java/doc/org/libjpegturbo/turbojpeg/YUVImage.html


Log

Author Commit Date CI Message
DRC df9dbff8 2023-11-11T12:25:03 TurboJPEG: New param to limit virt array mem usage This corresponds to max_memory_to_use in the jpeg_memory_mgr struct in the libjpeg API, except that the TurboJPEG parameter is specified in megabytes. Because this is 2023 and computers with less than 1 MB of memory are not a thing (at least not within the scope of libjpeg-turbo support), it isn't useful to allow a limit less than 1 MB to be specified. Furthermore, because TurboJPEG parameters are signed integers, if we allowed the memory limit to be specified in bytes, then it would be impossible to specify a limit larger than 2 GB on 64-bit machines. Because max_memory_to_use is a long signed integer, effectively we can specify a limit of up to 2 petabytes on 64-bit machines if the TurboJPEG parameter is specified in megabytes. (2 PB should be enough for anybody, right?) This commit also bumps the TurboJPEG API version to 3.0.1. Since the TurboJPEG API version no longer tracks the libjpeg-turbo version, it makes sense to increment the API revision number when adding constants, to increment the minor version number when adding functions, and to increment the major version number for a complete overhaul. This commit also removes the vestigial TJ_NUMPARAM macro, which was never defined because it proved unnecessary. Partially implements #735
DRC fc881ebb 2023-03-09T20:55:43 TurboJPEG: Implement 4:4:1 chrominance subsampling This allows losslessly transposed or rotated 4:1:1 JPEG images to be losslessly cropped, partially decompressed, or decompressed to planar YUV images. Because tj3Transform() allows multiple lossless transformations to be chained together, all subsampling options need to have a corresponding transposed subsampling option. (This is why 4:4:0 was originally implemented as well.) Otherwise, the documentation would be technically incorrect. It says that images with unknown subsampling types cannot be losslessly cropped, partially decompressed, or decompressed to planar YUV images, but it doesn't say anything about images with known subsampling types whose subsampling type becomes unknown if the image is rotated or transposed. This is one of those situations in which it is easier to implement a feature that works around the problem than to document the problem. Closes #659
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 9a146f0f 2023-01-06T10:29:10 TurboJPEG: Numerous documentation improvements - Wordsmithing, formatting, and grammar tweaks - Various clarifications and corrections, including specifying whether a particular buffer or image is used as a source or destination - Accommodate/mention features that were introduced since the API documentation was created. - For clarity, use "packed-pixel" to describe uncompressed source/destination images that are not planar YUV. - Use "row" rather than "line" to refer to a single horizontal group of pixels or component values, for consistency with the libjpeg API documentation. (libjpeg also uses "scanline", which is a more archaic term.) - Use "alignment" rather than "padding" to refer to the number of bytes by which a row's width is evenly divisible. This consistifies the documention of the YUV functions and tjLoadImage(). ("Padding" typically refers to the number of bytes added to each row, which is not the same thing.) - Remove all references to "the underlying codec." Although the TurboJPEG API originated as a cross-platform wrapper for the Intel Integrated Performance Primitives, Sun mediaLib, QuickTime, and libjpeg, none of those TurboJPEG implementations has been maintained since 2009. Nothing would prevent someone from implementing the TurboJPEG API without libjpeg-turbo, but such an implementation would not necessarily have an "underlying codec." (It could be fully self-contained.) - Use "destination image" rather than "output image", for consistency, or describe the type of image that will be output. - Avoid the term "image buffer" and instead use "byte buffer" to refer to buffers that will hold JPEG images, or describe the type of image that will be contained in the buffer. (The Java documentation doesn't use "byte buffer", because the buffer arrays literally have "byte" in front of them, and since Java doesn't have pointers, it is not possible for mere mortals to store any other type of data in those arrays.) - C: Use "unified" to describe YUV images stored in a single buffer, for consistency with the Java documentation. - Use "planar YUV" rather than "YUV planar". Is is our convention to describe images using {component layout} {colorspace/pixel format} {image function}, e.g. "packed-pixel RGB source image" or "planar YUV destination image." - C: Document the TurboJPEG API version in which a particular function or macro was introduced, and reorder the backward compatibility function stubs in turbojpeg.h alphabetically by API version. - C: Use Markdown rather than HTML tags, where possible, in the Doxygen comments.
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 739edeb8 2015-07-21T09:34:02 Further exception cleanup Use a new checked exception type (TJException) when passing through errors from the underlying C library. This gives the application a choice of catching all exceptions or just those from TurboJPEG. Throw IllegalArgumentException at the JNI level when arguments to the JNI function are incorrect, and when one of the TurboJPEG "utility" functions returns an error (because, per the C API specification, those functions will only return an error if one of their arguments is out of range.) Remove "throws Exception" from the signature of any methods that no longer pass through an error from the TurboJPEG C library. Credit Viktor for the new code Code formatting tweaks
DRC b3817dab 2015-07-14T20:42:52 Throw idiomatic unchecked exceptions from the Java classes and JNI wrapper if there is an unrecoverable error caused by incorrect API usage (such as illegal arguments, etc.), and throw Errors if there is an unrecoverable error at the C level (such as a failed malloc() call.) Change the behavior of the bailif0() macro in the JNI wrapper so that it doesn't throw an exception for an unexpected NULL condition. In fact, in all cases, the underlying JNI API function (such as GetFieldID(), etc.) will throw an Error on its own whenever it returns NULL, so our custom exceptions were never being thrown in that case anyhow. All we need to do is just detect the error and bail out of the C code. This also corrects a couple of formatting issues (semicolons aren't needed at the end of class definitions, and @Override should be specified for the methods we're overriding from super-classes, so the compiler can sanity-check that we're actually overriding a method and not declaring a new one.) git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1595 632fc199-4ca6-4c93-a231-07263d6284db
DRC 40dd3146 2014-08-17T12:23:49 Refactored YUVImage Java class so that it supports both unified YUV image buffers as well as separate YUV image planes; modified the JNI functions accordingly and added new helper functions to the TurboJPEG C API (tjPlaneWidth(), tjPlaneHeight(), tjPlaneSizeYUV()) to facilitate those modifications; changed potentially confusing "component width" and "component height" terms to "plane width" and "plane height" and modified variable names in turbojpeg.c to reflect this; numerous other documentation tweaks git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1360 632fc199-4ca6-4c93-a231-07263d6284db
DRC 493be617 2014-08-10T20:12:17 Clean up and consolidate notes regarding the YUV image format. This also corrects a factual error regarding the padding of the luminance plane-- because we now support 4:1:1, the component width is not necessarily padded to the nearest multiple of 2 if horizontal subsampling is used. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1342 632fc199-4ca6-4c93-a231-07263d6284db
DRC 7a6ed075 2014-03-17T11:14:52 Extend YUVImage class to allow reuse of the same buffer with different metadata; port TJBench changes that treat YUV encoding/decoding as an intermediate step of the JPEG compression/decompression pipeline rather than a separate test case; add YUV encode/decode tests to the Java version of tjbenchtest git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1184 632fc199-4ca6-4c93-a231-07263d6284db
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 ee443719 2014-03-16T22:59:51 This should have been checked in with the previous commit. git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1177 632fc199-4ca6-4c93-a231-07263d6284db