libjpeg-turbo/libjpeg-turbo 1.4.1

on GitHub

Official binaries and source tarball are available at:
https://sourceforge.net/projects/libjpeg-turbo/files/1.4.1

Significant changes relative to 1.4.0:

1. tjbench now properly handles CMYK/YCCK JPEG files. Passing an argument of -cmyk (instead of, for instance, -rgb) will cause tjbench to internally convert the source bitmap to CMYK prior to compression, to generate YCCK JPEG files, and to internally convert the decompressed CMYK pixels back to RGB after decompression (the latter is done automatically if a CMYK or YCCK JPEG is passed to tjbench as a source image.) The CMYK<->RGB conversion operation is not benchmarked. NOTE: The quick & dirty CMYK<->RGB conversions that tjbench uses are suitable for testing only. Proper conversion between CMYK and RGB requires a color management system.

2. make test now performs additional bitwise regression tests using tjbench, mainly for the purpose of testing compression from/decompression to a subregion of a larger image buffer.

3. make test no longer tests the regression of the floating point DCT/IDCT by default, since the results of those tests can vary if the algorithms in question are not implemented using SIMD instructions on a particular platform. See the comments in Makefile.am for information on how to re-enable the tests and to specify an expected result for them based on the particulars of your platform.

4. The NULL color conversion routines have been significantly optimized, which speeds up the compression of RGB and CMYK JPEGs by 5-20% when using 64-bit code and 0-3% when using 32-bit code, and the decompression of those images by 10-30% when using 64-bit code and 3-12% when using 32-bit code.

5. Fixed an "illegal instruction" error that occurred when djpeg from a SIMD-enabled libjpeg-turbo MIPS build was executed with the -nosmooth option on a MIPS machine that lacked DSPr2 support. The MIPS SIMD routines for h2v1 and h2v2 merged upsampling were not properly checking for the existence of DSPr2.

6. Performance has been improved significantly on 64-bit non-Linux and non-Windows platforms (generally 10-20% faster compression and 5-10% faster decompression.) Due to an oversight, the 64-bit version of the accelerated Huffman codec was not being compiled in when libjpeg-turbo was built on platforms other than Windows or Linux. Oops.

7. Fixed an extremely rare bug in the Huffman encoder that caused 64-bit builds of libjpeg-turbo to incorrectly encode a few specific test images when quality=98, an optimized Huffman table, and the accurate integer forward DCT were used.

8. The Windows (CMake) build system now supports building only static or only shared libraries. This is accomplished by adding either -DENABLE_STATIC=0 or -DENABLE_SHARED=0 to the CMake command line.

9. TurboJPEG API functions will now return an error code if a warning is triggered in the underlying libjpeg API. For instance, if a JPEG file is corrupt, the TurboJPEG decompression functions will attempt to decompress as much of the image as possible, but those functions will now return -1 to indicate that the decompression was not entirely successful.

10. Fixed a bug in the MIPS DSPr2 4:2:2 fancy upsampling routine that caused a buffer overflow (and subsequent segfault) when decompressing a 4:2:2 JPEG image in which the right-most MCU was 5 or 6 pixels wide.