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Wordsmithing & clarifications

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git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1363 632fc199-4ca6-4c93-a231-07263d6284db
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DRC
2014-08-20 16:02:49 +00:00
parent 25651f6eb5
commit 9c318c0884
1 changed files with 14 additions and 13 deletions
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ChangeLog.txt
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@@ -13,18 +13,18 @@ compatibility, since 4:1:1 is not fully accelerated in libjpeg-turbo and has no
significant advantages relative to 4:2:0.
-- CMYK images are now supported. This feature allows CMYK source images to be
compressed to YCCK JPEGs and YCCK or CMYK JPEGs to be decompressed to CMYK
destination images. Conversion between CMYK and RGB or YUV images is not
supported. Such conversion requires a color management system and is out of
scope for a codec library.
destination images. Conversion between CMYK/YCCK and RGB or YUV images is not
supported. Such conversion requires a color management system and is thus out
of scope for a codec library.
-- The handling of YUV images in the Java API has been significantly refactored
and should now be much more intuitive.
-- The Java API now supports encoding a YUV image from an arbitrary position in
a large image buffer.
-- All of the YUV functions now have a corresponding function that operates on
separate image planes instead of a unified image buffer. This allows for
compressing/decoding a YUV image from or decompressing/encoding a YUV image to
an arbitrary position in a larger YUV image. It also allows for handling YUV
formats that swap the order of the U and V planes.
compressing/decoding from or decompressing/encoding to a subregion of a larger
YUV image. It also allows for handling YUV formats that swap the order of the
U and V planes.
[2] Added SIMD acceleration for DSPr2-capable MIPS platforms. This speeds up
the compression of full-color JPEGs by 70-80% on such platforms and
@@ -51,7 +51,7 @@ Android devices that were tested, two demonstrated a small overall performance
loss (~3-4% on average) with ARMv6 code and a small gain (also ~3-4%) with
ARMv7 code when enabling this new feature, but the other two devices
demonstrated a significant overall performance gain with both ARMv6 and ARMv7
code (~10-20%.) Actual mileage may vary.
code (~10-20%) when enabling the feature. Actual mileage may vary.
[6] Worked around an issue with Visual C++ 2010 and later that caused incorrect
pixels to be generated when decompressing a JPEG image to a 256-color bitmap,
@@ -70,10 +70,9 @@ slower.
[8] Added a new output colorspace (JCS_RGB565) to the libjpeg API that allows
for decompressing JPEG images into RGB565 (16-bit) pixels.
[9] Numerous obsolete features, such as support for compilers that can't
handle prototypes and support for the MS-DOS memory model, were removed from
the libjpeg code, greatly improving its readability and making it easier to
maintain and extend.
[9] Numerous obsolete features, such as support for non-ANSI compilers and
support for the MS-DOS memory model, were removed from the libjpeg code,
greatly improving its readability and making it easier to maintain and extend.
[10] Fixed a segfault that occurred when calling output_message() with msg_code
set to JMSG_COPYRIGHT.
@@ -83,14 +82,16 @@ characters to be passed on the command line, which was causing it to generate
incorrect JPEG files.
[12] Fixed a bug in the build system that was causing the Windows version of
wrjpgcom to be built using the rdjpgcom code.
wrjpgcom to be built using the rdjpgcom source code.
[13] Restored 12-bit-per-component JPEG support. A 12-bit version of
libjpeg-turbo can now be built by passing an argument of --with-12bit to
configure (Unix) or -DWITH_12BIT=1 to cmake (Windows.) 12-bit JPEG support is
included only for convenience. Enabling this feature disables all of the
performance features in libjpeg-turbo, as well as arithmetic coding and the
TurboJPEG API. The resulting library behaves no differently than libjpeg v6b.
TurboJPEG API. The resulting library still contains the other libjpeg-turbo
features (such as the colorspace extensions), but in general, it performs no
faster than libjpeg v6b.
[14] Added ARM 64-bit SIMD acceleration for the YCC-to-RGB color conversion
and IDCT algorithms (both are used during JPEG decompression.) For unknown