mirror of
https://git.code.sf.net/p/libpng/code.git
synced 2025-07-10 18:04:09 +02:00
[alpha] Added "double gamma" to parameters for png_set_premultiply_alpha().
Added "float gamma_premultiply" member to the png_struct.
Moved PNG_DIVIDE_BY_255, PNG_8_BIT_PREMULTIPLY(), etc., from
png.h to pngpriv.h
Updated documentation about png_set_premultiply_alpha().
This commit is contained in:
Glenn Randers-Pehrson
26
ANNOUNCE
26
ANNOUNCE
@@ -1,5 +1,5 @@
|
||||
|
||||
Libpng 1.4.1alpha01 - November 27, 2009
|
||||
Libpng 1.4.1alpha02 - November 28, 2009
|
||||
|
||||
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.
|
||||
@@ -9,25 +9,33 @@ Files available for download:
|
||||
Source files with LF line endings (for Unix/Linux) and with a
|
||||
"configure" script
|
||||
|
||||
1.4.1alpha01.tar.xz (LZMA-compressed, recommended)
|
||||
1.4.1alpha01.tar.gz
|
||||
1.4.1alpha01.tar.bz2
|
||||
1.4.1alpha02.tar.xz (LZMA-compressed, recommended)
|
||||
1.4.1alpha02.tar.gz
|
||||
1.4.1alpha02.tar.bz2
|
||||
|
||||
Source files with CRLF line endings (for Windows), without the
|
||||
"configure" script
|
||||
|
||||
lp141a01.zip
|
||||
lp141a01.7z
|
||||
lp141a02.zip
|
||||
lp141a02.7z
|
||||
|
||||
Other information:
|
||||
|
||||
1.4.1alpha01-README.txt
|
||||
1.4.1alpha01-LICENSE.txt
|
||||
1.4.1alpha02-README.txt
|
||||
1.4.1alpha02-LICENSE.txt
|
||||
|
||||
Changes since the last public release (1.4.0beta107):
|
||||
|
||||
version 1.4.1alpha01 [November 27, 2009]
|
||||
Based on version 1.4.0beta107
|
||||
Based on 1.4.0beta107
|
||||
|
||||
version 1.4.1alpha02 [November 28, 2009]
|
||||
Restored premultiplied alpha feature from version 1.4.0beta105.
|
||||
Added "double gamma" to parameters for png_set_premultiply_alpha().
|
||||
Added "float gamma_premultiply" member to the png_struct.
|
||||
Moved PNG_DIVIDE_BY_255, PNG_8_BIT_PREMULTIPLY(), etc., from
|
||||
png.h to pngpriv.h
|
||||
Updated documentation about png_set_premultiply_alpha().
|
||||
|
||||
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
|
||||
(subscription required; visit
|
||||
|
||||
14
CHANGES
14
CHANGES
@@ -2396,8 +2396,9 @@ version 1.4.0beta104 [November 22, 2009]
|
||||
Rebuilt configure scripts with autoconf-2.65
|
||||
|
||||
version 1.4.0beta105 [November 25, 2009]
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||||
Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535() to accomplish
|
||||
alpha premultiplication when PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
|
||||
Use fast integer PNG_DIVIDE_BY_255() or PNG_DIVIDE_BY_65535() to
|
||||
accomplish alpha premultiplication when
|
||||
PNG_READ_COMPOSITE_NODIV_SUPPORTED is defined.
|
||||
Changed "/255" to "/255.0" in background calculations to make it clear
|
||||
that the 255 is used as a double.
|
||||
|
||||
@@ -2408,6 +2409,15 @@ version 1.4.0beta107 [November 27, 2009]
|
||||
Updated README
|
||||
|
||||
version 1.4.1alpha01 [November 27, 2009]
|
||||
Based on 1.4.0beta107
|
||||
|
||||
version 1.4.1alpha02 [November 28, 2009]
|
||||
Restored premultiplied alpha feature from version 1.4.0beta105.
|
||||
Added "double gamma" to parameters for png_set_premultiply_alpha().
|
||||
Added "float gamma_premultiply" member to the png_struct.
|
||||
Moved PNG_DIVIDE_BY_255, PNG_8_BIT_PREMULTIPLY(), etc., from
|
||||
png.h to pngpriv.h
|
||||
Updated documentation about png_set_premultiply_alpha().
|
||||
|
||||
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
|
||||
(subscription required; visit
|
||||
|
||||
@@ -1,6 +1,6 @@
|
||||
libpng.txt - A description on how to use and modify libpng
|
||||
|
||||
libpng version 1.4.1alpha02 - November 27, 2009
|
||||
libpng version 1.4.1alpha02 - November 28, 2009
|
||||
Updated and distributed by Glenn Randers-Pehrson
|
||||
<glennrp at users.sourceforge.net>
|
||||
Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
@@ -11,7 +11,7 @@ libpng.txt - A description on how to use and modify libpng
|
||||
|
||||
Based on:
|
||||
|
||||
libpng versions 0.97, January 1998, through 1.4.1alpha02 - November 27, 2009
|
||||
libpng versions 0.97, January 1998, through 1.4.1alpha02 - November 28, 2009
|
||||
Updated and distributed by Glenn Randers-Pehrson
|
||||
Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
|
||||
@@ -938,6 +938,21 @@ images) is fully transparent, with
|
||||
|
||||
png_set_invert_alpha(png_ptr);
|
||||
|
||||
The PNG format only supports pixels with postmultiplied alpha.
|
||||
If you want to replace the pixels, after reading them, with pixels
|
||||
that have premultiplied color samples, you can do this with
|
||||
|
||||
png_set_premultiply_alpha(png_ptr, output_gamma);
|
||||
|
||||
where gamma is a double containing the gamma associated with the
|
||||
premultiplied pixels. The gamma of the input must also be available
|
||||
when the premultiplication takes place, via a gAMA chunk in the
|
||||
input file or via png_set_gAMA(). If neither is present, the
|
||||
premultiplication will assume input_gamma==(1/2.2)
|
||||
|
||||
If you do this, any input with a tRNS chunk will be expanded to
|
||||
have an alpha channel.
|
||||
|
||||
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
|
||||
they can, resulting in, for example, 8 pixels per byte for 1 bit
|
||||
files. This code expands to 1 pixel per byte without changing the
|
||||
@@ -3026,6 +3041,9 @@ after the png_malloc() to set the pointers to NULL.
|
||||
We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
|
||||
input transforms.
|
||||
|
||||
We added the png_set_premultiply_alpha and
|
||||
png_do_read_premultiply_alpha() functions.
|
||||
|
||||
The call to png_do_chop() in pngrtran.c, which reduces 16-bit input
|
||||
files to 8-bit bit depth, was relocated ahead of the building
|
||||
of gamma tables. This allows us to build 8-bit tables instead
|
||||
@@ -3213,7 +3231,7 @@ Other rules can be inferred by inspecting the libpng source.
|
||||
|
||||
XIII. Y2K Compliance in libpng
|
||||
|
||||
November 27, 2009
|
||||
November 28, 2009
|
||||
|
||||
Since the PNG Development group is an ad-hoc body, we can't make
|
||||
an official declaration.
|
||||
|
||||
44
libpng.3
44
libpng.3
@@ -1,6 +1,6 @@
|
||||
.TH LIBPNG 3 "November 27, 2009"
|
||||
.TH LIBPNG 3 "November 28, 2009"
|
||||
.SH NAME
|
||||
libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha01
|
||||
libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha02
|
||||
.SH SYNOPSIS
|
||||
\fI\fB
|
||||
|
||||
@@ -566,6 +566,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha01
|
||||
|
||||
\fI\fB
|
||||
|
||||
\fBvoid png_set_premultiply_alpha (png_structp \fP\fIpng_ptr\fP\fB, double \fIgamma\fP\fB);\fP
|
||||
|
||||
\fI\fB
|
||||
|
||||
\fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP
|
||||
|
||||
\fI\fB
|
||||
@@ -777,7 +781,7 @@ Following is a copy of the libpng.txt file that accompanies libpng.
|
||||
.SH LIBPNG.TXT
|
||||
libpng.txt - A description on how to use and modify libpng
|
||||
|
||||
libpng version 1.4.1alpha01 - November 27, 2009
|
||||
libpng version 1.4.1alpha02 - November 28, 2009
|
||||
Updated and distributed by Glenn Randers-Pehrson
|
||||
<glennrp at users.sourceforge.net>
|
||||
Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
@@ -788,7 +792,7 @@ libpng.txt - A description on how to use and modify libpng
|
||||
|
||||
Based on:
|
||||
|
||||
libpng versions 0.97, January 1998, through 1.4.1alpha01 - November 27, 2009
|
||||
libpng versions 0.97, January 1998, through 1.4.1alpha02 - November 28, 2009
|
||||
Updated and distributed by Glenn Randers-Pehrson
|
||||
Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
|
||||
@@ -1655,7 +1659,7 @@ things.
|
||||
As of libpng version 1.2.9, png_set_expand_gray_1_2_4_to_8() was
|
||||
added. It expands the sample depth without changing tRNS to alpha.
|
||||
|
||||
As of libpng version 1.4.1alpha01, not all possible expansions are supported.
|
||||
As of libpng version 1.4.1alpha02, not all possible expansions are supported.
|
||||
|
||||
In the following table, the 01 means grayscale with depth<8, 31 means
|
||||
indexed with depth<8, other numerals represent the color type, "T" means
|
||||
@@ -1715,6 +1719,21 @@ images) is fully transparent, with
|
||||
|
||||
png_set_invert_alpha(png_ptr);
|
||||
|
||||
The PNG format only supports pixels with postmultiplied alpha.
|
||||
If you want to replace the pixels, after reading them, with pixels
|
||||
that have premultiplied color samples, you can do this with
|
||||
|
||||
png_set_premultiply_alpha(png_ptr, output_gamma);
|
||||
|
||||
where gamma is a double containing the gamma associated with the
|
||||
premultiplied pixels. The gamma of the input must also be available
|
||||
when the premultiplication takes place, via a gAMA chunk in the
|
||||
input file or via png_set_gAMA(). If neither is present, the
|
||||
premultiplication will assume input_gamma==(1/2.2)
|
||||
|
||||
If you do this, any input with a tRNS chunk will be expanded to
|
||||
have an alpha channel.
|
||||
|
||||
PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as
|
||||
they can, resulting in, for example, 8 pixels per byte for 1 bit
|
||||
files. This code expands to 1 pixel per byte without changing the
|
||||
@@ -3803,6 +3822,9 @@ after the png_malloc() to set the pointers to NULL.
|
||||
We added PNG_TRANSFORM_GRAY_TO_RGB to the available high-level
|
||||
input transforms.
|
||||
|
||||
We added the png_set_premultiply_alpha and
|
||||
png_do_read_premultiply_alpha() functions.
|
||||
|
||||
The call to png_do_chop() in pngrtran.c, which reduces 16-bit input
|
||||
files to 8-bit bit depth, was relocated ahead of the building
|
||||
of gamma tables. This allows us to build 8-bit tables instead
|
||||
@@ -3990,13 +4012,13 @@ Other rules can be inferred by inspecting the libpng source.
|
||||
|
||||
.SH XIII. Y2K Compliance in libpng
|
||||
|
||||
November 27, 2009
|
||||
November 28, 2009
|
||||
|
||||
Since the PNG Development group is an ad-hoc body, we can't make
|
||||
an official declaration.
|
||||
|
||||
This is your unofficial assurance that libpng from version 0.71 and
|
||||
upward through 1.4.1alpha01 are Y2K compliant. It is my belief that earlier
|
||||
upward through 1.4.1alpha02 are Y2K compliant. It is my belief that earlier
|
||||
versions were also Y2K compliant.
|
||||
|
||||
Libpng only has three year fields. One is a 2-byte unsigned integer that
|
||||
@@ -4167,7 +4189,7 @@ the first widely used release:
|
||||
1.4.0beta37-87 14 10400 14.so.14.0[.0]
|
||||
1.4.0rc01 14 10400 14.so.14.0[.0]
|
||||
1.4.0beta88-107 14 10400 14.so.14.0[.0]
|
||||
1.4.1alpha01 14 10401 14.so.14.0[.0]
|
||||
1.4.1alpha01-02 14 10401 14.so.14.0[.0]
|
||||
|
||||
Henceforth the source version will match the shared-library minor
|
||||
and patch numbers; the shared-library major version number will be
|
||||
@@ -4223,7 +4245,7 @@ possible without all of you.
|
||||
|
||||
Thanks to Frank J. T. Wojcik for helping with the documentation.
|
||||
|
||||
Libpng version 1.4.1alpha01 - November 27, 2009:
|
||||
Libpng version 1.4.1alpha02 - November 28, 2009:
|
||||
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
|
||||
Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
|
||||
|
||||
@@ -4246,7 +4268,7 @@ this sentence.
|
||||
|
||||
This code is released under the libpng license.
|
||||
|
||||
libpng versions 1.2.6, August 15, 2004, through 1.4.1alpha01, November 27, 2009, are
|
||||
libpng versions 1.2.6, August 15, 2004, through 1.4.1alpha02, November 28, 2009, are
|
||||
Copyright (c) 2004,2006-2007 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
|
||||
@@ -4345,7 +4367,7 @@ certification mark of the Open Source Initiative.
|
||||
|
||||
Glenn Randers-Pehrson
|
||||
glennrp at users.sourceforge.net
|
||||
November 27, 2009
|
||||
November 28, 2009
|
||||
|
||||
.\" end of man page
|
||||
|
||||
|
||||
@@ -1,6 +1,6 @@
|
||||
.TH LIBPNGPF 3 "November 27, 2009"
|
||||
.TH LIBPNGPF 3 "November 28, 2009"
|
||||
.SH NAME
|
||||
libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha01
|
||||
libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha02
|
||||
(private functions)
|
||||
.SH SYNOPSIS
|
||||
\fB#include <png.h>\fP
|
||||
@@ -211,6 +211,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.4.1alpha01
|
||||
|
||||
\fI\fB
|
||||
|
||||
\fBvoid png_do_read_premultiply_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
|
||||
|
||||
\fI\fB
|
||||
|
||||
\fBvoid png_do_read_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
|
||||
|
||||
\fI\fB
|
||||
|
||||
30
png.h
30
png.h
@@ -1,7 +1,7 @@
|
||||
|
||||
/* png.h - header file for PNG reference library
|
||||
*
|
||||
* libpng version 1.4.1alpha01 - November 27, 2009
|
||||
* libpng version 1.4.1alpha02 - November 28, 2009
|
||||
* Copyright (c) 1998-2009 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 1.4.1alpha01 - November 27, 2009: Glenn
|
||||
* libpng versions 0.97, January 1998, through 1.4.1alpha02 - November 28, 2009: Glenn
|
||||
* See also "Contributing Authors", below.
|
||||
*
|
||||
* Note about libpng version numbers:
|
||||
@@ -132,7 +132,7 @@
|
||||
* 1.4.0beta37-87 14 10400 14.so.14.0[.0]
|
||||
* 1.4.0rc01 14 10400 14.so.14.0[.0]
|
||||
* 1.4.0beta88-107 14 10400 14.so.14.0[.0]
|
||||
* 1.4.1alpha01 14 10401 14.so.14.0[.0]
|
||||
* 1.4.1alpha01-02 14 10401 14.so.14.0[.0]
|
||||
*
|
||||
* Henceforth the source version will match the shared-library major
|
||||
* and minor numbers; the shared-library major version number will be
|
||||
@@ -164,7 +164,7 @@
|
||||
*
|
||||
* This code is released under the libpng license.
|
||||
*
|
||||
* libpng versions 1.2.6, August 15, 2004, through 1.4.1alpha01, November 27, 2009, are
|
||||
* libpng versions 1.2.6, August 15, 2004, through 1.4.1alpha02, November 28, 2009, are
|
||||
* Copyright (c) 2004, 2006-2007 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:
|
||||
@@ -282,7 +282,7 @@
|
||||
* an official declaration.
|
||||
*
|
||||
* This is your unofficial assurance that libpng from version 0.71 and
|
||||
* upward through 1.4.1alpha01 are Y2K compliant. It is my belief that earlier
|
||||
* upward through 1.4.1alpha02 are Y2K compliant. It is my belief that earlier
|
||||
* versions were also Y2K compliant.
|
||||
*
|
||||
* Libpng only has three year fields. One is a 2-byte unsigned integer
|
||||
@@ -338,9 +338,9 @@
|
||||
*/
|
||||
|
||||
/* Version information for png.h - this should match the version in png.c */
|
||||
#define PNG_LIBPNG_VER_STRING "1.4.1alpha01"
|
||||
#define PNG_LIBPNG_VER_STRING "1.4.1alpha02"
|
||||
#define PNG_HEADER_VERSION_STRING \
|
||||
" libpng version 1.4.1alpha01 - November 27, 2009\n"
|
||||
" libpng version 1.4.1alpha02 - November 28, 2009\n"
|
||||
|
||||
#define PNG_LIBPNG_VER_SONUM 14
|
||||
#define PNG_LIBPNG_VER_DLLNUM 14
|
||||
@@ -353,7 +353,7 @@
|
||||
* PNG_LIBPNG_VER_STRING, omitting any leading zero:
|
||||
*/
|
||||
|
||||
#define PNG_LIBPNG_VER_BUILD 01
|
||||
#define PNG_LIBPNG_VER_BUILD 02
|
||||
|
||||
/* Release Status */
|
||||
#define PNG_LIBPNG_BUILD_ALPHA 1
|
||||
@@ -1332,17 +1332,22 @@ struct png_struct_def
|
||||
/* New member added in libpng-1.2.30 */
|
||||
png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
|
||||
|
||||
/* New member added in libpng-1.4.0 */
|
||||
/* New member added in libpng-1.2.41 */
|
||||
#ifdef PNG_IO_STATE_SUPPORTED
|
||||
png_uint_32 io_state PNG_DEPSTRUCT;
|
||||
#endif
|
||||
|
||||
/* New member added in libpng-1.4.1 */
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
float gamma_premultiply;
|
||||
#endif
|
||||
};
|
||||
|
||||
|
||||
/* This triggers a compiler error in png.c, if png.c and png.h
|
||||
* do not agree upon the version number.
|
||||
*/
|
||||
typedef png_structp version_1_4_1alpha01;
|
||||
typedef png_structp version_1_4_1alpha02;
|
||||
|
||||
typedef png_struct FAR * FAR * png_structpp;
|
||||
|
||||
@@ -1524,6 +1529,11 @@ extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
|
||||
extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
extern PNG_EXPORT(void,png_set_premultiply_alpha)
|
||||
PNGARG((png_structp png_ptr, double gamma));
|
||||
#endif
|
||||
|
||||
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
|
||||
/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
|
||||
extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
|
||||
|
||||
@@ -1,7 +1,7 @@
|
||||
|
||||
/* pngconf.h - machine configurable file for libpng
|
||||
*
|
||||
* libpng version 1.4.1alpha01 - November 27, 2009
|
||||
* libpng version 1.4.1alpha02 - November 28, 2009
|
||||
* For conditions of distribution and use, see copyright notice in png.h
|
||||
* Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
|
||||
@@ -523,6 +523,9 @@
|
||||
# ifndef PNG_NO_READ_INVERT_ALPHA
|
||||
# define PNG_READ_INVERT_ALPHA_SUPPORTED
|
||||
# endif
|
||||
# ifndef PNG_NO_READ_PREMULTIPLY_ALPHA
|
||||
# define PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
# endif
|
||||
# ifndef PNG_NO_READ_STRIP_ALPHA
|
||||
# define PNG_READ_STRIP_ALPHA_SUPPORTED
|
||||
# endif
|
||||
|
||||
31
pngpriv.h
31
pngpriv.h
@@ -1,7 +1,7 @@
|
||||
|
||||
/* pngpriv.h - private declarations for use inside libpng
|
||||
*
|
||||
* libpng version 1.4.1alpha01 - November 27, 2009
|
||||
* libpng version 1.4.1alpha02 - November 28, 2009
|
||||
* For conditions of distribution and use, see copyright notice in png.h
|
||||
* Copyright (c) 1998-2009 Glenn Randers-Pehrson
|
||||
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
|
||||
@@ -127,7 +127,8 @@
|
||||
/* 0x800000L Unused */
|
||||
#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
|
||||
#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
|
||||
/* 0x4000000L unused */
|
||||
#define PNG_PREMULTIPLY_ALPHA 0x4000000L /* Added to libpng-1.4.0 */
|
||||
/* by volker */
|
||||
/* 0x8000000L unused */
|
||||
/* 0x10000000L unused */
|
||||
/* 0x20000000L unused */
|
||||
@@ -551,6 +552,11 @@ PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
|
||||
png_bytep row, png_uint_32 flags));
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
PNG_EXTERN void png_do_read_premultiply_alpha
|
||||
PNGARG((png_row_infop row_info, png_bytep row));
|
||||
#endif
|
||||
|
||||
#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
|
||||
PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
|
||||
#endif
|
||||
@@ -944,9 +950,24 @@ extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
|
||||
#define png_debug2(l, m, p1, p2)
|
||||
#endif
|
||||
|
||||
#if 0
|
||||
extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
|
||||
#endif
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
# ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
|
||||
# define PNG_DIVIDE_BY_255(v) \
|
||||
((png_byte)(((png_uint_16)(v) + \
|
||||
(((png_uint_16)(v) + 128) >> 8) + 128) >> 8))
|
||||
# define PNG_DIVIDE_BY_65535(v) \
|
||||
((png_byte)(((png_uint_32)(v) + \
|
||||
(((png_uint_32)(v) + 32768L) >> 16) + 32768L) >> 16))
|
||||
# else
|
||||
# define PNG_DIVIDE_BY_255(v) (((png_uint_16)(v))/255)
|
||||
# define PNG_DIVIDE_BY_65535(v) (((png_uint_32)(v))/65535L)
|
||||
# endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
|
||||
|
||||
# define PNG_8_BIT_PREMULTIPLY(color,alpha) \
|
||||
PNG_DIVIDE_BY_255((color)*(alpha))
|
||||
# define PNG_16_BIT_PREMULTIPLY(color,alpha)\
|
||||
PNG_DIVIDE_BY_65535((color)*(alpha))
|
||||
#endif /* PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED */
|
||||
|
||||
/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
|
||||
|
||||
|
||||
106
pngrtran.c
106
pngrtran.c
@@ -1,7 +1,7 @@
|
||||
|
||||
/* pngrtran.c - transforms the data in a row for PNG readers
|
||||
*
|
||||
* Last changed in libpng 1.4.0 [November 27, 2009]
|
||||
* Last changed in libpng 1.4.0 [November 28, 2009]
|
||||
* Copyright (c) 1998-2009 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.)
|
||||
@@ -140,6 +140,26 @@ png_set_strip_alpha(png_structp png_ptr)
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
void PNGAPI
|
||||
png_set_premultiply_alpha(png_structp png_ptr, double gamma)
|
||||
{
|
||||
png_debug(1, "in png_set_premultiply_alpha");
|
||||
|
||||
if(png_ptr == NULL)
|
||||
return;
|
||||
png_ptr->transformations |=
|
||||
(PNG_PREMULTIPLY_ALPHA | PNG_EXPAND_tRNS);
|
||||
png_ptr->transformations |=
|
||||
PNG_EXPAND; /* This shouldn't be necessary */
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
/* Check for overflow */
|
||||
if (gamma == 0 || gamma > 21474.83)
|
||||
png_error(png_ptr, "Invalid gamma for premultiply");
|
||||
png_ptr->gamma_premultiply = (float)gamma;
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_DITHER_SUPPORTED
|
||||
/* Dither file to 8 bit. Supply a palette, the current number
|
||||
* of elements in the palette, the maximum number of elements
|
||||
@@ -1492,6 +1512,12 @@ png_do_read_transformations(png_structp png_ptr)
|
||||
(png_uint_32)png_ptr->filler, png_ptr->flags);
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
if (png_ptr->transformations & PNG_PREMULTIPLY_ALPHA)
|
||||
png_do_read_premultiply_alpha(&(png_ptr->row_info),
|
||||
png_ptr->row_buf + 1);
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
||||
if (png_ptr->transformations & PNG_INVERT_ALPHA)
|
||||
png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
||||
@@ -1978,6 +2004,84 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_PREMULTIPLY_ALPHA_SUPPORTED
|
||||
void /* PRIVATE */
|
||||
png_do_read_premultiply_alpha(png_row_infop row_info, png_bytep row)
|
||||
{
|
||||
png_debug(1, "in png_do_read_premultiply_alpha");
|
||||
|
||||
{
|
||||
png_uint_32 row_width = row_info->width;
|
||||
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
||||
{
|
||||
/* This premultiplies the pixels with the alpha channel in RGBA */
|
||||
if (row_info->bit_depth == 8)
|
||||
{
|
||||
png_bytep sp = row + row_info->rowbytes;
|
||||
png_bytep dp = sp;
|
||||
png_uint_16 a = 0;
|
||||
png_uint_32 i;
|
||||
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
a = *(--sp); --dp;
|
||||
sp--; *(--dp) = PNG_8_BIT_PREMULTIPLY((*sp), a);
|
||||
sp--; *(--dp) = PNG_8_BIT_PREMULTIPLY((*sp), a);
|
||||
sp--; *(--dp) = PNG_8_BIT_PREMULTIPLY((*sp), a);
|
||||
}
|
||||
}
|
||||
/* This premultiplies the pixels with the alpha channel in RRGGBBAA */
|
||||
else
|
||||
{
|
||||
png_uint_16p sp = (png_uint_16p)(row + row_info->rowbytes);
|
||||
png_uint_16p dp = sp;
|
||||
png_uint_32 a = 0;
|
||||
png_uint_32 i;
|
||||
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
a = *(--sp); --dp;
|
||||
sp--; *(--dp) = PNG_16_BIT_PREMULTIPLY((*sp), a);
|
||||
sp--; *(--dp) = PNG_16_BIT_PREMULTIPLY((*sp), a);
|
||||
sp--; *(--dp) = PNG_16_BIT_PREMULTIPLY((*sp), a);
|
||||
}
|
||||
}
|
||||
}
|
||||
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
||||
{
|
||||
/* This premultiplies the pixels with the alpha channel in GA */
|
||||
if (row_info->bit_depth == 8)
|
||||
{
|
||||
png_bytep sp = row + row_info->rowbytes;
|
||||
png_bytep dp = sp;
|
||||
png_uint_16 a = 0;
|
||||
png_uint_32 i;
|
||||
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
a = *(--sp); --dp;
|
||||
sp--; *(--dp) = PNG_8_BIT_PREMULTIPLY((*sp), a);
|
||||
}
|
||||
}
|
||||
/* This premultiplies the pixels with the alpha channel in GGAA */
|
||||
else
|
||||
{
|
||||
png_uint_16p sp = (png_uint_16p) (row + row_info->rowbytes);
|
||||
png_uint_16p dp = sp;
|
||||
png_uint_32 a = 0;
|
||||
png_uint_32 i;
|
||||
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
a = *(--sp); --dp;
|
||||
sp--; *(--dp) = PNG_16_BIT_PREMULTIPLY((*sp), a);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef PNG_READ_FILLER_SUPPORTED
|
||||
/* Add filler channel if we have RGB color */
|
||||
void /* PRIVATE */
|
||||
|
||||
Reference in New Issue
Block a user