libjpeg-turbo

Significant changes relative to 3.1 beta1:

Fixed an issue in the TurboJPEG API whereby, when generating a lossless JPEG image with more than 8 bits per sample, specifying a point transform value greater than 7 resulted in an error ("Parameter value out of range") unless TJPARAM_PRECISION/TJ.PARAM_PRECISION was specified before TJPARAM_LOSSLESSPT/TJ.PARAM_LOSSLESSPT.

Fixed a regression introduced by 1.4 beta1[3] that prevented jpeg_set_defaults() from resetting the Huffman tables to default (baseline) values if Huffman table optimization or progressive mode was previously enabled in the same libjpeg instance.

Fixed an issue whereby lossless JPEG compression could not be disabled if it was previously enabled in a libjpeg or TurboJPEG instance. jpeg_set_defaults() now disables lossless JPEG compression in a libjpeg instance, and setting TJPARAM_LOSSLESS/TJ.PARAM_LOSSLESS to 0 now disables lossless JPEG compression in a TurboJPEG instance.

Significant changes relative to 3.0.4:

The libjpeg-turbo source tree has been reorganized to make it easier to find the README files, license information, and build instructions. The documentation for the libjpeg API library and associated programs has been moved into the doc/ subdirectory, all C source code and headers have been moved into a new src/ subdirectory, and test scripts have been moved into a new test/ subdirectory.

cjpeg no longer allows GIF input files to be converted into 12-bit-per-sample JPEG files. That was never a useful feature, since GIF images have at most 256 colors referenced from a palette of 8-bit-per-component RGB values.

Added support for lossless JPEG images with 2 to 15 bits per sample to the libjpeg and TurboJPEG APIs. When creating or decompressing a lossless JPEG image and when loading or saving a PBMPLUS image, functions/methods specific to 8-bit samples now handle 8-bit samples with 2 to 8 bits of data precision (specified using the data_precision field in jpeg_compress_struct or jpeg_decompress_struct or using TJPARAM_PRECISION/TJ.PARAM_PRECISION), functions/methods specific to 12-bit samples now handle 12-bit samples with 9 to 12 bits of data precision, and functions/methods specific to 16-bit samples now handle 16-bit samples with 13 to 16 bits of data precision. Refer to libjpeg.txt, usage.txt, and the TurboJPEG API documentation for more details.

All deprecated constants and methods in the TurboJPEG Java API have been removed.

TJBench command-line arguments are now more consistent with those of cjpeg, djpeg, and jpegtran. More specifically:
-copynone has been replaced with -copy none.
-fastdct has been replaced with -dct fast.
-fastupsample has been replaced with -nosmooth.
-hflip and -vflip have been replaced with -flip {horizontal|vertical}.
-limitscans has been replaced with -maxscans, which allows the scan limit to be specified.
-rgb, -bgr, -rgbx, -bgrx, -xbgr, -xrgb, and -cmyk have been replaced with -pixelformat {rgb|bgr|rgbx|bgrx|xbgr|xrgb|cmyk}.
-rot90, -rot180, and -rot270 have been replaced with -rotate {90|180|270}.
-stoponwarning has been replaced with -strict.
British spellings for gray (grey) and optimize (optimise) are now allowed.

The old command-line arguments are deprecated and will be removed in a future release. TJBench command-line arguments can now be abbreviated as well. (Where possible, the abbreviations are the same as those supported by cjpeg, djpeg, and jpegtran.)

Added a new TJBench option (-pixelformat gray) that can be used to test the performance of compressing/decompressing a grayscale JPEG image from/to a packed-pixel grayscale image.

Fixed an issue whereby, if TJPARAM_NOREALLOC was set, TurboJPEG compression and lossless transformation functions ignored the JPEG buffer size(s) passed to them and assumed that the JPEG buffer(s) had been allocated to a worst-case size returned by tj3JPEGBufSize(). This behavior was never documented, although the documentation was unclear regarding whether the JPEG buffer size should be specified if a JPEG buffer is pre-allocated to a worst-case size.

The TurboJPEG C and Java APIs have been improved in the following ways:
New image I/O methods (TJCompressor.loadSourceImage() and TJDecompressor.saveImage()) have been added to the Java API. These methods work similarly to the tj3LoadImage*() and tj3SaveImage*() functions in the C API.
The TurboJPEG lossless transformation function and methods now add restart markers to all destination images if TJPARAM_RESTARTBLOCKS/TJ.PARAM_RESTARTBLOCKS or TJPARAM_RESTARTROWS/TJ.PARAM_RESTARTROWS is set.
New functions/methods (tj3SetICCProfile() / TJCompressor.setICCProfile() / TJTransformer.setICCProfile() and tj3GetICCProfile() / TJDecompressor.getICCProfile()) can be used to embed and retrieve ICC profiles.
A new parameter (TJPARAM_SAVEMARKERS/TJ.PARAM_SAVEMARKERS) can be used to specify the types of markers that will be copied from the source image to the destination image during lossless transformation if TJXOPT_COPYNONE/TJTransform.OPT_COPYNONE is not specified.
A new convenience function/method (tj3TransformBufSize() / TJTransformer.bufSize()) can be used to compute the worst-case destination buffer size for a given lossless transform, taking into account cropping, transposition of the width and height, grayscale conversion, and the embedded or extracted ICC profile.

TJExample has been replaced with three programs (TJComp, TJDecomp, and TJTran) that demonstrate how to approximate the functionality of cjpeg, djpeg, and jpegtran using the TurboJPEG C and Java APIs.