version 0.2
added reader into png.h
fixed small problems in stub file
+
version 0.3
added pull reader
split up pngwrite.c to several files
interfaced with zlib 0.5
added K&R support
added check for 64 KB blocks for 16 bit machines
+
version 0.4
cleaned up code and commented code
simplified time handling into png_time
interfaced with zlib 0.71
cleaned up zTXt reader and writer (using zlib's Reset functions)
split transformations into pngrtran.c and pngwtran.c
+
version 0.5
interfaced with zlib 0.8
fixed many reading and writing bugs
saved using 3 spaces instead of tabs
+
version 0.6
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
cleaned up lots of bugs
finished dithering and other stuff
added test program
changed name from pnglib to libpng
+
version 0.71 [June, 1995]
changed pngtest.png for zlib 0.93
fixed error in libpng.txt and example.c
+
version 0.8
cleaned up some bugs
added png_set_filler()
enabled png_set_shift to work with paletted images on read
added png_read_update_info() - updates info structure with
transformations
+
version 0.81 [August, 1995]
incorporated Tim Wegner's medium model code (thanks, Tim)
+
version 0.82 [September, 1995]
[unspecified changes]
+
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.)
added first run progressive reader (barely tested)
+
version 0.86 [January, 1996]
fixed bugs
improved documentation
+
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]
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(),
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
libpng will use the zlib CRC routines by (compile-time) default
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
functions in pngget.c to get infomation 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)
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
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)
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
Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
Added user transform capability
+
version 1.00 [March 7, 1998]
Changed several typedefs in pngrutil.c
Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
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]
Changed name from 1.00 to 1.0.0 (Adam Costello)
Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
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]
Changed makefile.s2x to reduce security risk of using a relative pathname
Fixed some typos in the documentation (Greg).
and revised pngtest.c to demonstrate their use, replacing the
PNGTEST_DEBUG_MEM feature.
Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+
version 1.0.2 [June 14, 1998]
Fixed two bugs in makefile.bor .
version 1.0.2a [December 30, 1998]
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]
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.
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]
Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
Added type casting mostly in pngrtran.c and pngwtran.c
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]
Minor editing of the INSTALL and README files.
version 1.0.5a [October 23, 1999]
Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
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]
Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
Added makefile.sggcc (SGI IRIX with gcc)
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]
Revised the definition of "trans_values" in libpng.3/libpng.txt
version 1.0.8beta1 [July 8, 2000]
Added PNG_NO_ZALLOC_ZERO macro (makes png_zalloc skip zeroing memory)
version 1.0.8rc1 [July 16, 2000]
Revised png_debug() macros and statements to eliminate compiler warnings.
+
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.
be re-enabled in version 1.2.0.
version 1.0.9rc2 [January 22, 2001]
Revised cygwin support.
+
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.
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]
Deleted extraneous space (introduced in 1.0.9) from line 42 of makefile.cygwin
Added beos project files (Chris Herborth)
from user's malloc_fn().
Removed some useless type casts of the NULL pointer.
Added makefile.netbsd
+
version 1.0.11 [April 27, 2001]
Revised makefile.netbsd
version 1.0.12beta1 [May 14, 2001]
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]
Changed a png_warning() to png_debug() in pnggccrd.c
Fixed contrib/gregbook/rpng-x.c, rpng2-x.c to avoid crash with XFreeGC().
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]
None.
version 1.2.2beta1 [February 22, 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]
Revised description of png_set_filter() in libpng.3/libpng.txt.
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]
Revised libpng-config target in makefile.cygwin.
Removed description of png_set_mem_fn() from documentation.
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]
Changed png_warning() to png_error() when width is too large to process.
version 1.2.4patch01 [July 20, 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]
+ 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]
+ 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]
+ 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]
+ 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.
+ Changed the one instance of "ln -sf" to "ln -f -s" in each Sun makefile.
+ Fixed potential overrun in pngerror.c by using strncpy instead of memcpy.
+ Added "#!/bin/sh" at the top of configure, for recognition of the
+ 'x' flag under Cygwin (Cosmin).
+ Optimized vacuous tests that silence compiler warnings, in png.c (Cosmin).
+ Added support for PNG_USER_CONFIG, in pngconf.h (Cosmin).
+ Fixed the special memory handler for Borland C under DOS, in pngmem.c
+ (Cosmin).
+ Removed some spurious assignments in pngrutil.c (Cosmin).
+ Replaced 65536 with 65536L, and 0xffff with 0xffffL, to silence warnings
+ on 16-bit platforms (Cosmin).
+ Enclosed shift op expressions in parentheses, to silence warnings (Cosmin).
+ Used proper type png_fixed_point, to avoid problems on 16-bit platforms,
+ in png_handle_sRGB() (Cosmin).
+ Added compression_type to png_struct, and optimized the window size
+ inside the deflate stream (Cosmin).
+ Fixed definition of isnonalpha(), in pngerror.c and pngrutil.c (Cosmin).
+ Fixed handling of unknown chunks that come after IDAT (Cosmin).
+ Allowed png_error() and png_warning() to work even if png_ptr == NULL
+ (Cosmin).
+ Replaced row_info->rowbytes with row_bytes in png_write_find_filter()
+ (Cosmin).
+ Fixed definition of PNG_LIBPNG_VER_DLLNUM (Simon-Pierre).
+ Used PNG_LIBPNG_VER and PNG_LIBPNG_VER_STRING instead of the hardcoded
+ values in png.c (Simon-Pierre, Cosmin).
+ Initialized png_libpng_ver[] with PNG_LIBPNG_VER_STRING (Simon-Pierre).
+ Replaced PNG_LIBPNG_VER_MAJOR with PNG_LIBPNG_VER_DLLNUM in png.rc
+ (Simon-Pierre).
+ Moved the definition of PNG_HEADER_VERSION_STRING near the definitions
+ of the other PNG_LIBPNG_VER_... symbols in png.h (Cosmin).
+ Relocated #ifndef PNGAPI guards in pngconf.h (Simon-Pierre, Cosmin).
+ Updated scripts/makefile.vc(a)win32 (Cosmin).
+ Updated the MSVC project (Simon-Pierre, Cosmin).
+ Updated the Borland C++ Builder project (Cosmin).
+ Avoided access to asm_flags in pngvcrd.c, if PNG_1_0_X is defined (Cosmin).
+ Commented out warning about uninitialized mmx_support in pngvcrd.c (Cosmin).
+ Removed scripts/makefile.bd32 and scripts/pngdef.pas (Cosmin).
+ Added extra guard around inclusion of Turbo C memory headers, in pngconf.h
+ (Cosmin).
+ Renamed projects/msvc/ to projects/visualc6/, and projects/borland/ to
+ projects/cbuilder5/ (Cosmin).
+ Moved projects/visualc6/png32ms.def to scripts/pngw32.def,
+ and projects/visualc6/png.rc to scripts/pngw32.rc (Cosmin).
+ Added projects/visualc6/pngtest.dsp; removed contrib/msvctest/ (Cosmin).
+ Changed line endings to DOS style in cbuilder5 and visualc6 files, even
+ in the tar.* distributions (Cosmin).
+ 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]
+ 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.
+ Added check in png_malloc_default() for (size_t)size != (png_uint_32)size
+ which would indicate an overflow.
+ Changed sPLT failure action from png_error to png_warning and abandon chunk.
+ Changed sCAL and iCCP failures from png_error to png_warning and abandon.
+ Added png_get_uint_31(png_ptr, buf) function.
+ Added PNG_UINT_32_MAX macro.
+ Renamed PNG_MAX_UINT to PNG_UINT_31_MAX.
+ Made png_zalloc() issue a png_warning and return NULL on potential
+ overflow.
+ Turn on PNG_NO_ZALLOC_ZERO by default in version 1.2.x
+ Revised "clobber list" in pnggccrd.c so it will compile under gcc-3.4.
+ Revised Borland portion of png_malloc() to return NULL or issue
+ png_error() according to setting of PNG_FLAG_MALLOC_NULL_MEM_OK.
+ Added PNG_NO_SEQUENTIAL_READ_SUPPORTED macro to conditionally remove
+ sequential read support.
+ Added some "#if PNG_WRITE_SUPPORTED" blocks.
+ #ifdef'ed out some redundancy 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().
+ 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
+ Rearranged order of processing of color types in png_handle_tRNS().
+ Added ROWBYTES macro to calculate rowbytes without integer overflow.
+ Updated makefile.darwin and removed makefile.macosx from scripts directory.
+ Imposed default one million column, one-million row limits on the image
+ dimensions, and added png_set_user_limits() function to override them.
+ Revised use of PNG_SET_USER_LIMITS_SUPPORTED macro.
+ 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]
+ 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.
+ Fixed off-by-one error in one of the conversions to PNG_ROWBYTES() in
+ pngpread.c. Bug was introduced in 1.2.6rc1.
+ Fixed bug in RGB to RGBX transformation introduced in 1.2.6rc1.
+ Fixed old bug in RGB to Gray transformation.
+ Fixed problem with 64-bit compilers by casting arguments to abs()
+ to png_int_32.
+ Changed "ln -sf" to "ln -f -s" in three makefiles (solaris, sco, so9).
+ 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]
+ 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]
+ 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]
+ Moved "PNG_HANDLE_CHUNK_*" macros out of PNG_ASSEMBLER_CODE_SUPPORTED
+ section of png.h where they were inadvertently placed in version rc3.
+
+version 1.0.16 and 1.2.6 [August 15, 2004]
+ Revised pngtest so memory allocation testing is only done when PNG_DEBUG==1.
+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]
+ 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]
+ Revised png_set_strip_filler() to not remove alpha if color_type has alpha.
+version 1.0.17 and 1.2.7 [September 12, 2004]
+ Added makefile.hp64
+ Changed projects/msvc/png32ms.def to scripts/png32ms.def in makefile.cygwin
+
Send comments/corrections/commendations to
-png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
+png-implement@ccrc.wustl.edu (subscription required; write to
+majordomo@ccrc.wustl.edu with "subscribe png-implement" in the message)
+or to glennrp@users.sourceforge.net
Glenn R-P