If you modify libpng you may insert additional notices immediately following
this sentence.
-libpng versions 1.2.6, August 15, 2004, through 1.2.34, December 18, 2008, are
-Copyright (c) 2004, 2006-2008 Glenn Randers-Pehrson, and are
+This code is released under the libpng license.
+
+libpng versions 1.2.6, August 15, 2004, through 1.6.2, April 25, 2013, are
+Copyright (c) 2004, 2006-2012 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-1.2.5
with the following individual added to the list of Contributing Authors
Glenn Randers-Pehrson
glennrp at users.sourceforge.net
-December 18, 2008
+April 25, 2013