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[master] Imported from libpng-1.2.41beta08.tar

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Glenn Randers-Pehrson 2009-10-29 23:45:37 -05:00
parent 4b14b35208
commit 4f67b78853
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@ -1703,6 +1703,15 @@ images) is fully transparent, with
png_set_invert_alpha(png_ptr); 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);
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 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 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 files. This code expands to 1 pixel per byte without changing the
@ -3756,6 +3765,70 @@ selection of assembler code features:
We replaced all of these functions with simple stubs in libpng-1.2.20, We replaced all of these functions with simple stubs in libpng-1.2.20,
when the Intel assembler code was removed due to a licensing issue. when the Intel assembler code was removed due to a licensing issue.
These macros are deprecated:
PNG_READ_TRANSFORMS_NOT_SUPPORTED
PNG_PROGRESSIVE_READ_NOT_SUPPORTED
PNG_NO_SEQUENTIAL_READ_SUPPORTED
PNG_WRITE_TRANSFORMS_NOT_SUPPORTED
PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED
PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED
They have been replaced, respectively, by:
PNG_NO_READ_TRANSFORMS
PNG_NO_PROGRESSIVE_READ
PNG_NO_SEQUENTIAL_READ
PNG_NO_WRITE_TRANSFORMS
PNG_NO_READ_ANCILLARY_CHUNKS
PNG_NO_WRITE_ANCILLARY_CHUNKS
PNG_MAX_UINT was replaced with PNG_UINT_31_MAX. It has been
deprecated since libpng-1.0.16 and libpng-1.2.6.
The function
png_check_sig(sig, num)
was replaced with
!png_sig_cmp(sig, 0, num)
It has been deprecated since libpng-0.90.
The function
png_set_gray_1_2_4_to_8()
which also expands tRNS to alpha was replaced with
png_set_expand_gray_1_2_4_to_8()
which does not. It has been deprecated since libpng-1.0.18 and 1.2.9.
Functions png_set_benign_errors(), png_benign_error(), and
png_chunk_benign_error() were added.
Support for setting the maximum amount of memory that the application
will allocate for reading chunks was added, as a security measure.
The functions png_set_chunk_cache_max() and png_get_chunk_cache_max()
were added to the library.
We implemented support for I/O states. Added png_ptr member io_state, and
functions png_get_io_chunk_name() and png_get_io_state() in pngget.c
The png_calloc() function was added and is used in place of
of "png_malloc(); png_memset();" except in the case in png_read_png()
where the array consists of pointers; in this case a "for" loop is used
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
of 16-bit tables, when only 8-bit tables are needed. This avoids
wasting some computing resources when the application has called
the png_set_strip_16() function and encounters a 16-bit PNG file.
Checking for and reporting of errors in the IHDR chunk is more thorough.
.SH IX. (Omitted) .SH IX. (Omitted)
.SH X. Detecting libpng .SH X. Detecting libpng