| CHANGE LOG for Independent JPEG Group's JPEG software |
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| Version 5b 15-Mar-95 |
| --------------------- |
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| Correct bugs with grayscale images having v_samp_factor > 1. |
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| jpeg_write_raw_data() now supports output suspension. |
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| Correct bugs in "configure" script for case of compiling in |
| a directory other than the one containing the source files. |
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| Repair bug in jquant1.c: sometimes didn't use as many colors as it could. |
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| Borland C makefile and jconfig file work under either MS-DOS or OS/2. |
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| Miscellaneous improvements to documentation. |
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| Version 5a 7-Dec-94 |
| -------------------- |
| |
| Changed color conversion roundoff behavior so that grayscale values are |
| represented exactly. (This causes test image files to change.) |
| |
| Make ordered dither use 16x16 instead of 4x4 pattern for a small quality |
| improvement. |
| |
| New configure script based on latest GNU Autoconf. |
| Fix configure script to handle CFLAGS correctly. |
| Rename *.auto files to *.cfg, so that configure script still works if |
| file names have been truncated for DOS. |
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| Fix bug in rdbmp.c: didn't allow for extra data between header and image. |
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| Modify rdppm.c/wrppm.c to handle 2-byte raw PPM/PGM formats for 12-bit data. |
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| Fix several bugs in rdrle.c. |
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| NEED_SHORT_EXTERNAL_NAMES option was broken. |
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| Revise jerror.h/jerror.c for more flexibility in message table. |
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| Repair oversight in jmemname.c NO_MKTEMP case: file could be there |
| but unreadable. |
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| Version 5 24-Sep-94 |
| -------------------- |
| |
| Version 5 represents a nearly complete redesign and rewrite of the IJG |
| software. Major user-visible changes include: |
| * Automatic configuration simplifies installation for most Unix systems. |
| * A range of speed vs. image quality tradeoffs are supported. |
| This includes resizing of an image during decompression: scaling down |
| by a factor of 1/2, 1/4, or 1/8 is handled very efficiently. |
| * New programs rdjpgcom and wrjpgcom allow insertion and extraction |
| of text comments in a JPEG file. |
| |
| The application programmer's interface to the library has changed completely. |
| Notable improvements include: |
| * We have eliminated the use of callback routines for handling the |
| uncompressed image data. The application now sees the library as a |
| set of routines that it calls to read or write image data on a |
| scanline-by-scanline basis. |
| * The application image data is represented in a conventional interleaved- |
| pixel format, rather than as a separate array for each color channel. |
| This can save a copying step in many programs. |
| * The handling of compressed data has been cleaned up: the application can |
| supply routines to source or sink the compressed data. It is possible to |
| suspend processing on source/sink buffer overrun, although this is not |
| supported in all operating modes. |
| * All static state has been eliminated from the library, so that multiple |
| instances of compression or decompression can be active concurrently. |
| * JPEG abbreviated datastream formats are supported, ie, quantization and |
| Huffman tables can be stored separately from the image data. |
| * And not only that, but the documentation of the library has improved |
| considerably! |
| |
| |
| The last widely used release before the version 5 rewrite was version 4A of |
| 18-Feb-93. Change logs before that point have been discarded, since they |
| are not of much interest after the rewrite. |
