dll/3rdparty/libjpeg/change.log

   1 CHANGE LOG for Independent JPEG Group's JPEG software
   2
   3
   4 Version 9c  14-Jan-2018
   5 -----------------------
   6
   7 jpegtran: add an option to the -wipe switch to fill the region
   8 with the average of adjacent blocks, instead of gray out.
   9 Thank to Caitlyn Feddock and Maddie Ziegler for inspiration.
  10
  11 Make range extension bits adjustable (in jpegint.h).
  12 Thank to Robin Watts for suggestion.
  13
  14 Provide macros for fflush() and ferror() in jinclude.h in order
  15 to facilitate adaption by applications using an own FILE class.
  16 Thank to Gerhard Huber for suggestion.
  17
  18 Add libjpeg pkg-config file.  Thank to Mark Lavi, Vincent Torri,
  19 Patrick McMunn, and Huw Davies for suggestion.
  20
  21 Add sanity checks in cjpeg image reader modules.
  22 Thank to Bingchang, Liu for reports.
  23
  24
  25 Version 9b  17-Jan-2016
  26 -----------------------
  27
  28 Improvements and optimizations in DCT and color calculations.
  29 Normalize range limit array composition and access pattern.
  30 Thank to Sia Furler and Maddie Ziegler for inspiration.
  31
  32 Use merged upsample with scaled DCT sizes larger than 8.
  33 Thank to Taylor Hatala for inspiration.
  34
  35 Check for excessive comment lengths in argument parsing in wrjpgcom.c.
  36 Thank to Julian Cohen for hint.
  37
  38 Add makefile.b32 for use with Borland C++ 32-bit (bcc32).
  39 Thank to Joe Slater for contribution.
  40
  41 Document 'f' specifier for jpegtran -crop specification.
  42 Thank to Michele Martone for suggestion.
  43
  44 Use defined value from header instead of hardwired number in rdswitch.c.
  45 Thank to Robert Sprowson for hint.
  46
  47
  48 Version 9a  19-Jan-2014
  49 -----------------------
  50
  51 Add support for wide gamut color spaces (JFIF version 2).
  52 Improve clarity and accuracy in color conversion modules.
  53 Note: Requires rebuild of test images.
  54
  55 Extend the bit depth support to all values from 8 to 12
  56 (BITS_IN_JSAMPLE configuration option in jmorecfg.h).
  57 jpegtran now supports N bits sample data precision with all N from 8 to 12
  58 in a single instance.  Thank to Roland Fassauer for inspiration.
  59
  60 Try to resolve issues with new boolean type definition.
  61 Thank also to v4hn for suggestion.
  62
  63 Enable option to use default Huffman tables for lossless compression
  64 (for hardware solution), and in this case improve lossless RGB compression
  65 with reversible color transform.  Thank to Benny Alexandar for hint.
  66
  67 Extend the entropy decoding structure, so that extraneous bytes between
  68 compressed scan data and following marker can be reported correctly.
  69 Thank to Nigel Tao for hint.
  70
  71 Add jpegtran -wipe option and extension for -crop.
  72 Thank to Andrew Senior, David Clunie, and Josef Schmid for suggestion.
  73
  74
  75 Version 9  13-Jan-2013
  76 ----------------------
  77
  78 Add cjpeg -rgb1 option to create an RGB JPEG file, and insert
  79 a simple reversible color transform into the processing which
  80 significantly improves the compression.
  81 The recommended command for lossless coding of RGB images is now
  82 cjpeg -rgb1 -block 1 -arithmetic.
  83 As said, this option improves the compression significantly, but
  84 the files are not compatible with JPEG decoders prior to IJG v9
  85 due to the included color transform.
  86 The used color transform and marker signaling is compatible with
  87 other JPEG standards (e.g., JPEG-LS part 2).
  88
  89 Remove the automatic de-ANSI-fication support (Automake 1.12).
  90 Thank also to Nitin A Kamble for suggestion.
  91
  92 Add remark for jpeg_mem_dest() in jdatadst.c.
  93 Thank to Elie-Gregoire Khoury for the hint.
  94
  95 Support files with invalid component identifiers (created
  96 by Adobe PDF).  Thank to Robin Watts for the suggestion.
  97
  98 Adapt full buffer case in jcmainct.c for use with scaled DCT.
  99 Thank to Sergii Biloshytskyi for the suggestion.
 100
 101 Add type identifier for declaration of noreturn functions.
 102 Thank to Brett L. Moore for the suggestion.
 103
 104 Correct argument type in format string, avoid compiler warnings.
 105 Thank to Vincent Torri for hint.
 106
 107 Add missing #include directives in configuration checks, avoid
 108 configuration errors.  Thank to John Spencer for the hint.
 109
 110
 111 Version 8d  15-Jan-2012
 112 -----------------------
 113
 114 Add cjpeg -rgb option to create RGB JPEG files.
 115 Using this switch suppresses the conversion from RGB
 116 colorspace input to the default YCbCr JPEG colorspace.
 117 This feature allows true lossless JPEG coding of RGB color images.
 118 The recommended command for this purpose is currently
 119 cjpeg -rgb -block 1 -arithmetic.
 120 SmartScale capable decoder (introduced with IJG JPEG 8) required.
 121 Thank to Michael Koch for the initial suggestion.
 122
 123 Add option to disable the region adjustment in the transupp crop code.
 124 Thank to Jeffrey Friedl for the suggestion.
 125
 126 Thank to Richard Jones and Edd Dawson for various minor corrections.
 127
 128 Thank to Akim Demaille for configure.ac cleanup.
 129
 130
 131 Version 8c  16-Jan-2011
 132 -----------------------
 133
 134 Add option to compression library and cjpeg (-block N) to use
 135 different DCT block size.
 136 All N from 1 to 16 are possible.  Default is 8 (baseline format).
 137 Larger values produce higher compression,
 138 smaller values produce higher quality.
 139 SmartScale capable decoder (introduced with IJG JPEG 8) required.
 140
 141
 142 Version 8b  16-May-2010
 143 -----------------------
 144
 145 Repair problem in new memory source manager with corrupt JPEG data.
 146 Thank to Ted Campbell and Samuel Chun for the report.
 147
 148 Repair problem in Makefile.am test target.
 149 Thank to anonymous user for the report.
 150
 151 Support MinGW installation with automatic configure.
 152 Thank to Volker Grabsch for the suggestion.
 153
 154
 155 Version 8a  28-Feb-2010
 156 -----------------------
 157
 158 Writing tables-only datastreams via jpeg_write_tables works again.
 159
 160 Support 32-bit BMPs (RGB image with Alpha channel) for read in cjpeg.
 161 Thank to Brett Blackham for the suggestion.
 162
 163 Improve accuracy in floating point IDCT calculation.
 164 Thank to Robert Hooke for the hint.
 165
 166
 167 Version 8  10-Jan-2010
 168 ----------------------
 169
 170 jpegtran now supports the same -scale option as djpeg for "lossless" resize.
 171 An implementation of the JPEG SmartScale extension is required for this
 172 feature.  A (draft) specification of the JPEG SmartScale extension is
 173 available as a contributed document at ITU and ISO.  Revision 2 or later
 174 of the document is required (latest document version is Revision 3).
 175 The SmartScale extension will enable more features beside lossless resize
 176 in future implementations, as described in the document (new compression
 177 options).
 178
 179 Add sanity check in BMP reader module to avoid cjpeg crash for empty input
 180 image (thank to Isaev Ildar of ISP RAS, Moscow, RU for reporting this error).
 181
 182 Add data source and destination managers for read from and write to
 183 memory buffers.  New API functions jpeg_mem_src and jpeg_mem_dest.
 184 Thank to Roberto Boni from Italy for the suggestion.
 185
 186
 187 Version 7  27-Jun-2009
 188 ----------------------
 189
 190 New scaled DCTs implemented.
 191 djpeg now supports scalings N/8 with all N from 1 to 16.
 192 cjpeg now supports scalings 8/N with all N from 1 to 16.
 193 Scaled DCTs with size larger than 8 are now also used for resolving the
 194 common 2x2 chroma subsampling case without additional spatial resampling.
 195 Separate spatial resampling for those kind of files is now only necessary
 196 for N>8 scaling cases.
 197 Furthermore, separate scaled DCT functions are provided for direct resolving
 198 of the common asymmetric subsampling cases (2x1 and 1x2) without additional
 199 spatial resampling.
 200
 201 cjpeg -quality option has been extended for support of separate quality
 202 settings for luminance and chrominance (or in general, for every provided
 203 quantization table slot).
 204 New API function jpeg_default_qtables() and q_scale_factor array in library.
 205
 206 Added -nosmooth option to cjpeg, complementary to djpeg.
 207 New variable "do_fancy_downsampling" in library, complement to fancy
 208 upsampling.  Fancy upsampling now uses direct DCT scaling with sizes
 209 larger than 8.  The old method is not reversible and has been removed.
 210
 211 Support arithmetic entropy encoding and decoding.
 212 Added files jaricom.c, jcarith.c, jdarith.c.
 213
 214 Straighten the file structure:
 215 Removed files jidctred.c, jcphuff.c, jchuff.h, jdphuff.c, jdhuff.h.
 216
 217 jpegtran has a new "lossless" cropping feature.
 218
 219 Implement -perfect option in jpegtran, new API function
 220 jtransform_perfect_transform() in transupp. (DP 204_perfect.dpatch)
 221
 222 Better error messages for jpegtran fopen failure.
 223 (DP 203_jpegtran_errmsg.dpatch)
 224
 225 Fix byte order issue with 16bit PPM/PGM files in rdppm.c/wrppm.c:
 226 according to Netpbm, the de facto standard implementation of the PNM formats,
 227 the most significant byte is first. (DP 203_rdppm.dpatch)
 228
 229 Add -raw option to rdjpgcom not to mangle the output.
 230 (DP 205_rdjpgcom_raw.dpatch)
 231
 232 Make rdjpgcom locale aware. (DP 201_rdjpgcom_locale.dpatch)
 233
 234 Add extern "C" to jpeglib.h.
 235 This avoids the need to put extern "C" { ... } around #include "jpeglib.h"
 236 in your C++ application.  Defining the symbol DONT_USE_EXTERN_C in the
 237 configuration prevents this. (DP 202_jpeglib.h_c++.dpatch)
 238
 239
 240 Version 6b  27-Mar-1998
 241 -----------------------
 242
 243 jpegtran has new features for lossless image transformations (rotation
 244 and flipping) as well as "lossless" reduction to grayscale.
 245
 246 jpegtran now copies comments by default; it has a -copy switch to enable
 247 copying all APPn blocks as well, or to suppress comments.  (Formerly it
 248 always suppressed comments and APPn blocks.)  jpegtran now also preserves
 249 JFIF version and resolution information.
 250
 251 New decompressor library feature: COM and APPn markers found in the input
 252 file can be saved in memory for later use by the application.  (Before,
 253 you had to code this up yourself with a custom marker processor.)
 254
 255 There is an unused field "void * client_data" now in compress and decompress
 256 parameter structs; this may be useful in some applications.
 257
 258 JFIF version number information is now saved by the decoder and accepted by
 259 the encoder.  jpegtran uses this to copy the source file's version number,
 260 to ensure "jpegtran -copy all" won't create bogus files that contain JFXX
 261 extensions but claim to be version 1.01.  Applications that generate their
 262 own JFXX extension markers also (finally) have a supported way to cause the
 263 encoder to emit JFIF version number 1.02.
 264
 265 djpeg's trace mode reports JFIF 1.02 thumbnail images as such, rather
 266 than as unknown APP0 markers.
 267
 268 In -verbose mode, djpeg and rdjpgcom will try to print the contents of
 269 APP12 markers as text.  Some digital cameras store useful text information
 270 in APP12 markers.
 271
 272 Handling of truncated data streams is more robust: blocks beyond the one in
 273 which the error occurs will be output as uniform gray, or left unchanged
 274 if decoding a progressive JPEG.  The appearance no longer depends on the
 275 Huffman tables being used.
 276
 277 Huffman tables are checked for validity much more carefully than before.
 278
 279 To avoid the Unisys LZW patent, djpeg's GIF output capability has been
 280 changed to produce "uncompressed GIFs", and cjpeg's GIF input capability
 281 has been removed altogether.  We're not happy about it either, but there
 282 seems to be no good alternative.
 283
 284 The configure script now supports building libjpeg as a shared library
 285 on many flavors of Unix (all the ones that GNU libtool knows how to
 286 build shared libraries for).  Use "./configure --enable-shared" to
 287 try this out.
 288
 289 New jconfig file and makefiles for Microsoft Visual C++ and Developer Studio.
 290 Also, a jconfig file and a build script for Metrowerks CodeWarrior
 291 on Apple Macintosh.  makefile.dj has been updated for DJGPP v2, and there
 292 are miscellaneous other minor improvements in the makefiles.
 293
 294 jmemmac.c now knows how to create temporary files following Mac System 7
 295 conventions.
 296
 297 djpeg's -map switch is now able to read raw-format PPM files reliably.
 298
 299 cjpeg -progressive -restart no longer generates any unnecessary DRI markers.
 300
 301 Multiple calls to jpeg_simple_progression for a single JPEG object
 302 no longer leak memory.
 303
 304
 305 Version 6a  7-Feb-96
 306 --------------------
 307
 308 Library initialization sequence modified to detect version mismatches
 309 and struct field packing mismatches between library and calling application.
 310 This change requires applications to be recompiled, but does not require
 311 any application source code change.
 312
 313 All routine declarations changed to the style "GLOBAL(type) name ...",
 314 that is, GLOBAL, LOCAL, METHODDEF, EXTERN are now macros taking the
 315 routine's return type as an argument.  This makes it possible to add
 316 Microsoft-style linkage keywords to all the routines by changing just
 317 these macros.  Note that any application code that was using these macros
 318 will have to be changed.
 319
 320 DCT coefficient quantization tables are now stored in normal array order
 321 rather than zigzag order.  Application code that calls jpeg_add_quant_table,
 322 or otherwise manipulates quantization tables directly, will need to be
 323 changed.  If you need to make such code work with either older or newer
 324 versions of the library, a test like "#if JPEG_LIB_VERSION >= 61" is
 325 recommended.
 326
 327 djpeg's trace capability now dumps DQT tables in natural order, not zigzag
 328 order.  This allows the trace output to be made into a "-qtables" file
 329 more easily.
 330
 331 New system-dependent memory manager module for use on Apple Macintosh.
 332
 333 Fix bug in cjpeg's -smooth option: last one or two scanlines would be
 334 duplicates of the prior line unless the image height mod 16 was 1 or 2.
 335
 336 Repair minor problems in VMS, BCC, MC6 makefiles.
 337
 338 New configure script based on latest GNU Autoconf.
 339
 340 Correct the list of include files needed by MetroWerks C for ccommand().
 341
 342 Numerous small documentation updates.
 343
 344
 345 Version 6  2-Aug-95
 346 -------------------
 347
 348 Progressive JPEG support: library can read and write full progressive JPEG
 349 files.  A "buffered image" mode supports incremental decoding for on-the-fly
 350 display of progressive images.  Simply recompiling an existing IJG-v5-based
 351 decoder with v6 should allow it to read progressive files, though of course
 352 without any special progressive display.
 353
 354 New "jpegtran" application performs lossless transcoding between different
 355 JPEG formats; primarily, it can be used to convert baseline to progressive
 356 JPEG and vice versa.  In support of jpegtran, the library now allows lossless
 357 reading and writing of JPEG files as DCT coefficient arrays.  This ability
 358 may be of use in other applications.
 359
 360 Notes for programmers:
 361 * We changed jpeg_start_decompress() to be able to suspend; this makes all
 362 decoding modes available to suspending-input applications.  However,
 363 existing applications that use suspending input will need to be changed
 364 to check the return value from jpeg_start_decompress().  You don't need to
 365 do anything if you don't use a suspending data source.
 366 * We changed the interface to the virtual array routines: access_virt_array
 367 routines now take a count of the number of rows to access this time.  The
 368 last parameter to request_virt_array routines is now interpreted as the
 369 maximum number of rows that may be accessed at once, but not necessarily
 370 the height of every access.
 371
 372
 373 Version 5b  15-Mar-95
 374 ---------------------
 375
 376 Correct bugs with grayscale images having v_samp_factor > 1.
 377
 378 jpeg_write_raw_data() now supports output suspension.
 379
 380 Correct bugs in "configure" script for case of compiling in
 381 a directory other than the one containing the source files.
 382
 383 Repair bug in jquant1.c: sometimes didn't use as many colors as it could.
 384
 385 Borland C makefile and jconfig file work under either MS-DOS or OS/2.
 386
 387 Miscellaneous improvements to documentation.
 388
 389
 390 Version 5a  7-Dec-94
 391 --------------------
 392
 393 Changed color conversion roundoff behavior so that grayscale values are
 394 represented exactly.  (This causes test image files to change.)
 395
 396 Make ordered dither use 16x16 instead of 4x4 pattern for a small quality
 397 improvement.
 398
 399 New configure script based on latest GNU Autoconf.
 400 Fix configure script to handle CFLAGS correctly.
 401 Rename *.auto files to *.cfg, so that configure script still works if
 402 file names have been truncated for DOS.
 403
 404 Fix bug in rdbmp.c: didn't allow for extra data between header and image.
 405
 406 Modify rdppm.c/wrppm.c to handle 2-byte raw PPM/PGM formats for 12-bit data.
 407
 408 Fix several bugs in rdrle.c.
 409
 410 NEED_SHORT_EXTERNAL_NAMES option was broken.
 411
 412 Revise jerror.h/jerror.c for more flexibility in message table.
 413
 414 Repair oversight in jmemname.c NO_MKTEMP case: file could be there
 415 but unreadable.
 416
 417
 418 Version 5  24-Sep-94
 419 --------------------
 420
 421 Version 5 represents a nearly complete redesign and rewrite of the IJG
 422 software.  Major user-visible changes include:
 423   * Automatic configuration simplifies installation for most Unix systems.
 424   * A range of speed vs. image quality tradeoffs are supported.
 425     This includes resizing of an image during decompression: scaling down
 426     by a factor of 1/2, 1/4, or 1/8 is handled very efficiently.
 427   * New programs rdjpgcom and wrjpgcom allow insertion and extraction
 428     of text comments in a JPEG file.
 429
 430 The application programmer's interface to the library has changed completely.
 431 Notable improvements include:
 432   * We have eliminated the use of callback routines for handling the
 433     uncompressed image data.  The application now sees the library as a
 434     set of routines that it calls to read or write image data on a
 435     scanline-by-scanline basis.
 436   * The application image data is represented in a conventional interleaved-
 437     pixel format, rather than as a separate array for each color channel.
 438     This can save a copying step in many programs.
 439   * The handling of compressed data has been cleaned up: the application can
 440     supply routines to source or sink the compressed data.  It is possible to
 441     suspend processing on source/sink buffer overrun, although this is not
 442     supported in all operating modes.
 443   * All static state has been eliminated from the library, so that multiple
 444     instances of compression or decompression can be active concurrently.
 445   * JPEG abbreviated datastream formats are supported, ie, quantization and
 446     Huffman tables can be stored separately from the image data.
 447   * And not only that, but the documentation of the library has improved
 448     considerably!
 449
 450
 451 The last widely used release before the version 5 rewrite was version 4A of
 452 18-Feb-93.  Change logs before that point have been discarded, since they
 453 are not of much interest after the rewrite.