
+ #include zlib.h
png_set_compression_level(png_ptr, level);
Another useful one is to reduce the memory level used by the library.
@@ -3523,19 +4915,45 @@ other things, lower levels will result in sections of incompressible
data being emitted in smaller stored blocks, with a correspondingly
larger relative overhead of up to 15% in the worst case.
+ #include zlib.h
png_set_compression_mem_level(png_ptr, level);
The other functions are for configuring zlib. They are not recommended
for normal use and may result in writing an invalid PNG file. See
zlib.h for more information on what these mean.
+ #include zlib.h
png_set_compression_strategy(png_ptr,
strategy);
+
png_set_compression_window_bits(png_ptr,
window_bits);
+
png_set_compression_method(png_ptr, method);
+
+This controls the size of the IDAT chunks (default 8192):
+
png_set_compression_buffer_size(png_ptr, size);
+As of libpng version 1.5.4, additional APIs became
+available to set these separately for non-IDAT
+compressed chunks such as zTXt, iTXt, and iCCP:
+
+ #include zlib.h
+ #if PNG_LIBPNG_VER >= 10504
+ png_set_text_compression_level(png_ptr, level);
+
+ png_set_text_compression_mem_level(png_ptr, level);
+
+ png_set_text_compression_strategy(png_ptr,
+ strategy);
+
+ png_set_text_compression_window_bits(png_ptr,
+ window_bits);
+
+ png_set_text_compression_method(png_ptr, method);
+ #endif
+
.SS Controlling row filtering
If you want to control whether libpng uses filtering or not, which
@@ -3550,8 +4968,9 @@ for any images with bit depths less than 8 bits/pixel.
The 'method' parameter sets the main filtering method, which is
currently only '0' in the PNG 1.2 specification. The 'filters'
parameter sets which filter(s), if any, should be used for each
-scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
-to turn filtering on and off, respectively.
+scanline. Possible values are PNG_ALL_FILTERS, PNG_NO_FILTERS,
+or PNG_FAST_FILTERS to turn filtering on and off, or to turn on
+just the fast-decoding subset of filters, respectively.
Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB,
PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise
@@ -3565,12 +4984,19 @@ means the first row must always be adaptively filtered, because libpng
currently does not allocate the filter buffers until png_write_row()
is called for the first time.)
- filters = PNG_FILTER_NONE | PNG_FILTER_SUB
+ filters = PNG_NO_FILTERS;
+ filters = PNG_ALL_FILTERS;
+ filters = PNG_FAST_FILTERS;
+
+ or
+
+ filters = PNG_FILTER_NONE | PNG_FILTER_SUB |
PNG_FILTER_UP | PNG_FILTER_AVG |
- PNG_FILTER_PAETH | PNG_ALL_FILTERS;
+ PNG_FILTER_PAETH;
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
filters);
+
The second parameter can also be
PNG_INTRAPIXEL_DIFFERENCING if you are
writing a PNG to be embedded in a MNG
@@ -3578,79 +5004,6 @@ is called for the first time.)
same as the value of filter_method used
in png_set_IHDR().
-It is also possible to influence how libpng chooses from among the
-available filters. This is done in one or both of two ways - by
-telling it how important it is to keep the same filter for successive
-rows, and by telling it the relative computational costs of the filters.
-
- double weights[3] = {1.5, 1.3, 1.1},
- costs[PNG_FILTER_VALUE_LAST] =
- {1.0, 1.3, 1.3, 1.5, 1.7};
-
- png_set_filter_heuristics(png_ptr,
- PNG_FILTER_HEURISTIC_WEIGHTED, 3,
- weights, costs);
-
-The weights are multiplying factors that indicate to libpng that the
-row filter should be the same for successive rows unless another row filter
-is that many times better than the previous filter. In the above example,
-if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
-"sum of absolute differences" 1.5 x 1.3 times higher than other filters
-and still be chosen, while the NONE filter could have a sum 1.1 times
-higher than other filters and still be chosen. Unspecified weights are
-taken to be 1.0, and the specified weights should probably be declining
-like those above in order to emphasize recent filters over older filters.
-
-The filter costs specify for each filter type a relative decoding cost
-to be considered when selecting row filters. This means that filters
-with higher costs are less likely to be chosen over filters with lower
-costs, unless their "sum of absolute differences" is that much smaller.
-The costs do not necessarily reflect the exact computational speeds of
-the various filters, since this would unduly influence the final image
-size.
-
-Note that the numbers above were invented purely for this example and
-are given only to help explain the function usage. Little testing has
-been done to find optimum values for either the costs or the weights.
-
-.SS Removing unwanted object code
-
-There are a bunch of #define's in pngconf.h that control what parts of
-libpng are compiled. All the defines end in _SUPPORTED. If you are
-never going to use a capability, you can change the #define to #undef
-before recompiling libpng and save yourself code and data space, or
-you can turn off individual capabilities with defines that begin with
-PNG_NO_.
-
-You can also turn all of the transforms and ancillary chunk capabilities
-off en masse with compiler directives that define
-PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
-or all four,
-along with directives to turn on any of the capabilities that you do
-want. The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
-transformations but still leave the library fully capable of reading
-and writing PNG files with all known public chunks. Use of the
-PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
-that is incapable of reading or writing ancillary chunks. If you are
-not using the progressive reading capability, you can turn that off
-with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
-capability, which you'll still have).
-
-All the reading and writing specific code are in separate files, so the
-linker should only grab the files it needs. However, if you want to
-make sure, or if you are building a stand alone library, all the
-reading files start with pngr and all the writing files start with
-pngw. The files that don't match either (like png.c, pngtrans.c, etc.)
-are used for both reading and writing, and always need to be included.
-The progressive reader is in pngpread.c
-
-If you are creating or distributing a dynamically linked library (a .so
-or DLL file), you should not remove or disable any parts of the library,
-as this will cause applications linked with different versions of the
-library to fail if they call functions not available in your library.
-The size of the library itself should not be an issue, because only
-those sections that are actually used will be loaded into memory.
-
.SS Requesting debug printout
The macro definition PNG_DEBUG can be used to request debugging
@@ -3670,12 +5023,12 @@ the message, "message" is the formatted string to be printed,
and p1 and p2 are parameters that are to be embedded in the string
according to printf-style formatting directives. For example,
- png_debug1(2, "foo=%d\n", foo);
+ png_debug1(2, "foo=%d", foo);
is expanded to
- if(PNG_DEBUG > 2)
- fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+ if (PNG_DEBUG > 2)
+ fprintf(PNG_DEBUG_FILE, "foo=%d\en", foo);
When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
can still use PNG_DEBUG to control your own debugging:
@@ -3688,7 +5041,7 @@ When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
having level = 0 will be printed. There aren't any such statements in
this version of libpng, but if you insert some they will be printed.
-.SH VI. MNG support
+.SH VII. MNG support
The MNG specification (available at http://www.libpng.org/pub/mng) allows
certain extensions to PNG for PNG images that are embedded in MNG datastreams.
@@ -3696,11 +5049,13 @@ Libpng can support some of these extensions. To enable them, use the
png_permit_mng_features() function:
feature_set = png_permit_mng_features(png_ptr, mask)
+
mask is a png_uint_32 containing the bitwise OR of the
features you want to enable. These include
PNG_FLAG_MNG_EMPTY_PLTE
PNG_FLAG_MNG_FILTER_64
PNG_ALL_MNG_FEATURES
+
feature_set is a png_uint_32 that is the bitwise AND of
your mask with the set of MNG features that is
supported by the version of libpng that you are using.
@@ -3711,9 +5066,9 @@ in a MNG datastream. As a minimum, it must have the MNG 8-byte signature
and the MHDR and MEND chunks. Libpng does not provide support for these
or any other MNG chunks; your application must provide its own support for
them. You may wish to consider using libmng (available at
-http://www.libmng.com) instead.
+https://www.libmng.com/) instead.
-.SH VII. Changes to Libpng from version 0.88
+.SH VIII. Changes to Libpng from version 0.88
It should be noted that versions of libpng later than 0.96 are not
distributed by the original libpng author, Guy Schalnat, nor by
@@ -3725,7 +5080,7 @@ still alive and well, but they have moved on to other things.
The old libpng functions png_read_init(), png_write_init(),
png_info_init(), png_read_destroy(), and png_write_destroy() have been
moved to PNG_INTERNAL in version 0.95 to discourage their use. These
-functions will be removed from libpng version 2.0.0.
+functions will be removed from libpng version 1.4.0.
The preferred method of creating and initializing the libpng structures is
via the png_create_read_struct(), png_create_write_struct(), and
@@ -3748,6 +5103,9 @@ png_set_error_fn(), which is essentially the same function, but with a new
name to force compilation errors with applications that try to use the old
method.
+Support for the sCAL, iCCP, iTXt, and sPLT chunks was added at libpng-1.0.6;
+however, iTXt support was not enabled by default.
+
Starting with version 1.0.7, you can find out which version of the library
you are using at run-time:
@@ -3757,12 +5115,15 @@ The number libpng_vn is constructed from the major version, minor
version with leading zero, and release number with leading zero,
(e.g., libpng_vn for version 1.0.7 is 10007).
+Note that this function does not take a png_ptr, so you can call it
+before you've created one.
+
You can also check which version of png.h you used when compiling your
application:
png_uint_32 application_vn = PNG_LIBPNG_VER;
-.SH VIII. Changes to Libpng from version 1.0.x to 1.2.x
+.SH IX. Changes to Libpng from version 1.0.x to 1.2.x
Support for user memory management was enabled by default. To
accomplish this, the functions png_create_read_struct_2(),
@@ -3859,10 +5220,538 @@ which also expands tRNS to alpha was replaced with
png_set_expand_gray_1_2_4_to_8()
which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
-.SH IX. (Omitted)
+.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x
+
+Private libpng prototypes and macro definitions were moved from
+png.h and pngconf.h into a new pngpriv.h header file.
+
+Functions png_set_benign_errors(), png_benign_error(), and
+png_chunk_benign_error() were added.
+
+Support for setting the maximum amount of memory that the application
+will allocate for reading chunks was added, as a security measure.
+The functions png_set_chunk_cache_max() and png_get_chunk_cache_max()
+were added to the library.
+
+We implemented support for I/O states by adding png_ptr member io_state
+and functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
+
+We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
+input transforms.
+
+Checking for and reporting of errors in the IHDR chunk is more thorough.
+
+Support for global arrays was removed, to improve thread safety.
+
+Some obsolete/deprecated macros and functions have been removed.
+
+Typecasted NULL definitions such as
+ #define png_voidp_NULL (png_voidp)NULL
+were eliminated. If you used these in your application, just use
+NULL instead.
+
+The png_struct and info_struct members "trans" and "trans_values" were
+changed to "trans_alpha" and "trans_color", respectively.
+The obsolete, unused pnggccrd.c and pngvcrd.c files and related makefiles
+were removed.
-.SH X. Detecting libpng
+The PNG_1_0_X and PNG_1_2_X macros were eliminated.
+
+The PNG_LEGACY_SUPPORTED macro was eliminated.
+
+Many WIN32_WCE #ifdefs were removed.
+
+The functions png_read_init(info_ptr), png_write_init(info_ptr),
+png_info_init(info_ptr), png_read_destroy(), and png_write_destroy()
+have been removed. They have been deprecated since libpng-0.95.
+
+The png_permit_empty_plte() was removed. It has been deprecated
+since libpng-1.0.9. Use png_permit_mng_features() instead.
+
+We removed the obsolete stub functions png_get_mmx_flagmask(),
+png_set_mmx_thresholds(), png_get_asm_flags(),
+png_get_mmx_bitdepth_threshold(), png_get_mmx_rowbytes_threshold(),
+png_set_asm_flags(), and png_mmx_supported()
+
+We removed the obsolete png_check_sig(), png_memcpy_check(), and
+png_memset_check() functions. Instead use !png_sig_cmp(), memcpy(),
+and memset(), respectively.
+
+The function png_set_gray_1_2_4_to_8() was removed. It has been
+deprecated since libpng-1.0.18 and 1.2.9, when it was replaced with
+png_set_expand_gray_1_2_4_to_8() because the former function also
+expanded any tRNS chunk to an alpha channel.
+
+Macros for png_get_uint_16, png_get_uint_32, and png_get_int_32
+were added and are used by default instead of the corresponding
+functions. Unfortunately,
+from libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+
+We changed the prototype for png_malloc() from
+ png_malloc(png_structp png_ptr, png_uint_32 size)
+to
+ png_malloc(png_structp png_ptr, png_alloc_size_t size)
+
+This also applies to the prototype for the user replacement malloc_fn().
+
+The png_calloc() function was added and is used in place of
+of "png_malloc(); memset();" except in the case in png_read_png()
+where the array consists of pointers; in this case a "for" loop is used
+after the png_malloc() to set the pointers to NULL, to give robust.
+behavior in case the application runs out of memory part-way through
+the process.
+
+We changed the prototypes of png_get_compression_buffer_size() and
+png_set_compression_buffer_size() to work with size_t instead of
+png_uint_32.
+
+Support for numbered error messages was removed by default, since we
+never got around to actually numbering the error messages. The function
+png_set_strip_error_numbers() was removed from the library by default.
+
+The png_zalloc() and png_zfree() functions are no longer exported.
+The png_zalloc() function no longer zeroes out the memory that it
+allocates. Applications that called png_zalloc(png_ptr, number, size)
+can call png_calloc(png_ptr, number*size) instead, and can call
+png_free() instead of png_zfree().
+
+Support for dithering was disabled by default in libpng-1.4.0, because
+it has not been well tested and doesn't actually "dither".
+The code was not
+removed, however, and could be enabled by building libpng with
+PNG_READ_DITHER_SUPPORTED defined. In libpng-1.4.2, this support
+was re-enabled, but the function was renamed png_set_quantize() to
+reflect more accurately what it actually does. At the same time,
+the PNG_DITHER_[RED,GREEN_BLUE]_BITS macros were also renamed to
+PNG_QUANTIZE_[RED,GREEN,BLUE]_BITS, and PNG_READ_DITHER_SUPPORTED
+was renamed to PNG_READ_QUANTIZE_SUPPORTED.
+
+We removed the trailing '.' from the warning and error messages.
+
+.SH XI. Changes to Libpng from version 1.4.x to 1.5.x
+
+From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
+function) incorrectly returned a value of type png_uint_32.
+The incorrect macro was removed from libpng-1.4.5.
+
+Checking for invalid palette index on write was added at libpng
+1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues
+a benign error. This is enabled by default because this condition is an
+error according to the PNG specification, Clause 11.3.2, but the error can
+be ignored in each png_ptr with
+
+ png_set_check_for_invalid_index(png_ptr, allowed);
+
+ allowed - one of
+ 0: disable benign error (accept the
+ invalid data without warning).
+ 1: enable benign error (treat the
+ invalid data as an error or a
+ warning).
+
+If the error is ignored, or if png_benign_error() treats it as a warning,
+any invalid pixels are decoded as opaque black by the decoder and written
+as-is by the encoder.
+
+Retrieving the maximum palette index found was added at libpng-1.5.15.
+This statement must appear after png_read_png() or png_read_image() while
+reading, and after png_write_png() or png_write_image() while writing.
+
+ int max_palette = png_get_palette_max(png_ptr, info_ptr);
+
+This will return the maximum palette index found in the image, or "\-1" if
+the palette was not checked, or "0" if no palette was found. Note that this
+does not account for any palette index used by ancillary chunks such as the
+bKGD chunk; you must check those separately to determine the maximum
+palette index actually used.
+
+There are no substantial API changes between the non-deprecated parts of
+the 1.4.5 API and the 1.5.0 API; however, the ability to directly access
+members of the main libpng control structures, png_struct and png_info,
+deprecated in earlier versions of libpng, has been completely removed from
+libpng 1.5, and new private "pngstruct.h", "pnginfo.h", and "pngdebug.h"
+header files were created.
+
+We no longer include zlib.h in png.h. The include statement has been moved
+to pngstruct.h, where it is not accessible by applications. Applications that
+need access to information in zlib.h will need to add the '#include "zlib.h"'
+directive. It does not matter whether this is placed prior to or after
+the '"#include png.h"' directive.
+
+The png_sprintf(), png_strcpy(), and png_strncpy() macros are no longer used
+and were removed.
+
+We moved the png_strlen(), png_memcpy(), png_memset(), and png_memcmp()
+macros into a private header file (pngpriv.h) that is not accessible to
+applications.
+
+In png_get_iCCP, the type of "profile" was changed from png_charpp
+to png_bytepp, and in png_set_iCCP, from png_charp to png_const_bytep.
+
+There are changes of form in png.h, including new and changed macros to
+declare parts of the API. Some API functions with arguments that are
+pointers to data not modified within the function have been corrected to
+declare these arguments with const.
+
+Much of the internal use of C macros to control the library build has also
+changed and some of this is visible in the exported header files, in
+particular the use of macros to control data and API elements visible
+during application compilation may require significant revision to
+application code. (It is extremely rare for an application to do this.)
+
+Any program that compiled against libpng 1.4 and did not use deprecated
+features or access internal library structures should compile and work
+against libpng 1.5, except for the change in the prototype for
+png_get_iCCP() and png_set_iCCP() API functions mentioned above.
+
+libpng 1.5.0 adds PNG_ PASS macros to help in the reading and writing of
+interlaced images. The macros return the number of rows and columns in
+each pass and information that can be used to de-interlace and (if
+absolutely necessary) interlace an image.
+
+libpng 1.5.0 adds an API png_longjmp(png_ptr, value). This API calls
+the application-provided png_longjmp_ptr on the internal, but application
+initialized, longjmp buffer. It is provided as a convenience to avoid
+the need to use the png_jmpbuf macro, which had the unnecessary side
+effect of resetting the internal png_longjmp_ptr value.
+
+libpng 1.5.0 includes a complete fixed point API. By default this is
+present along with the corresponding floating point API. In general the
+fixed point API is faster and smaller than the floating point one because
+the PNG file format used fixed point, not floating point. This applies
+even if the library uses floating point in internal calculations. A new
+macro, PNG_FLOATING_ARITHMETIC_SUPPORTED, reveals whether the library
+uses floating point arithmetic (the default) or fixed point arithmetic
+internally for performance critical calculations such as gamma correction.
+In some cases, the gamma calculations may produce slightly different
+results. This has changed the results in png_rgb_to_gray and in alpha
+composition (png_set_background for example). This applies even if the
+original image was already linear (gamma == 1.0) and, therefore, it is
+not necessary to linearize the image. This is because libpng has *not*
+been changed to optimize that case correctly, yet.
+
+Fixed point support for the sCAL chunk comes with an important caveat;
+the sCAL specification uses a decimal encoding of floating point values
+and the accuracy of PNG fixed point values is insufficient for
+representation of these values. Consequently a "string" API
+(png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading
+arbitrary sCAL chunks in the absence of either the floating point API or
+internal floating point calculations. Starting with libpng-1.5.0, both
+of these functions are present when PNG_sCAL_SUPPORTED is defined. Prior
+to libpng-1.5.0, their presence also depended upon PNG_FIXED_POINT_SUPPORTED
+being defined and PNG_FLOATING_POINT_SUPPORTED not being defined.
+
+Applications no longer need to include the optional distribution header
+file pngusr.h or define the corresponding macros during application
+build in order to see the correct variant of the libpng API. From 1.5.0
+application code can check for the corresponding _SUPPORTED macro:
+
+#ifdef PNG_INCH_CONVERSIONS_SUPPORTED
+ /* code that uses the inch conversion APIs. */
+#endif
+
+This macro will only be defined if the inch conversion functions have been
+compiled into libpng. The full set of macros, and whether or not support
+has been compiled in, are available in the header file pnglibconf.h.
+This header file is specific to the libpng build. Notice that prior to
+1.5.0 the _SUPPORTED macros would always have the default definition unless
+reset by pngusr.h or by explicit settings on the compiler command line.
+These settings may produce compiler warnings or errors in 1.5.0 because
+of macro redefinition.
+
+Applications can now choose whether to use these macros or to call the
+corresponding function by defining PNG_USE_READ_MACROS or
+PNG_NO_USE_READ_MACROS before including png.h. Notice that this is
+only supported from 1.5.0; defining PNG_NO_USE_READ_MACROS prior to 1.5.0
+will lead to a link failure.
+
+Prior to libpng-1.5.4, the zlib compressor used the same set of parameters
+when compressing the IDAT data and textual data such as zTXt and iCCP.
+In libpng-1.5.4 we reinitialized the zlib stream for each type of data.
+We added five png_set_text_*() functions for setting the parameters to
+use with textual data.
+
+Prior to libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+option was off by default, and slightly inaccurate scaling occurred.
+This option can no longer be turned off, and the choice of accurate
+or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8()
+API for accurate scaling or the old png_set_strip_16_to_8() API for simple
+chopping. In libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+macro became PNG_READ_SCALE_16_TO_8_SUPPORTED, and the PNG_READ_16_TO_8
+macro became PNG_READ_STRIP_16_TO_8_SUPPORTED, to enable the two
+png_set_*_16_to_8() functions separately.
+
+Prior to libpng-1.5.4, the png_set_user_limits() function could only be
+used to reduce the width and height limits from the value of
+PNG_USER_WIDTH_MAX and PNG_USER_HEIGHT_MAX, although this document said
+that it could be used to override them. Now this function will reduce or
+increase the limits.
+
+Starting in libpng-1.5.22, default user limits were established. These
+can be overridden by application calls to png_set_user_limits(),
+png_set_user_chunk_cache_max(), and/or png_set_user_malloc_max().
+The limits are now
+ max possible default
+ png_user_width_max 0x7fffffff 1,000,000
+ png_user_height_max 0x7fffffff 1,000,000
+ png_user_chunk_cache_max 0 (unlimited) 1000
+ png_user_chunk_malloc_max 0 (unlimited) 8,000,000
+
+The png_set_option() function (and the "options" member of the png struct) was
+added to libpng-1.5.15, with option PNG_ARM_NEON.
+
+The library now supports a complete fixed point implementation and can
+thus be used on systems that have no floating point support or very
+limited or slow support. Previously gamma correction, an essential part
+of complete PNG support, required reasonably fast floating point.
+
+As part of this the choice of internal implementation has been made
+independent of the choice of fixed versus floating point APIs and all the
+missing fixed point APIs have been implemented.
+
+The exact mechanism used to control attributes of API functions has
+changed, as described in the INSTALL file.
+
+A new test program, pngvalid, is provided in addition to pngtest.
+pngvalid validates the arithmetic accuracy of the gamma correction
+calculations and includes a number of validations of the file format.
+A subset of the full range of tests is run when "make check" is done
+(in the 'configure' build.) pngvalid also allows total allocated memory
+usage to be evaluated and performs additional memory overwrite validation.
+
+Many changes to individual feature macros have been made. The following
+are the changes most likely to be noticed by library builders who
+configure libpng:
+
+1) All feature macros now have consistent naming:
+
+#define PNG_NO_feature turns the feature off
+#define PNG_feature_SUPPORTED turns the feature on
+
+pnglibconf.h contains one line for each feature macro which is either:
+
+#define PNG_feature_SUPPORTED
+
+if the feature is supported or:
+
+/*#undef PNG_feature_SUPPORTED*/
+
+if it is not. Library code consistently checks for the 'SUPPORTED' macro.
+It does not, and libpng applications should not, check for the 'NO' macro
+which will not normally be defined even if the feature is not supported.
+The 'NO' macros are only used internally for setting or not setting the
+corresponding 'SUPPORTED' macros.
+
+Compatibility with the old names is provided as follows:
+
+PNG_INCH_CONVERSIONS turns on PNG_INCH_CONVERSIONS_SUPPORTED
+
+And the following definitions disable the corresponding feature:
+
+PNG_SETJMP_NOT_SUPPORTED disables SETJMP
+PNG_READ_TRANSFORMS_NOT_SUPPORTED disables READ_TRANSFORMS
+PNG_NO_READ_COMPOSITED_NODIV disables READ_COMPOSITE_NODIV
+PNG_WRITE_TRANSFORMS_NOT_SUPPORTED disables WRITE_TRANSFORMS
+PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED disables READ_ANCILLARY_CHUNKS
+PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED disables WRITE_ANCILLARY_CHUNKS
+
+Library builders should remove use of the above, inconsistent, names.
+
+2) Warning and error message formatting was previously conditional on
+the STDIO feature. The library has been changed to use the
+CONSOLE_IO feature instead. This means that if CONSOLE_IO is disabled
+the library no longer uses the printf(3) functions, even though the
+default read/write implementations use (FILE) style stdio.h functions.
+
+3) Three feature macros now control the fixed/floating point decisions:
+
+PNG_FLOATING_POINT_SUPPORTED enables the floating point APIs
+
+PNG_FIXED_POINT_SUPPORTED enables the fixed point APIs; however, in
+practice these are normally required internally anyway (because the PNG
+file format is fixed point), therefore in most cases PNG_NO_FIXED_POINT
+merely stops the function from being exported.
+
+PNG_FLOATING_ARITHMETIC_SUPPORTED chooses between the internal floating
+point implementation or the fixed point one. Typically the fixed point
+implementation is larger and slower than the floating point implementation
+on a system that supports floating point; however, it may be faster on a
+system which lacks floating point hardware and therefore uses a software
+emulation.
+
+4) Added PNG_{READ,WRITE}_INT_FUNCTIONS_SUPPORTED. This allows the
+functions to read and write ints to be disabled independently of
+PNG_USE_READ_MACROS, which allows libpng to be built with the functions
+even though the default is to use the macros - this allows applications
+to choose at app buildtime whether or not to use macros (previously
+impossible because the functions weren't in the default build.)
+
+.SH XII. Changes to Libpng from version 1.5.x to 1.6.x
+
+A "simplified API" has been added (see documentation in png.h and a simple
+example in contrib/examples/pngtopng.c). The new publicly visible API
+includes the following:
+
+ macros:
+ PNG_FORMAT_*
+ PNG_IMAGE_*
+ structures:
+ png_control
+ png_image
+ read functions
+ png_image_begin_read_from_file()
+ png_image_begin_read_from_stdio()
+ png_image_begin_read_from_memory()
+ png_image_finish_read()
+ png_image_free()
+ write functions
+ png_image_write_to_file()
+ png_image_write_to_memory()
+ png_image_write_to_stdio()
+
+Starting with libpng-1.6.0, you can configure libpng to prefix all exported
+symbols, using the PNG_PREFIX macro.
+
+We no longer include string.h in png.h. The include statement has been moved
+to pngpriv.h, where it is not accessible by applications. Applications that
+need access to information in string.h must add an '#include <string.h>'
+directive. It does not matter whether this is placed prior to or after
+the '#include "png.h"' directive.
+
+The following API are now DEPRECATED:
+ png_info_init_3()
+ png_convert_to_rfc1123() which has been replaced
+ with png_convert_to_rfc1123_buffer()
+ png_malloc_default()
+ png_free_default()
+ png_reset_zstream()
+
+The following have been removed:
+ png_get_io_chunk_name(), which has been replaced
+ with png_get_io_chunk_type(). The new
+ function returns a 32-bit integer instead of
+ a string.
+ The png_sizeof(), png_strlen(), png_memcpy(), png_memcmp(), and
+ png_memset() macros are no longer used in the libpng sources and
+ have been removed. These had already been made invisible to applications
+ (i.e., defined in the private pngpriv.h header file) since libpng-1.5.0.
+
+The signatures of many exported functions were changed, such that
+ png_structp became png_structrp or png_const_structrp
+ png_infop became png_inforp or png_const_inforp
+where "rp" indicates a "restricted pointer".
+
+Dropped support for 16-bit platforms. The support for FAR/far types has
+been eliminated and the definition of png_alloc_size_t is now controlled
+by a flag so that 'small size_t' systems can select it if necessary.
+
+Error detection in some chunks has improved; in particular the iCCP chunk
+reader now does pretty complete validation of the basic format. Some bad
+profiles that were previously accepted are now accepted with a warning or
+rejected, depending upon the png_set_benign_errors() setting, in particular
+the very old broken Microsoft/HP 3144-byte sRGB profile. Starting with
+libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
+means of
+
+ #if defined(PNG_SKIP_sRGB_CHECK_PROFILE) && \
+ defined(PNG_SET_OPTION_SUPPORTED)
+ png_set_option(png_ptr, PNG_SKIP_sRGB_CHECK_PROFILE,
+ PNG_OPTION_ON);
+ #endif
+
+It's not a good idea to do this if you are using the "simplified API",
+which needs to be able to recognize sRGB profiles conveyed via the iCCP
+chunk.
+
+The PNG spec requirement that only grayscale profiles may appear in images
+with color type 0 or 4 and that even if the image only contains gray pixels,
+only RGB profiles may appear in images with color type 2, 3, or 6, is now
+enforced. The sRGB chunk is allowed to appear in images with any color type
+and is interpreted by libpng to convey a one-tracer-curve gray profile or a
+three-tracer-curve RGB profile as appropriate.
+
+Libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used the debug
+builds in your app and you changed your app to use /MD you will need to
+change it back to /MDd for libpng 1.6.x.
+
+Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
+an empty language field or an empty translated keyword. Both of these
+are allowed by the PNG specification, so these warnings are no longer issued.
+
+The library now issues an error if the application attempts to set a
+transform after it calls png_read_update_info() or if it attempts to call
+both png_read_update_info() and png_start_read_image() or to call either
+of them more than once.
+
+The default condition for benign_errors is now to treat benign errors as
+warnings while reading and as errors while writing.
+
+The library now issues a warning if both background processing and RGB to
+gray are used when gamma correction happens. As with previous versions of
+the library the results are numerically very incorrect in this case.
+
+There are some minor arithmetic changes in some transforms such as
+png_set_background(), that might be detected by certain regression tests.
+
+Unknown chunk handling has been improved internally, without any API change.
+This adds more correct option control of the unknown handling, corrects
+a pre-existing bug where the per-chunk 'keep' setting is ignored, and makes
+it possible to skip IDAT chunks in the sequential reader.
+
+The machine-generated configure files are no longer included in branches
+libpng16 and later of the GIT repository. They continue to be included
+in the tarball releases, however.
+
+Libpng-1.6.0 through 1.6.2 used the CMF bytes at the beginning of the IDAT
+stream to set the size of the sliding window for reading instead of using the
+default 32-kbyte sliding window size. It was discovered that there are
+hundreds of PNG files in the wild that have incorrect CMF bytes that caused
+zlib to issue the "invalid distance too far back" error and reject the file.
+Libpng-1.6.3 and later calculate their own safe CMF from the image dimensions,
+provide a way to revert to the libpng-1.5.x behavior (ignoring the CMF bytes
+and using a 32-kbyte sliding window), by using
+
+ png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
+ PNG_OPTION_ON);
+
+and provide a tool (contrib/tools/pngfix) for rewriting a PNG file while
+optimizing the CMF bytes in its IDAT chunk correctly.
+
+Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
+length, which resulted in PNG files that cannot be read beyond the bad iTXt
+chunk. This error was fixed in libpng-1.6.3, and a tool (called
+contrib/tools/png-fix-itxt) has been added to the libpng distribution.
+
+Starting with libpng-1.6.17, the PNG_SAFE_LIMITS macro was eliminated
+and safe limits are used by default (users who need larger limits
+can still override them at compile time or run time, as described above).
+
+The new limits are
+ default spec limit
+ png_user_width_max 1,000,000 2,147,483,647
+ png_user_height_max 1,000,000 2,147,483,647
+ png_user_chunk_cache_max 128 unlimited
+ png_user_chunk_malloc_max 8,000,000 unlimited
+
+Starting with libpng-1.6.18, a PNG_RELEASE_BUILD macro was added, which allows
+library builders to control compilation for an installed system (a release build).
+It can be set for testing debug or beta builds to ensure that they will compile
+when the build type is switched to RC or STABLE. In essence this overrides the
+PNG_LIBPNG_BUILD_BASE_TYPE definition which is not directly user controllable.
+
+Starting with libpng-1.6.19, attempting to set an over-length PLTE chunk
+is an error. Previously this requirement of the PNG specification was not
+enforced, and the palette was always limited to 256 entries. An over-length
+PLTE chunk found in an input PNG is silently truncated.
+
+Starting with libpng-1.6.31, the eXIf chunk is supported. Libpng does not
+attempt to decode the Exif profile; it simply returns a byte array
+containing the profile to the calling application which must do its own
+decoding.
+
+.SH XIII. Detecting libpng
The png_get_io_ptr() function has been present since libpng-0.88, has never
changed, and is unaffected by conditional compilation macros. It is the
@@ -3871,28 +5760,39 @@ libpng version since 0.88. In an autoconf "configure.in" you could use
AC_CHECK_LIB(png, png_get_io_ptr, ...
-.SH XI. Source code repository
+.SH XV. Source code repository
Since about February 2009, version 1.2.34, libpng has been under "git" source
control. The git repository was built from old libpng-x.y.z.tar.gz files
going back to version 0.70. You can access the git repository (read only)
at
- git://libpng.git.sourceforge.net/gitroot/libpng
+ https://github.com/glennrp/libpng or
+ https://git.code.sf.net/p/libpng/code.git
+
+or you can browse it with a web browser at
-or you can browse it via "gitweb" at
+ https://github.com/glennrp/libpng or
+ https://sourceforge.net/p/libpng/code/ci/libpng16/tree/
- http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng
+Patches can be sent to png-mng-implement at lists.sourceforge.net or
+uploaded to the libpng bug tracker at
-Patches can be sent to glennrp at users.sourceforge.net or to
-png-mng-implement at lists.sourceforge.net or you can upload them to
-the libpng bug tracker at
+ https://libpng.sourceforge.io/
- http://libpng.sourceforge.net
+or as a "pull request" to
-.SH XII. Coding style
+ https://github.com/glennrp/libpng/pulls
-Our coding style is similar to the "Allman" style, with curly
+We also accept patches built from the tar or zip distributions, and
+simple verbal descriptions of bug fixes, reported either to the
+SourceForge bug tracker, to the png-mng-implement at lists.sf.net
+mailing list, as github issues.
+
+.SH XV. Coding style
+
+Our coding style is similar to the "Allman" style
+(See https://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
braces on separate lines:
if (condition)
@@ -3908,7 +5808,7 @@ braces on separate lines:
The braces can be omitted from simple one-line actions:
if (condition)
- return (0);
+ return 0;
We use 3-space indentation, except for continued statements which
are usually indented the same as the first line of the statement
@@ -3929,12 +5829,12 @@ the statement that follows the comment:
/* Single-line comment */
statement;
- /* Multiple-line
- * comment
+ /* This is a multiple-line
+ * comment.
*/
statement;
-Very short comments can be placed at the end of the statement
+Very short comments can be placed after the end of the statement
to which they pertain:
statement; /* comment */
@@ -3947,7 +5847,7 @@ Functions and their curly braces are not indented, and
exported functions are marked with PNGAPI:
/* This is a public function that is visible to
- * application programers. It does thus-and-so.
+ * application programmers. It does thus-and-so.
*/
void PNGAPI
png_exported_function(png_ptr, png_info, foo)
@@ -3955,6 +5855,9 @@ exported functions are marked with PNGAPI:
body;
}
+The return type and decorations are placed on a separate line
+ahead of the function name, as illustrated above.
+
The prototypes for all exported functions appear in png.h,
above the comment that says
@@ -3969,90 +5872,60 @@ We mark all non-exported functions with "/* PRIVATE */"":
}
The prototypes for non-exported functions (except for those in
-pngtest) appear in
-the PNG_INTERNAL section of png.h
-above the comment that says
+pngtest) appear in pngpriv.h above the comment that says
- /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
+ /* Maintainer: Put new private prototypes here ^ */
-The names of all exported functions and variables begin
-with "png_", and all publicly visibl