From tgl@netcom.com Tue Sep 27 18:12:59 1994
Newsgroups: comp.compression,comp.graphics,alt.graphics.pixutils,alt.binaries.pictures.utilities
From: tgl@netcom.com (Tom Lane)
Subject: Free JPEG software version 5 released
Followup-To: comp.compression
Keywords: JPEG, image compression
Reply-To: jpeg-info@uunet.uu.net
Organization: Independent JPEG Group
Date: Mon, 26 Sep 1994 17:49:49 GMT

The Independent JPEG Group is proud to announce the fifth public release
of our free JPEG image compression software.

The C source code, documentation, and test files are available by
anonymous FTP from ftp.uu.net:/graphics/jpeg/jpegsrc.v5.tar.gz.
We will also post it to comp.sources.misc.  The same code will be made
available in a more DOS-friendly format (ie, ZIP) in the SimTel archives
and on CompuServe, but it will take a few days to be submitted there.

The IJG code includes a reusable JPEG compression/decompression library,
plus sample applications "cjpeg" and "djpeg", which perform conversion
between JPEG JFIF format and image files in PPM/PGM (PBMPLUS), GIF, BMP,
Utah RLE, and Targa formats.  Two small applications "wrjpgcom" and
"rdjpgcom" insert and extract textual comments in JFIF files.
The package is highly portable; it has been used successfully on many
machines ranging from Apple IIs to Crays.


Important user-level improvements over version 4 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.

* cjpeg/djpeg support BMP file format.

The application programmer's interface to the library has changed completely.
Notable improvements for the programmer 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.

* 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!


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