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JBIG-KIT revision history ------------------------- Changes in version 2.0 (2008-08-30) Main new features of release 2.0: - This release adds a separate lightweight "T.85" version of the encoder and decoder library (jbig85.c, jbig85.h). This new T.85 library is optimized for embedded low-memory applications, such as printers and fax machines. It implements only the subset of the JBIG standard that is required by the ITU-T T.85 fax profile, namely only a single bit plane (P = 1) and no differential layers (DL = D = HITOLO = SEQ = ILEAVE = SMID = TPDON = DPON = DPON = DPLAST = 0) and some other restrictions (MY = 0, MX < 128). The T.85 library requires only three pixel rows of the uncompressed image to reside in memory at any time. This 3-line buffer has to be allocated by the calling application, therefore the T.85 library will not call any heap management functions such as malloc() or free() itself. - There are also two new example applications pbmtojbg85 and jbgtopbm85 included that provide command-line access to the new T.85 library. (Note to distribution maintainers: there is probably little point in adding pbmtojbg85 and jbgtopbm85 to precompiled JBIG-KIT packages for workstation operating systems, as these two programs do not really provide the end user much additional functionality beyond what pbmtojbg and jbgtopbm already do, which use the full library instead.) Changes to the original full jbig.c library from version 1.6: - the arithmetic codec routines are now located in a separate source file (they are now used by both the full library jbig.c and the new T.85 library jbig85.c, and might also be of use to other applications) - arithmetic decoder behaviour slightly changed to enable the lookahead needed to handle T.85-style NEWLEN after the final stripe - added encoder support for adding comment marker segment - added encoder option for using SDRST marker instead of SDNORM (only useful to make encoder able to generate a wider range of test data) - added pbmtojbg options -C and -r, which provide command-line access to the previous two extensions - slightly improved diagnostic output of jbgtopbm option -d - non-English translations of error messages are now provided in a separate PO file (e.g., for use with GNU gettext), jbg_strerror() no longer has a language attribute and the JBG_EN, JBG_DE_8859_1, JBG_DE_UTF_8 constants no longer exist - jbg_dec_in() return values changed; the least significant bits of the error codes now provide more information about what caused the error, beyond what the more general error text messages returned by jbg_strerror() reveal - pbmtojbg has a new option -f as a shortcut for all the options needed to make the output comply to the basic ITU-T T.85 fax profile - jbg_dec_getwidth(), jbg_dec_getheight(), jbg_dec_getsize(), and jbg_dec_getsize_merged() return now an unsigned long value (was: long), and return 0 (was: -1) if no image is available yet - jbgtopbm now outputs image dimensions in header padded to 10 digits fixed width, for consistency with jbgtopbm85 to allow for later in-place update of height due to NEWLEN - macro JBG_LICENCE can be changed from the default value "GPL" to a licence agreement reference code to if the library is used under a commercial licence, to clarify under which exact licence the library is used in a particular application Changes in version 1.6 (2004-06-11) - various small changes to reduce the risk of 32-bit unsigned integer overflows when dealing with extremely large images - robuster treatment of L0 = 0xffffffff - minor API modification in jbg_enc_options(): parameter l0 changed from type long to unsigned long; previous value now remains unchanged when l0 == 0 (was: l0 < 0) - lots of type casts added such that the C source code is now also compilable as C++ Changes in version 1.5 (2003-06-11) - fixed two minor memory leaks (special thanks to Davide Pizzolato <ing.davide.pizzolato@libero.it> for locating one of these) - jbgtopbm does not attempt any more to parse multiple concatenated BIEs (options -m must be used now to enable this feature explicitly), in order to handle BIEs with data after the last expected SDE gracefully - various extensions to improve support of JBIG fax applications (ITU-T T.85 profile): o support for maximum adaptive template pixel offset increased to MX=127 in both encoder and decoder o encoder now has a hook for producing BIEs with a NEWLEN marker segment and VLENGTH=1, in order to assist in testing decoders for T.85 conformance (see also new pbmtojbg option -Y) o a new function jbg_newlen() can be used to scan an entire in-memory BIE for NEWLEN marker segments and update the YD value in the BIE header, which can be applied to BIE data before passing it to the decoder for T.85 compliance (Background: the incremental design of the JBIG-KIT decoder makes it infeasible to look ahead for NEWLEN marker segments that occur after the SDE with the last image line, therefore this second pass is necessary to handle the old-style fax applications permitted by T.85 in which the low-RAM encoder doesn't know the height of the image at the start of transmission) Changes in version 1.4 (2002-04-09) - typo fixed in stripe number calculation, which caused encoder and decoder to fail on certain image sizes (special thanks to Koen Denecker <denecker@elis.rug.ac.be> for locating this one) Changes in version 1.3 (2002-03-23): - bugs fixed in jbg_split_planes(), jbg_dec_merge_planes() that caused a failure for more than eight planes per pixel - example converters now can handle PGM files with up to 32 bits per pixel Changes in version 1.2 (2000-04-08): - bug in the decoder fixed, which caused the rest of the input file to be skipped whenever a comment marker was encountered (special thanks to Ben Rudiak-Gould <benrg@math.berkeley.edu> for reporting this one) Changes in version 1.1 (1999-11-16): - serious bug in the encoder fixed, which for a very small percentage of images has caused an unterminated linked list to be created internally that could have been responsible for segmentation violations or non-terminating encoders (special thanks to Hisashi Saiga <saiga@itl.tnr.sharp.co.jp> for tracking that one down) - minor bug in the "jbgtopbm -d" diagnostic output fixed Changes in version 1.0 (1998-04-11): - two bugs fixed that caused the encoder and decoder to fail under certain modes of operation with several bit planes - added new functions jbg_split_planes(), jbg_dec_merge_planes(), and jbg_dec_getsize_merged() for easy handling of grayscale images - added support for compressing grayscale PGM files to pbmtojbg and jbgtopbm - more changes to avoid paranoid compiler warnings Changes in version 0.9 (1996-01-09): - encoder won't break any more on input bitmap data with incorrect zero padding - pbmtojbg displays a warning if input file has incorrect zero padding - various minor improvements suggested by Stefan Willer <Stefan.Willer@unnet.wupper.DE> - many minor changes in order to avoid warnings from paranoid compilers Changes in version 0.8 (1995-09-20): - namespace cleared up, all names externally visible from the library start now with jbg_ or JBG_ - minor non-critical bug fixed which caused library to fail compatibility test and showed up especially on DEC Alpha systems - jbg_dec_gethight() is now called jbg_dec_getheight() - filenames conform now to MS-DOS limits - Bug in pbmtojbg fixed (handling of ASCII PBM files) Changes in version 0.7 (1995-06-10): - more problems on 16-bit int systems and on Macintosh systems fixed (special thanks to Jean-Pierre Gachen <jpg11@calvanet.calvacom.fr>) - global Makefile Changes in version 0.6 (1995-06-08): - memory leak fixed - should now also work on systems where int is only 16-bit large - changes of the JBIG "Technical Corrigendum 1" included (special thanks to Dr. Sebestyen from Siemens AG for sending me a copy of the draft) First release: version 0.5 (1995-05-28) |