1## Independent JPEG Group: JPEG release 6b
2
3### JPEG License
4
5```
6****************************************************************************
7
8Copyright (C) 1991-1998, Thomas G. Lane.
9
10This software is the work of Tom Lane, Philip Gladstone, Jim Boucher,
11Lee Crocker, Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi,
12Guido Vollbeding, Ge' Weijers, and other members of the Independent JPEG
13Group.
14
15IJG is not affiliated with the official ISO JPEG standards committee.
16
17The authors make NO WARRANTY or representation, either express or implied,
18with respect to this software, its quality, accuracy, merchantability, or
19fitness for a particular purpose.  This software is provided "AS IS",
20and you, its user, assume the entire risk as to its quality and accuracy.
21
22This software is copyright (C) 1991-1998, Thomas G. Lane.
23All Rights Reserved except as specified below.
24
25Permission is hereby granted to use, copy, modify, and distribute
26this software (or portions thereof) for any purpose, without fee,
27subject to these conditions:
28
29(1) If any part of the source code for this software is distributed,
30then this README file must be included, with this copyright and no-warranty
31notice unaltered; and any additions, deletions, or changes to the original
32files must be clearly indicated in accompanying documentation.
33
34(2) If only executable code is distributed, then the accompanying documentation
35must state that "this software is based in part on the work of the
36Independent JPEG Group".
37
38(3) Permission for use of this software is granted only if the user accepts
39full responsibility for any undesirable consequences; the authors accept
40NO LIABILITY for damages of any kind.
41
42These conditions apply to any software derived from or based on the IJG code,
43not just to the unmodified library.  If you use our work, you ought to
44acknowledge us.
45
46Permission is NOT granted for the use of any IJG author's name or company name
47in advertising or publicity relating to this software or products derived
48from it.  This software may be referred to only as "the Independent JPEG
49Group's software".
50
51We specifically permit and encourage the use of this software as the basis
52of commercial products, provided that all warranty or liability claims are
53assumed by the product vendor.
54
55It appears that the arithmetic coding option of the JPEG spec is covered
56by patents owned by IBM, AT&T, and Mitsubishi.  Hence arithmetic coding
57cannot legally be used without obtaining one or more licenses.  For this
58reason, support for arithmetic coding has been removed from the free
59JPEG software. (Since arithmetic coding provides only a marginal gain
60over the unpatented Huffman mode, it is unlikely that very many
61implementations will support it.) So far as we are aware, there are
62no patent restrictions on the remaining code.
63
64The IJG distribution formerly included code to read and write GIF files.
65To avoid entanglement with the Unisys LZW patent, GIF reading support
66has been removed altogether, and the GIF writer has been simplified to
67produce "uncompressed GIFs".  This technique does not use the LZW algorithm;
68the resulting GIF files are larger than usual, but are readable by all
69standard GIF decoders.
70
71We are required to state that "The Graphics Interchange Format(c) is
72the Copyright property of CompuServe Incorporated.  GIF(sm) is a
73Service Mark property of CompuServe Incorporated."
74
75****************************************************************************
76```
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