(2) If only executable code is distributed, then the accompanying documentation must state that "this
software is based in part on the work of the Independent JPEG Group".
(3) Permission for use of this software is granted only if the user accepts full responsibility for any
undesirable consequences; the authors accept NO LIABILITY for damages of any kind.
These conditions apply to any software derived from or based on the IJG code, not just to the unmodified
library. If you use our work, you ought to acknowledge us.
Permission is NOT granted for the use of any IJG author's name or company name in advertising or
publicity relating to this software or products derived from it. This software may be referred to only as
"the Independent JPEG Group's software".
We specifically permit and encourage the use of this software as the basis of commercial products,
provided that all warranty or liability claims are assumed by the product vendor.
ansi2knr.c is included in this distribution by permission of L. Peter Deutsch, sole proprietor of its
copyright holder, Aladdin Enterprises of Menlo Park, CA. ansi2knr.c is NOT covered by the above
copyright and conditions, but instead by the usual distribution terms of the Free Software Foundation;
principally, that you must include source code if you redistribute it. (See the file ansi2knr.c for full details.)
However, since ansi2knr.c is not needed as part of any program generated from the IJG code, this does
not limit you more than the foregoing paragraphs do.
The Unix configuration script "configure" was produced with GNU Autoconf. It is copyright by the Free
Software Foundation but is freely distributable. The same holds for its supporting scripts (config.guess,
config.sub, ltconfig, ltmain.sh). Another support script, install-sh, is copyright by M.I.T. but is also freely
distributable.
It appears that the arithmetic coding option of the JPEG spec is covered by patents owned by IBM,
AT&T, and Mitsubishi. Hence arithmetic coding cannot legally be used without obtaining one or more
licenses. For this reason, support for arithmetic coding has been removed from the free JPEG software.
(Since arithmetic coding provides only a marginal gain over the unpatented Huffman mode, it is unlikely
that very many implementations will support it.) So far as we are aware, there are no patent restrictions
on the remaining code.
The IJG distribution formerly included code to read and write GIF files. To avoid entanglement with the
Unisys LZW patent, GIF reading support has been removed altogether, and the GIF writer has been
simplified to produce "uncompressed GIFs". This technique does not use the LZW algorithm; the
resulting GIF files are larger than usual, but are readable by all standard GIF decoders.
We are required to state that
"The Graphics Interchange Format(c)) is the Copyright property of CompuServe Incorporated. GIF(sm)
is a Service Mark property of CompuServe Incorporated."
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