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■ About Expat
Copyright (C) 1998, 1999, 2000 Thai Open Source Software Center Ltd
and Clark Cooper
Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Expat maintainers.
Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and associated documentation files (the “Software”), to deal in the Software
without restriction, including without limitation the rights to use, copy, modify, merge,
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to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
■ About cURL
COPYRIGHT AND PERMISSION NOTICE
Copyright (C) 1996 - 2009, Daniel Stenberg, <daniel@haxx.se>.
All rights reserved.
Permission to use, copy, modify, and distribute this software for any purpose with or
without fee is hereby granted, provided that the above copyright notice and this
permission notice appear in all copies.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY
KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
Except as contained in this notice, the name of a copyright holder shall not be used in
advertising or otherwise to promote the sale, use or other dealings in this Software
without prior written authorization of the copyright holder.
■ About Independent JPEG group
The Independent JPEG Group’s JPEG software
README for release 7 of 27-Jun-2009
This distribution contains the seventh public release of the Independent JPEG Group’s
free JPEG software. You are welcome to redistribute this software and to use it for any
purpose, subject to the conditions under LEGAL ISSUES, below.
This software is the work of Tom Lane, Guido Vollbeding, Philip Gladstone, Bill
Allombert, Jim Boucher, Lee Crocker, Bob Friesenhahn, Ben Jackson, Julian
Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Ge’ Weijers, and other members
of the Independent JPEG Group.
IJG is not affiliated with the official ISO JPEG standards committee.
DOCUMENTATION ROADMAP
This file contains the following sections:
OVERVIEW General description of JPEG and the IJG software.
LEGAL ISSUES Copyright, lack of warranty, terms of distribution.
REFERENCES Where to learn more about JPEG.
ARCHIVE LOCATIONS Where to find newer versions of this software.
ACKNOWLEDGMENTS Special thanks.
FILE FORMAT WARS Software *not* to get.
TO DO Plans for future IJG releases.
Other documentation files in the distribution are:
User documentation:
install.txt How to configure and install the IJG software.
usage.txt Usage instructions for cjpeg, djpeg, jpegtran, rdjpgcom, and
wrjpgcom.
*.1 Unix-style man pages for programs (same info as usage.txt).
wizard.txt Advanced usage instructions for JPEG wizards only.
change.log Version-to-version change highlights.
Programmer and internal documentation:
libjpeg.txt How to use the JPEG library in your own programs.
example.c Sample code for calling the JPEG library.
structure.txt Overview of the JPEG library’s internal structure.
filelist.txt Road map of IJG files.
coderules.txt Coding style rules --- please read if you contribute code.
Please read at least the files install.txt and usage.txt. Some information can also be
found in the JPEG FAQ (Frequently Asked Questions) article. See ARCHIVE
LOCATIONS below to find out where to obtain the FAQ article.
If you want to understand how the JPEG code works, we suggest reading one or more
of the REFERENCES, then looking at the documentation files (in roughly the order
listed) before diving into the code.
OVERVIEW
This package contains C software to implement JPEG image encoding, decoding, and
transcoding. JPEG (pronounced “jay-peg”) is a standardized compression method for
full-color and gray-scale images.
This software implements JPEG baseline, extended-sequential, and progressive
compression processes. Provision is made for supporting all variants of these processes,
although some uncommon parameter settings aren’t implemented yet. We have made
no provision for supporting the hierarchical or lossless processes defined in the
standard.
We provide a set of library routines for reading and writing JPEG image files, plus two
sample applications “cjpeg” and “djpeg”, which use the library to perform conversion
between JPEG and some other popular image file formats. The library is intended to be
reused in other applications.
In order to support file conversion and viewing software, we have included
considerable functionality beyond the bare JPEG coding/decoding capability; for
example, the color quantization modules are not strictly part of JPEG decoding, but
they are essential for output to colormapped file formats or colormapped displays.
These extra functions can be compiled out of the library if not required for a particular
application.
We have also included “jpegtran”, a utility for lossless transcoding between different
JPEG processes, and “rdjpgcom” and “wrjpgcom”, two simple applications for
inserting and extracting textual comments in JFIF files.
The emphasis in designing this software has been on achieving portability and
flexibility, while also making it fast enough to be useful. In particular, the software is
not intended to be read as a tutorial on JPEG. (See the REFERENCES section for
introductory material.) Rather, it is intended to be reliable, portable, industrial-strength
code. We do not claim to have achieved that goal in every aspect of the software, but
we strive for it.
We welcome the use of this software as a component of commercial products. No
royalty is required, but we do ask for an acknowledgement in product documentation,
as described under LEGAL ISSUES.
LEGAL ISSUES
In plain English:
1. We don’t promise that this software works. (But if you find any bugs, please let us
know!)
2. You can use this software for whatever you want. You don’t have to pay us.
3. You may not pretend that you wrote this software. If you use it in a program, you
must acknowledge somewhere in your documentation that you’ve used the IJG code.
In legalese:
The authors make NO WARRANTY or representation, either express or implied, with
respect to this software, its quality, accuracy, merchantability, or fitness for a particular
purpose. This software is provided “AS IS”, and you, its user, assume the entire risk as
to its quality and accuracy.
This software is copyright (C) 1991-2009, Thomas G. Lane, Guido Vollbeding.
All Rights Reserved except as specified below.
Permission is hereby granted to use, copy, modify, and distribute this software (or
portions thereof) for any purpose, without fee, subject to these conditions:
(1) If any part of the source code for this software is distributed, then this README file
must be included, with this copyright and no-warranty notice unaltered; and any
additions, deletions, or changes to the original files must be clearly indicated in
accompanying documentation.
(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, ltmain.sh). Another support script,
install-sh, is copyright by X Consortium but is also freely distributable.
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.”
REFERENCES
We recommend reading one or more of these references before trying to understand the
innards of the JPEG software.
The best short technical introduction to the JPEG compression algorithm is
Wallace, Gregory K. “The JPEG Still Picture Compression Standard”,
