Copyright (c) 2004-2007 Stuart Coyle  

Copyright (c) 1998-2002 Greg Roelofs.  All rights reserved.

This software is provided "as is," without warranty of any kind,
express or implied.  In no event shall the author or contributors
be held liable for any damages arising in any way from the use of
this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute
it freely, subject to the following restrictions:

1. Redistributions of source code must retain the above copyright
   notice, disclaimer, and this list of conditions.
2. Redistributions in binary form must reproduce the above copyright
   notice, disclaimer, and this list of conditions in the documenta-
   tion and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this
   software must display the following acknowledgment:

      This product includes software developed by Greg Roelofs
      and contributors for the book, "PNG: The Definitive Guide,"
      published by O'Reilly and Associates.

Thank you!