This copy of the libpng notices is provided for your convenience.  In case of
                any discrepancy between this copy and the notices in the file png.h that is
                included in the libpng distribution, the latter shall prevail.
    
                COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
    
                If you modify libpng you may insert additional notices immediately following
                this sentence.
    
                This code is released under the libpng license.
    
                libpng versions 1.0.7, July 1, 2000 through 1.6.31, July 27, 2017 are
                Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
                derived from libpng-1.0.6, and are distributed according to the same
                disclaimer and license as libpng-1.0.6 with the following individuals
                added to the list of Contributing Authors:
                
                   Simon-Pierre Cadieux
                   Eric S. Raymond
                   Mans Rullgard
                   Cosmin Truta
                   Gilles Vollant
                   James Yu
                   Mandar Sahastrabuddhe
                   Google Inc.
                   Vadim Barkov
    
                and with the following additions to the disclaimer:
    
                There is no warranty against interference with your enjoyment of the
                library or against infringement.  There is no warranty that our
                efforts or the library will fulfill any of your particular purposes
                or needs.  This library is provided with all faults, and the entire
                risk of satisfactory quality, performance, accuracy, and effort is with
                the user.
    
                Some files in the "contrib" directory and some configure-generated
                files that are distributed with libpng have other copyright owners and
                are released under other open source licenses.
    
                libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
                Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
                libpng-0.96, and are distributed according to the same disclaimer and
                license as libpng-0.96, with the following individuals added to the list
                of Contributing Authors:
    
                   Tom Lane
                   Glenn Randers-Pehrson
                   Willem van Schaik
                
                libpng versions 0.89, June 1996, through 0.96, May 1997, are
                Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
                and are distributed according to the same disclaimer and license as
                libpng-0.88, with the following individuals added to the list of
                Contributing Authors:
    
                   John Bowler
                   Kevin Bracey
                   Sam Bushell
                   Magnus Holmgren
                   Greg Roelofs
                Tom Tanner
                
                Some files in the "scripts" directory have other copyright owners
                but are released under this license.
    
                libpng versions 0.5, May 1995, through 0.88, January 1996, are
                Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
    
                For the purposes of this copyright and license, "Contributing Authors"
                is defined as the following set of individuals:
                
                   Andreas Dilger
                   Dave Martindale
                   Guy Eric Schalnat
                   Paul Schmidt
                   Tim Wegner
    
                The PNG Reference Library is supplied "AS IS".  The Contributing Authors
                and Group 42, Inc. disclaim all warranties, expressed or implied,
                including, without limitation, the warranties of merchantability and of
                fitness for any purpose.  The Contributing Authors and Group 42, Inc.
                assume no liability for direct, indirect, incidental, special, exemplary,
                or consequential damages, which may result from the use of the PNG
                Reference Library, even if advised of the possibility of such damage.
    
                Permission is hereby granted to use, copy, modify, and distribute this
                source code, or portions hereof, for any purpose, without fee, subject
                to the following restrictions:
    
                  1. The origin of this source code must not be misrepresented.
    
                  2. Altered versions must be plainly marked as such and must not
                     be misrepresented as being the original source.
    
                  3. This Copyright notice may not be removed or altered from any
                     source or altered source distribution.
    
                The Contributing Authors and Group 42, Inc. specifically permit, without
                fee, and encourage the use of this source code as a component to
                supporting the PNG file format in commercial products.  If you use this
                source code in a product, acknowledgment is not required but would be
                appreciated.