CHANGE LOG for Independent JPEG Group's JPEG software 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.