1 CHANGES - changes for libpng
4 added reader into png.h
5 fixed small problems in stub file
8 split up pngwrite.c to several files
11 cleaned up writer, adding a few new tranformations
12 fixed some bugs in writer
13 interfaced with zlib 0.5
15 added check for 64 KB blocks for 16 bit machines
17 cleaned up code and commented code
18 simplified time handling into png_time
19 created png_color_16 and png_color_8 to handle color needs
20 cleaned up color type defines
22 made various names more consistant
23 interfaced with zlib 0.71
24 cleaned up zTXt reader and writer (using zlib's Reset functions)
25 split transformations into pngrtran.c and pngwtran.c
27 interfaced with zlib 0.8
28 fixed many reading and writing bugs
29 saved using 3 spaces instead of tabs
31 added png_large_malloc() and png_large_free()
33 cleaned up some compiler warnings
34 added png_start_read_image()
36 cleaned up lots of bugs
37 finished dithering and other stuff
39 changed name from pnglib to libpng
40 version 0.71 [June, 1995]
41 changed pngtest.png for zlib 0.93
42 fixed error in libpng.txt and example.c
45 added png_set_filler()
46 split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
47 added #define's to remove unwanted code
48 moved png_info_init() to png.c
49 added old_size into png_realloc()
50 added functions to manually set filtering and compression info
51 changed compression parameters based on image type
52 optimized filter selection code
54 changed external functions passing floats to doubles (k&r problems?)
55 put all the configurable stuff in pngconf.h
56 enabled png_set_shift to work with paletted images on read
57 added png_read_update_info() - updates info structure with
59 version 0.81 [August, 1995]
60 incorporated Tim Wegner's medium model code (thanks, Tim)
61 version 0.82 [September, 1995]
63 version 0.85 [December, 1995]
64 added more medium model code (almost everything's a far)
65 added i/o, error, and memory callback functions
66 fixed some bugs (16 bit, 4 bit interlaced, etc.)
67 added first run progressive reader (barely tested)
68 version 0.86 [January, 1996]
70 improved documentation
71 version 0.87 [January, 1996]
72 fixed medium model bugs
73 fixed other bugs introduced in 0.85 and 0.86
74 added some minor documentation
75 version 0.88 [January, 1996]
76 fixed progressive bugs
77 replaced tabs with spaces
78 cleaned up documentation
79 added callbacks for read/write and warning/error functions
80 version 0.89 [July, 1996]
81 added new initialization API to make libpng work better with shared libs
82 we now have png_create_read_struct(), png_create_write_struct(),
83 png_create_info_struct(), png_destroy_read_struct(), and
84 png_destroy_write_struct() instead of the separate calls to
85 malloc and png_read_init(), png_info_init(), and png_write_init()
86 changed warning/error callback functions to fix bug - this means you
87 should use the new initialization API if you were using the old
88 png_set_message_fn() calls, and that the old API no longer exists
89 so that people are aware that they need to change their code
90 changed filter selection API to allow selection of multiple filters
91 since it didn't work in previous versions of libpng anyways
92 optimized filter selection code
93 fixed png_set_background() to allow using an arbitrary RGB color for
95 fixed gamma and background correction for paletted images, so
96 png_correct_palette is not needed unless you are correcting an
97 external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
98 in pngconf.h) - if nobody uses this, it may disappear in the future.
99 fixed bug with Borland 64K memory allocation (Alexander Lehmann)
100 fixed bug in interlace handling (Smarasderagd, I think)
101 added more error checking for writing and image to reduce invalid files
102 separated read and write functions so that they won't both be linked
103 into a binary when only reading or writing functionality is used
104 new pngtest image also has interlacing and zTXt
105 updated documentation to reflect new API
106 version 0.90 [January, 1997]
107 made CRC errors/warnings on critical and ancillary chunks configurable
108 libpng will use the zlib CRC routines by (compile-time) default
109 changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
110 added external C++ wrapper statements to png.h (Gilles Dauphin)
111 allow PNG file to be read when some or all of file signature has already
112 been read from the beginning of the stream. ****This affects the size
113 of info_struct and invalidates all programs that use a shared libpng****
114 fixed png_filler() declarations
115 fixed? background color conversions
116 fixed order of error function pointers to match documentation
117 current chunk name is now available in png_struct to reduce the number
118 of nearly identical error messages (will simplify multi-lingual
119 support when available)
120 try to get ready for unknown-chunk callback functions:
121 - previously read critical chunks are flagged, so the chunk handling
122 routines can determine if the chunk is in the right place
123 - all chunk handling routines have the same prototypes, so we will
124 be able to handle all chunks via a callback mechanism
125 try to fix Linux "setjmp" buffer size problems
126 version 0.95 [March, 1997]
127 fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
128 fixed bug in PNG file signature compares when start != 0
129 changed parameter type of png_set_filler(...filler...) from png_byte
131 added test for MACOS to ensure that both math.h and fp.h are not #included
132 added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
133 added "packswap" transformation, which changes the endianness of
134 packed-pixel bytes (Kevin Bracey)
135 added "strip_alpha" transformation, which removes the alpha channel of
136 input images without using it (not neccesarily a good idea)
137 added "swap_alpha" transformation, which puts the alpha channel in front
138 of the color bytes instead of after
139 removed all implicit variable tests which assume NULL == 0 (I think)
140 changed several variables to "png_size_t" to show 16/32-bit limitations
141 added new pCAL chunk read/write support
142 added experimental filter selection weighting (Greg Roelofs)
143 removed old png_set_rgbx() and png_set_xrgb() functions that have been
144 obsolete for about 2 years now (use png_set_filler() instead)
145 added macros to read 16- and 32-bit ints directly from buffer, to be
146 used only on those systems that support it (namely PowerPC and 680x0)
147 With some testing, this may become the default for MACOS/PPC systems.
148 only calculate CRC on data if we are going to use it
149 added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
150 added macros for simple libpng debugging output selectable at compile time
151 removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
152 more description of info_struct in libpng.txt and png.h
153 more instructions in example.c
154 more chunk types tested in pngtest.c
155 renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
156 png_set_<chunk>. We now have corresponding png_get_<chunk>
157 functions in pngget.c to get infomation in info_ptr. This isolates
158 the application from the internal organization of png_info_struct
159 (good for shared library implementations).
160 version 0.96 [May, 1997]
161 fixed serious bug with < 8bpp images introduced in 0.95
162 fixed 256-color transparency bug (Greg Roelofs)
163 fixed up documentation (Greg Roelofs, Laszlo Nyul)
164 fixed "error" in pngconf.h for Linux setjmp() behaviour
165 fixed DOS medium model support (Tim Wegner)
166 fixed png_check_keyword() for case with error in static string text
167 added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
168 added typecasts to quiet compiler errors
169 added more debugging info
170 version 0.97 [January, 1998]
171 removed PNG_USE_OWN_CRC capability
172 relocated png_set_crc_action from pngrutil.c to pngrtran.c
173 fixed typecasts of "new_key", etc. (Andreas Dilger)
174 added RFC 1152 [sic] date support
175 fixed bug in gamma handling of 4-bit grayscale
176 added 2-bit grayscale gamma handling (Glenn R-P)
177 added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
178 minor corrections in libpng.txt
179 added simple sRGB support (Glenn R-P)
180 easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
181 all configurable options can be selected from command-line instead
182 of having to edit pngconf.h (Glenn R-P)
183 fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
184 added more conditions for png_do_background, to avoid changing
185 black pixels to background when a background is supplied and
186 no pixels are transparent
187 repaired PNG_NO_STDIO behaviour
188 tested NODIV support and made it default behaviour (Greg Roelofs)
189 added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
190 regularized version numbering scheme and bumped shared-library major
191 version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
192 version 0.98 [January, 1998]
193 cleaned up some typos in libpng.txt and in code documentation
194 fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
195 cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
196 changed recommendation about file_gamma for PC images to .51 from .45,
197 in example.c and libpng.txt, added comments to distinguish between
198 screen_gamma, viewing_gamma, and display_gamma.
199 changed all references to RFC1152 to read RFC1123 and changed the
200 PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
201 added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
202 changed srgb_intent from png_byte to int to avoid compiler bugs
203 version 0.99 [January 30, 1998]
204 free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
205 fixed a longstanding "packswap" bug in pngtrans.c
206 fixed some inconsistencies in pngconf.h that prevented compiling with
207 PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
208 fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
209 changed recommendation about file_gamma for PC images to .50 from .51 in
210 example.c and libpng.txt, and changed file_gamma for sRGB images to .45
211 added a number of functions to access information from the png structure
212 png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
213 added TARGET_MACOS similar to zlib-1.0.8
214 define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
215 added type casting to all png_malloc() function calls
216 version 0.99a [January 31, 1998]
217 Added type casts and parentheses to all returns that return a value.(Tim W.)
218 version 0.99b [February 4, 1998]
219 Added type cast png_uint_32 on malloc function calls where needed.
220 Changed type of num_hist from png_uint_32 to int (same as num_palette).
221 Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
222 Renamed makefile.elf to makefile.lnx.
223 version 0.99c [February 7, 1998]
224 More type casting. Removed erroneous overflow test in pngmem.c.
225 Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
226 Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5.
227 version 0.99d [February 11, 1998]
228 Renamed "far_to_near()" "png_far_to_near()"
230 Version 99c "buffered" operations didn't work as intended. Replaced them
231 with png_memcpy_check() and png_memset_check().
232 Added many "if (png_ptr == NULL) return" to quell compiler warnings about
233 unused png_ptr, mostly in pngget.c and pngset.c.
234 Check for overlength tRNS chunk present when indexed-color PLTE is read.
235 Cleaned up spelling errors in libpng.3/libpng.txt
236 Corrected a problem with png_get_tRNS() which returned undefined trans array
237 version 0.99e [February 28, 1998]
238 Corrected png_get_tRNS() again.
239 Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
240 Touched up example.c to make more of it compileable, although the entire
241 file still can't be compiled (Willem van Schaik)
242 Fixed a bug in png_do_shift() (Bryan Tsai)
243 Added a space in png.h prototype for png_write_chunk_start()
244 Replaced pngtest.png with one created with zlib 1.1.1
245 Changed pngtest to report PASS even when file size is different (Jean-loup G.)
246 Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
247 version 0.99f [March 5, 1998]
248 Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
249 Moved makefiles into a "scripts" directory, and added INSTALL instruction file
250 Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
251 Added pointers to "note on libpng versions" in makefile.lnx and README
252 Added row callback feature when reading and writing nonprogressive rows
253 and added a test of this feature in pngtest.c
254 Added user transform callbacks, with test of the feature in pngtest.c
255 version 0.99g [March 6, 1998, morning]
256 Minor changes to pngtest.c to suppress compiler warnings.
257 Removed "beta" language from documentation.
258 version 0.99h [March 6, 1998, evening]
259 Minor changes to previous minor changes to pngtest.c
260 Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
261 and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
262 version 1.00 [March 7, 1998]
263 Changed several typedefs in pngrutil.c
264 Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
265 replaced "while(1)" with "for(;;)"
266 added PNGARG() to prototypes in pngtest.c and removed some prototypes
267 updated some of the makefiles (Tom Lane)
268 changed some typedefs (s_start, etc.) in pngrutil.c
269 fixed dimensions of "short_months" array in pngwrite.c
270 Replaced ansi2knr.c with the one from jpeg-v6
271 version 1.0.0 [March 8, 1998]
272 Changed name from 1.00 to 1.0.0 (Adam Costello)
273 Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
274 version 1.0.0a [March 9, 1998]
275 Fixed three bugs in pngrtran.c to make gamma+background handling consistent
277 Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
278 for major, minor, and bugfix releases. This is 10001. (Adam Costello,
280 Make months range from 1-12 in png_convert_to_rfc1123
281 version 1.0.0b [March 13, 1998]
282 Quieted compiler complaints about two empty "for" loops in pngrutil.c
283 Minor changes to makefile.s2x
284 Removed #ifdef/#endif around a png_free() in pngread.c
285 version 1.0.1 [March 14, 1998]
286 Changed makefile.s2x to reduce security risk of using a relative pathname
287 Fixed some typos in the documentation (Greg).
288 Fixed a problem with value of "channels" returned by png_read_update_info()
289 version 1.0.1a [April 21, 1998]
290 Optimized Paeth calculations by replacing abs() function calls with intrinsics
291 plus other loop optimizations. Improves avg decoding speed by about 20%.
292 Commented out i386istic "align" compiler flags in makefile.lnx.
293 Reduced the default warning level in some makefiles, to make them consistent.
294 Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
295 Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
296 Added grayscale and 16-bit capability to png_do_read_filler().
297 Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
298 too large when writing an image with bit_depth < 8 (Bob Dellaca).
299 Corrected some bugs in the experimental weighted filtering heuristics.
300 Moved a misplaced pngrutil code block that truncates tRNS if it has more
301 than num_palette entries -- test was done before num_palette was defined.
302 Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
303 Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
304 version 1.0.1b [May 2, 1998]
305 Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
306 Relocated the png_composite macros from pngrtran.c to png.h (Greg).
307 Added makefile.sco (contributed by Mike Hopkirk).
308 Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
309 Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
310 More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
311 More work on loop optimization which may help when compiled with C++ compilers.
312 Added warnings when people try to use transforms they've defined out.
313 Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
314 Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
315 version 1.0.1c [May 11, 1998]
316 Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
317 filler bytes should have been 0xff instead of 0xf.
318 Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
319 Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
320 out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
321 Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
322 for consistency, in pngconf.h
323 Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
324 to remove unwanted capabilities via the compile line
325 Made some corrections to grammar (which, it's) in documentation (Greg).
326 Corrected example.c, use of row_pointers in png_write_image().
327 version 1.0.1d [May 24, 1998]
328 Corrected several statements that used side effects illegally in pngrutil.c
329 and pngtrans.c, that were introduced in version 1.0.1b
330 Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
331 More corrections to example.c, use of row_pointers in png_write_image()
333 Added pngdll.mak and pngdef.pas to scripts directory, contributed by
334 Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
335 Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
336 Changed several loops from count-down to count-up, for consistency.
337 version 1.0.1e [June 6, 1998]
338 Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
339 added warnings when people try to set png_read_fn and png_write_fn in
341 Added a test such that png_do_gamma will be done when num_trans==0
342 for truecolor images that have defined a background. This corrects an
343 error that was introduced in libpng-0.90 that can cause gamma processing
345 Added tests in png.h to include "trans" and "trans_values" in structures
346 when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
347 Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
348 Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
349 Added capability for user-provided malloc_fn() and free_fn() functions,
350 and revised pngtest.c to demonstrate their use, replacing the
351 PNGTEST_DEBUG_MEM feature.
352 Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
353 version 1.0.2 [June 14, 1998]
354 Fixed two bugs in makefile.bor .
355 version 1.0.2a [December 30, 1998]
356 Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
357 Fixed a bug in png_do_filler() that made it fail to write filler bytes in
358 the left-most pixel of each row (Kevin Bracey).
359 Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
360 in pngtest.c (Duncan Simpson).
361 Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
362 even when no tIME chunk was present in the source file.
363 Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
364 Fixed a problem in png_read_push_finish_row(), which would not skip some
365 passes that it should skip, for images that are less than 3 pixels high.
366 Interchanged the order of calls to png_do_swap() and png_do_shift()
367 in pngwtran.c (John Cromer).
368 Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
369 Changed "bad adaptive filter type" from error to warning in pngrutil.c .
370 Fixed a documentation error about default filtering with 8-bit indexed-color.
371 Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
373 Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
374 Added png_get_copyright() and png_get_header_version() functions.
375 Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
376 Added information about debugging in libpng.txt and libpng.3 .
377 Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
378 Removed lines after Dynamic Dependencies" in makefile.aco .
379 Revised makefile.dec to make a shared library (Jeremie Petit).
380 Removed trailing blanks from all files.
381 version 1.0.2a [January 6, 1999]
382 Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
383 Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
384 Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
385 Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
387 version 1.0.3 [January 14, 1999]
388 Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
389 Added a statement of Y2K compliance in png.h, libpng.1, and Y2KINFO.