java/doc/help-doc.html


Log

Author Commit Date CI Message
DRC fc01f467 2023-01-05T06:36:46 TurboJPEG 3 API overhaul (ChangeLog update forthcoming) - Prefix all function names with "tj3" and remove version suffixes from function names. (Future API overhauls will increment the prefix to "tj4", etc., thus retaining backward API/ABI compatibility without versioning each individual function.) - Replace stateless boolean flags (including TJ*FLAG_ARITHMETIC and TJ*FLAG_LOSSLESS, which were never released) with stateful integer parameters, the value of which persists between function calls. * Use parameters for the JPEG quality and subsampling as well, in order to eliminate the awkwardness of specifying function arguments that weren't relevant for lossless compression. * tj3DecompressHeader() now stores all relevant information about the JPEG image, including the width, height, subsampling type, entropy coding type, etc. in parameters rather than returning that information in its arguments. * TJ*FLAG_LIMITSCANS has been reimplemented as an integer parameter (TJ*PARAM_SCANLIMIT) that allows the number of scans to be specified. - Use the const keyword for all pointer arguments to unmodified buffers, as well as for both dimensions of 2D pointers. Addresses #395. - Use size_t rather than unsigned long to represent buffer sizes, since unsigned long is a 32-bit type on Windows. Addresses #24. - Return 0 from all buffer size functions if an error occurs, rather than awkwardly trying to return -1 in an unsigned data type. - Implement 12-bit and 16-bit data precision using dedicated compression, decompression, and image I/O functions/methods. * Suffix the names of all data-precision-specific functions with 8, 12, or 16. * Because the YUV functions are intended to be used for video, they are currently only implemented with 8-bit data precision, but they can be expanded to 12-bit data precision in the future, if necessary. * Extend TJUnitTest and TJBench to test 12-bit and 16-bit data precision, using a new -precision option. * Add appropriate regression tests for all of the above to the 'test' target. * Extend tjbenchtest to test 12-bit and 16-bit data precision, and add separate 'tjtest12' and 'tjtest16' targets. * BufferedImage I/O in the Java API is currently limited to 8-bit data precision, since the BufferedImage class does not straightforwardly support higher data precisions. * Extend the PPM reader to convert 12-bit and 16-bit PBMPLUS files to grayscale or CMYK pixels, as it already does for 8-bit files. - Properly accommodate lossless JPEG using dedicated parameters (TJ*PARAM_LOSSLESS, TJ*PARAM_LOSSLESSPSV, and TJ*PARAM_LOSSLESSPT), rather than using a flag and awkwardly repurposing the JPEG quality. Update TJBench to properly reflect whether a JPEG image is lossless. - Re-organize the TJBench usage screen. - Update the Java docs using Java 11, to improve the formatting and eliminate HTML frames. - Use the accurate integer DCT algorithm by default for both compression and decompression, since the "fast" algorithm is a legacy feature, it does not pass the ISO compliance tests, and it is not actually faster on modern x86 CPUs. * Remove the -accuratedct option from TJBench and TJExample. - Re-implement the 'tjtest' target using a CMake script that enables the appropriate tests, depending on the data precision and whether or not the Java API is part of the build. - Consolidate the C and Java versions of tjbenchtest into one script. - Consolidate the C and Java versions of tjexampletest into one script. - Combine all initialization functions into a single function (tj3Init()) that accepts an integer parameter specifying the subsystems to initialize. - Enable decompression scaling explicitly, using a new function/method (tj3SetScalingFactor()/TJDecompressor.setScalingFactor()), rather than implicitly using awkward "desired width"/"desired height" parameters. - Introduce a new macro/constant (TJUNSCALED/TJ.UNSCALED) that maps to a scaling factor of 1/1. - Implement partial image decompression, using a new function/method (tj3SetCroppingRegion()/TJDecompressor.setCroppingRegion()) and TJBench option (-crop). Extend tjbenchtest to test the new feature. Addresses #1. - Allow the JPEG colorspace to be specified explicitly when compressing, using a new parameter (TJ*PARAM_COLORSPACE). This allows JPEG images with the RGB and CMYK colorspaces to be created. - Remove the error/difference image feature from TJBench. Identical images to the ones that TJBench created can be generated using ImageMagick with 'magick composite <original_image> <output_image> -compose difference <diff_image>' - Handle JPEG images with unknown subsampling types. TJ*PARAM_SUBSAMP is set to TJ*SAMP_UNKNOWN (== -1) for such images, but they can still be decompressed fully into packed-pixel images or losslessly transformed (with the exception of lossless cropping.) They cannot be partially decompressed or decompressed into planar YUV images. Note also that TJBench, due to its lack of support for imperfect transforms, requires that the subsampling type be known when rotating, flipping, or transversely transposing an image. Addresses #436 - The Java version of TJBench now has identical functionality to the C version. This was accomplished by (somewhat hackishly) calling the TurboJPEG C image I/O functions through JNI and copying the pixels between the C heap and the Java heap. - Add parameters (TJ*PARAM_RESTARTROWS and TJ*PARAM_RESTARTBLOCKS) and a TJBench option (-restart) to allow the restart marker interval to be specified when compressing. Eliminate the undocumented TJ_RESTART environment variable. - Add a parameter (TJ*PARAM_OPTIMIZE), a transform option (TJ*OPT_OPTIMIZE), and a TJBench option (-optimize) to allow optimized baseline Huffman coding to be specified when compressing. Eliminate the undocumented TJ_OPTIMIZE environment variable. - Add parameters (TJ*PARAM_XDENSITY, TJ*PARAM_DENSITY, and TJ*DENSITYUNITS) to allow the pixel density to be specified when compressing or saving a Windows BMP image and to be queried when decompressing or loading a Windows BMP image. Addresses #77. - Refactor the fuzz targets to use the new API. * Extend decompression coverage to 12-bit and 16-bit data precision. * Replace the awkward cjpeg12 and cjpeg16 targets with proper TurboJPEG-based compress12, compress12-lossless, and compress16-lossless targets - Fix innocuous UBSan warnings uncovered by the new fuzzers. - Implement previous versions of the TurboJPEG API by wrapping the new functions (tested by running the 2.1.x versions of TJBench, via tjbenchtest, and TJUnitTest against the new implementation.) * Remove all JNI functions for deprecated Java methods and implement the deprecated methods using pure Java wrappers. It should be understood that backward API compatibility in Java applies only to the Java classes and that one cannot mix and match a JAR file from one version of libjpeg-turbo with a JNI library from another version. - tj3Destroy() now silently accepts a NULL handle. - tj3Alloc() and tj3Free() now return/accept void pointers, as malloc() and free() do. - The image I/O functions now accept a TurboJPEG instance handle, which is used to transmit/receive parameters and to receive error information. Closes #517
DRC dc4b9002 2017-11-16T20:43:12 TurboJPEG: Add alpha offset array/method Also, set the red/green/blue offsets for TJPF_GRAY to -1 rather than 0. It was undefined behavior for an application to use those arrays/methods with TJPF_GRAY anyhow, and this makes it easier for applications to programmatically detect whether a given pixel format has red, green, and blue components.
DRC 6ffed933 2014-03-16T23:12:25 Generate the Java documentation using javadoc 7, to improve readability. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1178 632fc199-4ca6-4c93-a231-07263d6284db
DRC ae92418c 2013-08-18T10:47:07 Add note regarding the fact that 4:4:0 lacks full SIMD support; Add an option for benchmarking 4:4:0 subsampling in TJBench; Wordsmithing; Disable timestamp in generated HTML files to make diffing and merging easier git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@1016 632fc199-4ca6-4c93-a231-07263d6284db
DRC f82b9f96 2013-08-18T10:39:30 Add note regarding the fact that 4:4:0 lacks full SIMD support; Add an option for benchmarking 4:4:0 subsampling in TJBench; Wordsmithing; Disable timestamp in generated HTML files to make diffing and merging easier git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1015 632fc199-4ca6-4c93-a231-07263d6284db
DRC fef9852d 2013-04-28T01:32:52 Extend the TurboJPEG Java API to support generating YUV images with arbitrary padding and to support image scaling when decompressing to YUV git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@975 632fc199-4ca6-4c93-a231-07263d6284db
DRC 65d4a46d 2013-04-27T01:06:52 Java doc tweaks git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.3.x@966 632fc199-4ca6-4c93-a231-07263d6284db
DRC fac3bea8 2012-09-24T02:27:55 Add a Java version of TJBench and extend the TurboJPEG Java API to support it (this involved adding a polymorphic method in TJCompressor that accepts x and y offsets into a larger buffer, similar to the previous modification that had been done to TJDecompressor.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@862 632fc199-4ca6-4c93-a231-07263d6284db
DRC 73d74c13 2012-06-29T23:46:38 Add flags to the TurboJPEG API that allow the caller to force the use of either the fast or the accurate DCT/IDCT algorithms in the underlying codec. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@851 632fc199-4ca6-4c93-a231-07263d6284db
DRC fd3aba35 2012-06-29T23:14:48 Added flags to the TurboJPEG API that allow the caller to force the use of either the fast or the accurate DCT/IDCT algorithms in the underlying codec. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/branches/1.2.x@849 632fc199-4ca6-4c93-a231-07263d6284db
DRC f659f43f 2012-06-06T08:41:06 Add x, y parameters to TJDecompressor so that it can be used to decompress to an arbitrary position in the destination image (TurboVNC needs this.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@832 632fc199-4ca6-4c93-a231-07263d6284db
DRC 67ce3b23 2011-12-19T02:21:03 Added new alpha channel colorspace constants/pixel formats, so applications can specify that they need the unused byte in a 4-component RGB output buffer set to 0xFF when decompressing. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@732 632fc199-4ca6-4c93-a231-07263d6284db
DRC 80803ae5 2011-12-15T13:12:59 "which"="that" git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@730 632fc199-4ca6-4c93-a231-07263d6284db
DRC f5467110 2011-09-20T05:02:19 Implement custom filter callback in Java git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@707 632fc199-4ca6-4c93-a231-07263d6284db
DRC 9b49f0e4 2011-07-12T03:17:23 Re-work TJBUFSIZE() to take into account the level of chrominance subsampling git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@668 632fc199-4ca6-4c93-a231-07263d6284db
DRC b2f9415a 2011-04-02T02:09:03 Slight refactor to put ScalingFactor into its own class (mainly because the $ in the class name was wreaking havoc on the build scripts, but also to add a few convenience methods to it) and to create a separate loader class so we can provide a .jar file with the MinGW distribution that loads the correct DLL git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@557 632fc199-4ca6-4c93-a231-07263d6284db
DRC 92549de2 2011-03-15T20:52:02 Java code cleanup + Java docs git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@518 632fc199-4ca6-4c93-a231-07263d6284db