libjpeg-turbo Licenses

======================

libjpeg-turbo is covered by three 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

  (any code inherited from libjpeg, and any modifications to that code.)

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

  This license covers the TurboJPEG API library and associated programs, as

  well as the build system.

- The [zlib License](https://opensource.org/licenses/Zlib)

  This license is a subset of the other two, and it covers the libjpeg-turbo

  SIMD extensions.

Complying with the libjpeg-turbo Licenses

=========================================

This section provides a roll-up of the libjpeg-turbo licensing terms, to the

best of our understanding.

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)2009-2020 D. R. Commander.  All Rights Reserved.

Copyright (C)2015 Viktor Szathmรกry.  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 Three 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.