blob: b60ddd686c4a52868a50e70a7085c30ec8832d1d [file] [log] [blame]
DRCcf763c02013-01-01 09:51:37 +00001NOTE: This file was modified by The libjpeg-turbo Project to include only
2information relevant to libjpeg-turbo.
3
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +00004CHANGE LOG for Independent JPEG Group's JPEG software
5
6
Guido Vollbeding5829cb22012-01-15 00:00:00 +00007Version 8d 15-Jan-2012
8-----------------------
9
10Add cjpeg -rgb option to create RGB JPEG files.
11Using this switch suppresses the conversion from RGB
12colorspace input to the default YCbCr JPEG colorspace.
Guido Vollbeding5829cb22012-01-15 00:00:00 +000013Thank to Michael Koch for the initial suggestion.
14
Guido Vollbeding5829cb22012-01-15 00:00:00 +000015Add option to disable the region adjustment in the transupp crop code.
16Thank to Jeffrey Friedl for the suggestion.
17
Guido Vollbedingc39ec142011-01-16 00:00:00 +000018
Guido Vollbedinga4ecaac2010-05-16 00:00:00 +000019Version 8b 16-May-2010
20-----------------------
21
22Repair problem in new memory source manager with corrupt JPEG data.
23Thank to Ted Campbell and Samuel Chun for the report.
24
Guido Vollbedinga4ecaac2010-05-16 00:00:00 +000025
Guido Vollbedingf18f81b2010-02-28 00:00:00 +000026Version 8a 28-Feb-2010
27-----------------------
28
29Writing tables-only datastreams via jpeg_write_tables works again.
30
31Support 32-bit BMPs (RGB image with Alpha channel) for read in cjpeg.
32Thank to Brett Blackham for the suggestion.
33
Guido Vollbedingf18f81b2010-02-28 00:00:00 +000034
Guido Vollbeding989630f2010-01-10 00:00:00 +000035Version 8 10-Jan-2010
36----------------------
37
Guido Vollbeding989630f2010-01-10 00:00:00 +000038Add sanity check in BMP reader module to avoid cjpeg crash for empty input
39image (thank to Isaev Ildar of ISP RAS, Moscow, RU for reporting this error).
40
41Add data source and destination managers for read from and write to
42memory buffers. New API functions jpeg_mem_src and jpeg_mem_dest.
43Thank to Roberto Boni from Italy for the suggestion.
44
45
Guido Vollbeding5996a252009-06-27 00:00:00 +000046Version 7 27-Jun-2009
47----------------------
48
Guido Vollbeding5996a252009-06-27 00:00:00 +000049New scaled DCTs implemented.
50djpeg now supports scalings N/8 with all N from 1 to 16.
Guido Vollbeding5996a252009-06-27 00:00:00 +000051
Guido Vollbeding5996a252009-06-27 00:00:00 +000052cjpeg -quality option has been extended for support of separate quality
53settings for luminance and chrominance (or in general, for every provided
54quantization table slot).
55New API function jpeg_default_qtables() and q_scale_factor array in library.
56
Guido Vollbeding5996a252009-06-27 00:00:00 +000057Support arithmetic entropy encoding and decoding.
58Added files jaricom.c, jcarith.c, jdarith.c.
59
Guido Vollbeding5996a252009-06-27 00:00:00 +000060jpegtran has a new "lossless" cropping feature.
61
62Implement -perfect option in jpegtran, new API function
63jtransform_perfect_transform() in transupp. (DP 204_perfect.dpatch)
64
65Better error messages for jpegtran fopen failure.
66(DP 203_jpegtran_errmsg.dpatch)
67
68Fix byte order issue with 16bit PPM/PGM files in rdppm.c/wrppm.c:
69according to Netpbm, the de facto standard implementation of the PNM formats,
70the most significant byte is first. (DP 203_rdppm.dpatch)
71
72Add -raw option to rdjpgcom not to mangle the output.
73(DP 205_rdjpgcom_raw.dpatch)
74
75Make rdjpgcom locale aware. (DP 201_rdjpgcom_locale.dpatch)
76
77Add extern "C" to jpeglib.h.
78This avoids the need to put extern "C" { ... } around #include "jpeglib.h"
79in your C++ application. Defining the symbol DONT_USE_EXTERN_C in the
80configuration prevents this. (DP 202_jpeglib.h_c++.dpatch)
81
82
Thomas G. Lane5ead57a1998-03-27 00:00:00 +000083Version 6b 27-Mar-1998
84-----------------------
85
86jpegtran has new features for lossless image transformations (rotation
87and flipping) as well as "lossless" reduction to grayscale.
88
89jpegtran now copies comments by default; it has a -copy switch to enable
90copying all APPn blocks as well, or to suppress comments. (Formerly it
91always suppressed comments and APPn blocks.) jpegtran now also preserves
92JFIF version and resolution information.
93
94New decompressor library feature: COM and APPn markers found in the input
95file can be saved in memory for later use by the application. (Before,
96you had to code this up yourself with a custom marker processor.)
97
98There is an unused field "void * client_data" now in compress and decompress
99parameter structs; this may be useful in some applications.
100
101JFIF version number information is now saved by the decoder and accepted by
102the encoder. jpegtran uses this to copy the source file's version number,
103to ensure "jpegtran -copy all" won't create bogus files that contain JFXX
104extensions but claim to be version 1.01. Applications that generate their
105own JFXX extension markers also (finally) have a supported way to cause the
106encoder to emit JFIF version number 1.02.
107
108djpeg's trace mode reports JFIF 1.02 thumbnail images as such, rather
109than as unknown APP0 markers.
110
111In -verbose mode, djpeg and rdjpgcom will try to print the contents of
112APP12 markers as text. Some digital cameras store useful text information
113in APP12 markers.
114
115Handling of truncated data streams is more robust: blocks beyond the one in
116which the error occurs will be output as uniform gray, or left unchanged
117if decoding a progressive JPEG. The appearance no longer depends on the
118Huffman tables being used.
119
120Huffman tables are checked for validity much more carefully than before.
121
122To avoid the Unisys LZW patent, djpeg's GIF output capability has been
123changed to produce "uncompressed GIFs", and cjpeg's GIF input capability
124has been removed altogether. We're not happy about it either, but there
125seems to be no good alternative.
126
127The configure script now supports building libjpeg as a shared library
128on many flavors of Unix (all the ones that GNU libtool knows how to
129build shared libraries for). Use "./configure --enable-shared" to
130try this out.
131
132New jconfig file and makefiles for Microsoft Visual C++ and Developer Studio.
133Also, a jconfig file and a build script for Metrowerks CodeWarrior
134on Apple Macintosh. makefile.dj has been updated for DJGPP v2, and there
135are miscellaneous other minor improvements in the makefiles.
136
137jmemmac.c now knows how to create temporary files following Mac System 7
138conventions.
139
140djpeg's -map switch is now able to read raw-format PPM files reliably.
141
142cjpeg -progressive -restart no longer generates any unnecessary DRI markers.
143
144Multiple calls to jpeg_simple_progression for a single JPEG object
145no longer leak memory.
146
147
Thomas G. Lane489583f1996-02-07 00:00:00 +0000148Version 6a 7-Feb-96
149--------------------
150
151Library initialization sequence modified to detect version mismatches
152and struct field packing mismatches between library and calling application.
153This change requires applications to be recompiled, but does not require
154any application source code change.
155
156All routine declarations changed to the style "GLOBAL(type) name ...",
157that is, GLOBAL, LOCAL, METHODDEF, EXTERN are now macros taking the
158routine's return type as an argument. This makes it possible to add
159Microsoft-style linkage keywords to all the routines by changing just
160these macros. Note that any application code that was using these macros
161will have to be changed.
162
163DCT coefficient quantization tables are now stored in normal array order
164rather than zigzag order. Application code that calls jpeg_add_quant_table,
165or otherwise manipulates quantization tables directly, will need to be
166changed. If you need to make such code work with either older or newer
167versions of the library, a test like "#if JPEG_LIB_VERSION >= 61" is
168recommended.
169
170djpeg's trace capability now dumps DQT tables in natural order, not zigzag
171order. This allows the trace output to be made into a "-qtables" file
172more easily.
173
174New system-dependent memory manager module for use on Apple Macintosh.
175
176Fix bug in cjpeg's -smooth option: last one or two scanlines would be
177duplicates of the prior line unless the image height mod 16 was 1 or 2.
178
179Repair minor problems in VMS, BCC, MC6 makefiles.
180
181New configure script based on latest GNU Autoconf.
182
183Correct the list of include files needed by MetroWerks C for ccommand().
184
185Numerous small documentation updates.
186
187
Thomas G. Lanebc79e061995-08-02 00:00:00 +0000188Version 6 2-Aug-95
189-------------------
190
191Progressive JPEG support: library can read and write full progressive JPEG
192files. A "buffered image" mode supports incremental decoding for on-the-fly
193display of progressive images. Simply recompiling an existing IJG-v5-based
194decoder with v6 should allow it to read progressive files, though of course
195without any special progressive display.
196
197New "jpegtran" application performs lossless transcoding between different
198JPEG formats; primarily, it can be used to convert baseline to progressive
199JPEG and vice versa. In support of jpegtran, the library now allows lossless
200reading and writing of JPEG files as DCT coefficient arrays. This ability
201may be of use in other applications.
202
203Notes for programmers:
204* We changed jpeg_start_decompress() to be able to suspend; this makes all
205decoding modes available to suspending-input applications. However,
206existing applications that use suspending input will need to be changed
207to check the return value from jpeg_start_decompress(). You don't need to
208do anything if you don't use a suspending data source.
209* We changed the interface to the virtual array routines: access_virt_array
210routines now take a count of the number of rows to access this time. The
211last parameter to request_virt_array routines is now interpreted as the
212maximum number of rows that may be accessed at once, but not necessarily
213the height of every access.
214
215
Thomas G. Lanea8b67c41995-03-15 00:00:00 +0000216Version 5b 15-Mar-95
217---------------------
218
219Correct bugs with grayscale images having v_samp_factor > 1.
220
221jpeg_write_raw_data() now supports output suspension.
222
223Correct bugs in "configure" script for case of compiling in
224a directory other than the one containing the source files.
225
226Repair bug in jquant1.c: sometimes didn't use as many colors as it could.
227
228Borland C makefile and jconfig file work under either MS-DOS or OS/2.
229
230Miscellaneous improvements to documentation.
231
232
Thomas G. Lane9ba2f5e1994-12-07 00:00:00 +0000233Version 5a 7-Dec-94
234--------------------
235
236Changed color conversion roundoff behavior so that grayscale values are
237represented exactly. (This causes test image files to change.)
238
239Make ordered dither use 16x16 instead of 4x4 pattern for a small quality
240improvement.
241
242New configure script based on latest GNU Autoconf.
243Fix configure script to handle CFLAGS correctly.
244Rename *.auto files to *.cfg, so that configure script still works if
245file names have been truncated for DOS.
246
247Fix bug in rdbmp.c: didn't allow for extra data between header and image.
248
249Modify rdppm.c/wrppm.c to handle 2-byte raw PPM/PGM formats for 12-bit data.
250
251Fix several bugs in rdrle.c.
252
253NEED_SHORT_EXTERNAL_NAMES option was broken.
254
255Revise jerror.h/jerror.c for more flexibility in message table.
256
257Repair oversight in jmemname.c NO_MKTEMP case: file could be there
258but unreadable.
259
260
Thomas G. Lane36a4ccc1994-09-24 00:00:00 +0000261Version 5 24-Sep-94
262--------------------
263
264Version 5 represents a nearly complete redesign and rewrite of the IJG
265software. Major user-visible changes include:
266 * Automatic configuration simplifies installation for most Unix systems.
267 * A range of speed vs. image quality tradeoffs are supported.
268 This includes resizing of an image during decompression: scaling down
269 by a factor of 1/2, 1/4, or 1/8 is handled very efficiently.
270 * New programs rdjpgcom and wrjpgcom allow insertion and extraction
271 of text comments in a JPEG file.
272
273The application programmer's interface to the library has changed completely.
274Notable improvements include:
275 * We have eliminated the use of callback routines for handling the
276 uncompressed image data. The application now sees the library as a
277 set of routines that it calls to read or write image data on a
278 scanline-by-scanline basis.
279 * The application image data is represented in a conventional interleaved-
280 pixel format, rather than as a separate array for each color channel.
281 This can save a copying step in many programs.
282 * The handling of compressed data has been cleaned up: the application can
283 supply routines to source or sink the compressed data. It is possible to
284 suspend processing on source/sink buffer overrun, although this is not
285 supported in all operating modes.
286 * All static state has been eliminated from the library, so that multiple
287 instances of compression or decompression can be active concurrently.
288 * JPEG abbreviated datastream formats are supported, ie, quantization and
289 Huffman tables can be stored separately from the image data.
290 * And not only that, but the documentation of the library has improved
291 considerably!
292
293
294The last widely used release before the version 5 rewrite was version 4A of
29518-Feb-93. Change logs before that point have been discarded, since they
296are not of much interest after the rewrite.