diff -ru libpng-1.2.12/CHANGES libpng/CHANGES
--- libpng-1.2.12/CHANGES	2006-06-27 16:22:34.000000000 -0400
+++ libpng/CHANGES	2006-07-01 12:12:00.000000000 -0400
@@ -1615,10 +1615,7 @@
   Really increased sprintf buffer from 50 to 52 chars in pngrutil.c to avoid
     buffer overflow.
 
-Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-(subscription required; visit
-https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe)
-or to glennrp at users.sourceforge.net
+version 1.2.12-optipng [July 1, 2006]
+  Removed the contrib/ directory (Cosmin).
+  Added pngusr.h (Cosmin).
 
-Glenn R-P
Only in libpng-1.2.12: contrib
diff -ru libpng-1.2.12/png.h libpng/png.h
--- libpng-1.2.12/png.h	2006-06-27 16:22:34.000000000 -0400
+++ libpng/png.h	2006-07-01 12:12:00.000000000 -0400
@@ -1,3 +1,5 @@
+/* MODIFIED version of libpng-1.2.12 by Cosmin Truta */
+#define PNG_USER_CONFIG
 
 /* png.h - header file for PNG reference library
  *
@@ -329,9 +331,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.12"
+#define PNG_LIBPNG_VER_STRING "1.2.12-optipng"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.12 - June 27, 2006 (header)\n"
+   " libpng version 1.2.12-optipng (header)\n"
 
 #define PNG_LIBPNG_VER_SONUM   0
 #define PNG_LIBPNG_VER_DLLNUM  13
Only in libpng: pngusr.h