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- From: tgl+@cs.cmu.edu (Tom Lane)
- Newsgroups: comp.archives
- Subject: [comp.compression] Version 4 of free JPEG software released
- Followup-To: comp.compression
- Date: 14 Dec 1992 08:17:01 GMT
- Organization: School of Computer Science, Carnegie Mellon
- Lines: 58
- Sender: adam@soda
- Approved: adam@soda
- Distribution: world
- Message-ID: <1ghfttINNla7@agate.berkeley.edu>
- References: <Bz80DH.G5t.2@cs.cmu.edu>
- Reply-To: jpeg-info@uunet.uu.net
- NNTP-Posting-Host: soda.berkeley.edu
- X-Original-Newsgroups: comp.compression,comp.compression.research,comp.graphics,alt.graphics.pixutils,alt.binaries.pictures.utilities
- X-Original-Date: Sun, 13 Dec 1992 23:10:22 GMT
-
- Archive-name: auto/comp.compression/Version-4-of-free-JPEG-software-released
-
- The Independent JPEG Group is proud to announce the fourth public release
- of our free JPEG image compression software.
-
- The C source code, documentation, and test files are available for anonymous
- FTP from FTP.UU.NET (137.39.1.9), file graphics/jpeg/jpegsrc.v4.tar.Z.
- The package will shortly be available on CompuServe, in the GRAPHSUPPORT
- forum (GO PICS), library 15, as jpsrc4.zip. We intend to post the source
- code in comp.sources.misc and executables in appropriate binaries groups.
-
-
- The distributed code provides conversion between JPEG "JFIF" format and
- image files in PBMPLUS PPM/PGM, Utah RLE, Truevision Targa, and GIF file
- formats. The core compression and decompression modules can easily be
- reused in other programs, such as image viewers. The package is highly
- portable C code; we have tested it on many machines ranging from PCs to
- Crays.
-
- Important improvements over version 3 include:
-
- * Significant speedups. The basic JPEG compression and decompression
- operations are typically about a factor of 2 faster than v3. (Your
- mileage will vary depending on CPU type and C compiler.)
-
- * Improved image quality, due to more accurate DCT and resampling
- algorithms.
-
- * Error recovery capability has been added to the decompressor, so that
- it can cope with damaged JPEG files. While damage to the compressed
- data will scramble the output image, the effects of damage can be
- confined to small areas of the image if the file was originally created
- with "restart" markers. Even severe damage will only result in loss of
- the damaged restart segments; the rest of the image can still be recovered.
-
- * Redesigned command line switches provide access to more JPEG parameter
- settings, including restart marker generation in the compressor.
-
- * There is an option for smoothing the input image before JPEG compression.
- This helps a lot when converting dithered GIFs to JPEG.
-
- * Portability is even better than v3.
-
-
- We are releasing this software for both noncommercial and commercial use.
- Companies are welcome to use it as the basis for JPEG-related products.
- We do not ask a royalty, although we do ask for an acknowledgement in
- product literature (see the README file in the distribution for details).
- We hope to make this software industrial-quality --- although, as with
- anything that's free, we offer no warranty and accept no liability.
-
- Please direct any questions about this software to jpeg-info@uunet.uu.net.
-
- --
- Dr. Thomas G. Lane
- organizer, Independent JPEG Group
- Internet: tgl@cs.cmu.edu BITNET: tgl%cs.cmu.edu@cmuccvma
-
-