[devel] Documented png_set_alpha_mode(), other changes in libpng.3 and
libpng-manual.txt.
The cHRM chunk now sets the defaults for png_set_rgb_to_gray() (when negative
parameters are supplied by the caller), while in the absence of cHRM
sRGB/Rec 709 values are still used.
The bKGD chunk no longer overwrites the background value set by
png_set_background(), allowing the latter to be used before the file
header is read. It never performed any useful function to override
the default anyway.
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diff --git a/png.h b/png.h
index d10fd29..9bb53f8 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
/* png.h - header file for PNG reference library
*
- * libpng version 1.5.3beta08 - May 11, 2011
+ * libpng version 1.5.3beta08 - May 13, 2011
* Copyright (c) 1998-2011 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
* Authors and maintainers:
* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- * libpng versions 0.97, January 1998, through 1.5.3beta08 - May 11, 2011: Glenn
+ * libpng versions 0.97, January 1998, through 1.5.3beta08 - May 13, 2011: Glenn
* See also "Contributing Authors", below.
*
* Note about libpng version numbers:
@@ -182,7 +182,7 @@
*
* This code is released under the libpng license.
*
- * libpng versions 1.2.6, August 15, 2004, through 1.5.3beta08, May 11, 2011, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.3beta08, May 13, 2011, are
* Copyright (c) 2004, 2006-2011 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:
@@ -294,7 +294,7 @@
* Y2K compliance in libpng:
* =========================
*
- * May 11, 2011
+ * May 13, 2011
*
* Since the PNG Development group is an ad-hoc body, we can't make
* an official declaration.
@@ -357,7 +357,7 @@
/* Version information for png.h - this should match the version in png.c */
#define PNG_LIBPNG_VER_STRING "1.5.3beta08"
#define PNG_HEADER_VERSION_STRING \
- " libpng version 1.5.3beta08 - May 11, 2011\n"
+ " libpng version 1.5.3beta08 - May 13, 2011\n"
#define PNG_LIBPNG_VER_SONUM 15
#define PNG_LIBPNG_VER_DLLNUM 15
@@ -1400,7 +1400,11 @@
#endif
#ifdef PNG_READ_BACKGROUND_SUPPORTED
-/* Handle alpha and tRNS by replacing with a background color. */
+/* Handle alpha and tRNS by replacing with a background color. Prior to
+ * libpng-1.5.3 this API must not be called before the PNG file header has been
+ * read. Doing so will result in unexpected behavior and possible warnings or
+ * errors int the PNG file contains a bKGD chunk.
+ */
PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
png_const_color_16p background_color, int background_gamma_code,
int need_expand, double background_gamma));
