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[master] Ported bugfix in pngrtran.c from 1.5.3: Ensure coefficients are OK for

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png_rgb_to_gray_fixed().
This commit is contained in:
Glenn Randers-Pehrson 2011-06-05 17:19:17 -05:00
parent c3ac9a507a
commit 0dc882d7c3
3 changed files with 41 additions and 26 deletions
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22
ANNOUNCE
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@ -1,5 +1,5 @@
Libpng 1.4.8rc01 - June 4, 2011 Libpng 1.4.8beta02 - June 5, 2011
This is not intended to be a public release. It will be replaced This is not intended to be a public release. It will be replaced
within a few weeks by a public version or by another test version. within a few weeks by a public version or by another test version.
@ -9,20 +9,20 @@ Files available for download:
Source files with LF line endings (for Unix/Linux) and with a Source files with LF line endings (for Unix/Linux) and with a
"configure" script "configure" script
1.4.8rc01.tar.xz (LZMA-compressed, recommended) 1.4.8beta02.tar.xz (LZMA-compressed, recommended)
1.4.8rc01.tar.gz 1.4.8beta02.tar.gz
1.4.8rc01.tar.bz2 1.4.8beta02.tar.bz2
Source files with CRLF line endings (for Windows), without the Source files with CRLF line endings (for Windows), without the
"configure" script "configure" script
lp148r01.7z (LZMA-compressed, recommended) lp148b02.7z (LZMA-compressed, recommended)
lp148r01.zip lp148b02.zip
Other information: Other information:
1.4.8rc01-README.txt 1.4.8beta02-README.txt
1.4.8rc01-LICENSE.txt 1.4.8beta02-LICENSE.txt
Changes since the last public release (1.4.7): Changes since the last public release (1.4.7):
@ -34,10 +34,12 @@ version 1.4.8beta01 [June 4, 2011]
was introduced in libpng-1.2.20beta01. was introduced in libpng-1.2.20beta01.
Check for up->location !PNG_AFTER_IDAT when writing unknown chunks Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
before IDAT. before IDAT.
Port change to pngrtran.c from 1.5.3: when expanding a paletted image, Ported bugfix in pngrtran.c from 1.5.3: when expanding a paletted image,
always expand to RGBA if transparency is present. always expand to RGBA if transparency is present.
version 1.4.8beta02 [June 4, 2011] version 1.4.8beta02 [June 5, 2011]
Ported bugfix in pngrtran.c from 1.5.3: Ensure coefficients are OK for
png_rgb_to_gray_fixed().
Send comments/corrections/commendations to glennrp at users.sourceforge.net Send comments/corrections/commendations to glennrp at users.sourceforge.net
or to png-mng-implement at lists.sf.net (subscription required; visit or to png-mng-implement at lists.sf.net (subscription required; visit

6
CHANGES
View File

@ -2802,10 +2802,12 @@ version 1.4.8beta01 [June 4, 2011]
was introduced in libpng-1.2.20beta01. was introduced in libpng-1.2.20beta01.
Check for up->location !PNG_AFTER_IDAT when writing unknown chunks Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
before IDAT. before IDAT.
Port change to pngrtran.c from 1.5.3: when expanding a paletted image, Ported bugfix in pngrtran.c from 1.5.3: when expanding a paletted image,
always expand to RGBA if transparency is present. always expand to RGBA if transparency is present.
version 1.4.8beta02 [June 4, 2011] version 1.4.8beta02 [June 5, 2011]
Ported bugfix in pngrtran.c from 1.5.3: Ensure coefficients are OK for
png_rgb_to_gray_fixed().
Send comments/corrections/commendations to glennrp at users.sourceforge.net Send comments/corrections/commendations to glennrp at users.sourceforge.net
or to png-mng-implement at lists.sf.net (subscription required; visit or to png-mng-implement at lists.sf.net (subscription required; visit

39
pngrtran.c
View File

@ -703,27 +703,38 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
} }
#endif #endif
{ {
png_uint_16 red_int, green_int; if (red >= 0 && green >= 0 && red + green <= 100000L)
if (red < 0 || green < 0)
{
red_int = 6968; /* .212671 * 32768 + .5 */
green_int = 23434; /* .715160 * 32768 + .5 */
}
else if (red + green < 100000L)
{ {
png_uint_16 red_int, green_int;
red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
png_ptr->rgb_to_gray_red_coeff = red_int;
png_ptr->rgb_to_gray_green_coeff = green_int;
png_ptr->rgb_to_gray_blue_coeff =
(png_uint_16)(32768 - red_int - green_int);
} }
else else
{ {
png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); if (red >= 0 && green >= 0)
red_int = 6968; png_warning(png_ptr,
green_int = 23434; "ignoring out of range rgb_to_gray coefficients");
/* Use the defaults, from the cHRM chunk if set, else the built in Rec
* 709 values (which correspond to sRGB, so we don't have to worry
* about the sRGB chunk!)
*/
if (png_ptr->rgb_to_gray_red_coeff == 0 &&
png_ptr->rgb_to_gray_green_coeff == 0 &&
png_ptr->rgb_to_gray_blue_coeff == 0)
{
png_ptr->rgb_to_gray_red_coeff = 6968; /* .212671 * 32768 + .5 */
png_ptr->rgb_to_gray_green_coeff = 23434; /* .715160 * 32768 + .5 */
png_ptr->rgb_to_gray_blue_coeff = 2366;
}
} }
png_ptr->rgb_to_gray_red_coeff = red_int;
png_ptr->rgb_to_gray_green_coeff = green_int;
png_ptr->rgb_to_gray_blue_coeff =
(png_uint_16)(32768 - red_int - green_int);
} }
} }
#endif #endif