- Qt 6.9
- Qt GUI
- LibJPEG-turbo, version 3.1.2
- Qt 6.9.3 Reference Documentation

# LibJPEG-turbo, version 3.1.2

The Independent JPEG Group's JPEG software

Used in the qjpeg image plugin. Configure with -system-libjpeg or -no-libjpeg to avoid.

The sources can be found in qtbase-everywhere-src-6.9.3/src/3rdparty/libjpeg.

Project Homepage, upstream version: 3.1.2

     Copyright (C) 2009-2025 D. R. Commander
     Copyright (C) 2015, 2020 Google, Inc.
     Copyright (C) 2019-2020 Arm Limited
     Copyright (C) 2015-2016, 2018 Matthieu Darbois
     Copyright (C) 2011-2016 Siarhei Siamashka
     Copyright (C) 2015 Intel Corporation
     Copyright (C) 2013-2014 Linaro Limited
     Copyright (C) 2013-2014 MIPS Technologies, Inc.
     Copyright (C) 2009, 2012 Pierre Ossman for Cendio AB
     Copyright (C) 2009-2011 Nokia Corporation and/or its subsidiary(-ies)
     Copyright (C) 1999-2006 MIYASAKA Masaru
     Copyright (C) 1999 Ken Murchison
     Copyright (C) 1991-2020 Thomas G. Lane, Guido Vollbeding

Independent JPEG Group License and BSD 3-Clause "New" or "Revised" License.

     libjpeg-turbo Licenses
     ======================

     libjpeg-turbo is covered by two compatible BSD-style open source licenses:

     - The IJG (Independent JPEG Group) License, which is listed in
       [README.ijg](README.ijg)

       This license applies to the libjpeg API library and associated programs,
       including any code inherited from libjpeg and any modifications to that
       code.  Note that the libjpeg-turbo SIMD source code bears the
       [zlib License](https://opensource.org/licenses/Zlib), but in the context of
       the overall libjpeg API library, the terms of the zlib License are subsumed
       by the terms of the IJG License.

     - The Modified (3-clause) BSD License, which is listed below

       This license applies to the TurboJPEG API library and associated programs, as
       well as the build system.  Note that the TurboJPEG API library wraps the
       libjpeg API library, so in the context of the overall TurboJPEG API library,
       both the terms of the IJG License and the terms of the Modified (3-clause)
       BSD License apply.

     Complying with the libjpeg-turbo Licenses
     =========================================

     This section provides a roll-up of the libjpeg-turbo licensing terms, to the
     best of our understanding.  This is not a license in and of itself.  It is
     intended solely for clarification.

     1.  If you are distributing a modified version of the libjpeg-turbo source,
         then:

         1.  You cannot alter or remove any existing copyright or license notices
             from the source.

             **Origin**
             - Clause 1 of the IJG License
             - Clause 1 of the Modified BSD License
             - Clauses 1 and 3 of the zlib License

         2.  You must add your own copyright notice to the header of each source
             file you modified, so others can tell that you modified that file.  (If
             there is not an existing copyright header in that file, then you can
             simply add a notice stating that you modified the file.)

             **Origin**
             - Clause 1 of the IJG License
             - Clause 2 of the zlib License

         3.  You must include the IJG README file, and you must not alter any of the
             copyright or license text in that file.

             **Origin**
             - Clause 1 of the IJG License

     2.  If you are distributing only libjpeg-turbo binaries without the source, or
         if you are distributing an application that statically links with
         libjpeg-turbo, then:

         1.  Your product documentation must include a message stating:

             This software is based in part on the work of the Independent JPEG
             Group.

             **Origin**
             - Clause 2 of the IJG license

         2.  If your binary distribution includes or uses the TurboJPEG API, then
             your product documentation must include the text of the Modified BSD
             License (see below.)

             **Origin**
             - Clause 2 of the Modified BSD License

     3.  You cannot use the name of the IJG or The libjpeg-turbo Project or the
         contributors thereof in advertising, publicity, etc.

         **Origin**
         - IJG License
         - Clause 3 of the Modified BSD License

     4.  The IJG and The libjpeg-turbo Project do not warrant libjpeg-turbo to be
         free of defects, nor do we accept any liability for undesirable
         consequences resulting from your use of the software.

         **Origin**
         - IJG License
         - Modified BSD License
         - zlib License

     The Modified (3-clause) BSD License
     ===================================

     Copyright (C)2009-2025 D. R. Commander.  All Rights Reserved.<br>
     Copyright (C)2015 Viktor Szathmáry.  All Rights Reserved.

     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions are met:

     - Redistributions of source code must retain the above copyright notice,
       this list of conditions and the following disclaimer.
     - Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.
     - Neither the name of the libjpeg-turbo Project nor the names of its
       contributors may be used to endorse or promote products derived from this
       software without specific prior written permission.

     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
     LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     POSSIBILITY OF SUCH DAMAGE.

     Why Two Licenses?
     =================

     The zlib License could have been used instead of the Modified (3-clause) BSD
     License, and since the IJG License effectively subsumes the distribution
     conditions of the zlib License, this would have effectively placed
     libjpeg-turbo binary distributions under the IJG License.  However, the IJG
     License specifically refers to the Independent JPEG Group and does not extend
     attribution and endorsement protections to other entities.  Thus, it was
     desirable to choose a license that granted us the same protections for new code
     that were granted to the IJG for code derived from their software.

     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) 1991-2020, 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.