Ijg JPEG function library: file listIjg JPEG function library: file list copyright (c) 1991-1996, Thomas G. Lane. This article is part of the independent JPEG group software. For how to distribute and use readme files, see the README files issued along with this database. This document is a guide to the files in the published ijg JPEG library. The released version includes a specialized JPEG library and two additional applications ("cjpeg" and "djpeg "), these two programs use the JPEG library to compress images in other formats into JPEG formats and decompress JPEG images into other formats. The third-party application "mongotran" applies this library for Lossless conversion between JPEG and other formats. There are two independent applications: "rdjpgcom" and "wrjpgcom ". JPEG function library ==================== include file: the data and function declaration output in the jpeglib. h JPEG library. Jconfig. h configuration declaration. Note: This file does not exist in this release and will be generated during installation. Jmorecfg. h Additional configuration Declaration; No changes are required during standard installation. Jerror. h declares JPEG library errors and traces the message code. The core include files used by all jinclude. h ijg. c files are used to associate system include files. The internal data structure of the jpegint. h JPEG database. The private declaration required by the jchuff. h Huffman encoding module. The private declaration required by the jdhuff. h Huffman decoding module is the private declaration required by the jdct. h forward and reverse DCT subsystems. The private declaration required by the jmemsys. h memory management subsystem. Jversion. h version information. The application JPEG library must contain jpeglib. H (it references jconfig. h and jmorecfg. h ). Jerror. H is optional. If the application needs to refer to some JPEG error codes. Other header files are used inside the library and should not be referenced by applications. (Cjpeg/djpeg and other applications use jinclude. h to improve the portability of their functions in the entire ijg release. Most other applications will directly reference the system include files they need, and some do not need to include jinclude. H .) C-source code files: these files contain most functions that can be directly called in applications: jcapimin. C-Application Programming Interface: compressed core subroutines. Jcapistd. c Application Programming Interface: Standard compression. Jdapimin. c Application Programming Interface: extract the core subroutine. Jdapistd. c Application Programming Interface: Standard decompression. Jcomapi. c Application Programming Interface: Common subroutines for compression and decompression. Jcparam. C. Set the Helper subroutine for the compression parameter. Jctrans. C is used to convert the compressed library program and API of the encoding (transcoding. Jdtrans. C is used to extract the library program and API for transcoding (transcoding. Library files related to compression: jcinit. c initialization: determine which other modules to use. Jcmaster. C master control: establishes and interacts with the sequence logic. Jcmainct. C master buffer control (Preprocessor => JPEG compressors ). Jcprepct. c Preprocessor buffer control. Buffer Control of jccoefct. c DCT coefficient cache. Jccolor. c color space conversion. Download Sample jcsample. C. Jcdctmgr. c DCT Management (selection and control of DCT Implementation). jfdctint. c uses the forward DCT of the slow-and high-precision Integer method. Jfdctfst. c uses the forward DCT of the fast-but-low-precision Integer method. Jfdctflt. c uses the forward DCT of the floating point algorithm. Jchuff. c sequence (sequential) JPEG Huffman entropy encoding. Jcphuff. C: Progressive JPEG Huffman entropy encoding. Jcmarker. c JPEG marker writing. Jdatadst. c manages the data destination output by stdio. Master Control of the database file jdmaster. C related to decompression: determine which other modules to use. Jdinput. c input control: controls the input processing module. Jdmainct. C master buffer control (Preprocessor => JPEG compression ). Buffer Control of jdcoefct. c DCT coefficient cache. The jdpostct. c postprocessor buffer controls the Huffman entropy Decoding of jdmarker. c JPEG marker reading. jdhuff. c sequence (sequential) JPEG. Jdphuff. c implements progressive JPEG Huffman entropy decoding. Jddctmgr. c IDCT Management (selection and control of idct dct implementation ). Jidctint. c uses the reverse DCT of the slow-and high-precision Integer method. Jidctfst. c uses the forward DCT of the fast-but-low-precision Integer method .. Jidctflt. c uses the reverse DCT of the floating point algorithm. The jidctred. c carries reverse DCT that reduces the output size. Download Sample jdsample. C. Jdcolor. c color space conversion. Download Sample/color space conversion for jdmerge. c Merge (fast, low quality ). Jquant1.c one-pass Color quantization using a fixed-spacing colormap. jquant2.c two-pass Color quantization using a custom-generated colormap. also handles one-pass quantization to an externally given map. jdatasrc. c stdio input data source management. Supported files for compression and decompression: jerror. C standard error handling subroutine (can be replaced by an application ). Jmemmgr. C system independent (more or less) Memory Management Code. Other tool subroutines in jutils. C. Jmemmgr. c depends on the System-independent memory management module. The ijg release contains the following system-independent modules: jmemnobs. c "no backing store (no backup storage)": Suppose enough virtual memory exists. Jmemansi. c uses the ANSI standard function tmpfile () to generate temporary files. Jmemname. C: create a temporary file with the file name generated by the program. Jmemdos. C is a customer implementation for MS-DOS (for a 16-bit environment only): Can be used to expand and expand memory and temporary files. Jmemmac. C is a customer implementation provided by Apple's Macintosh. To be accurate, only one system-related module should be added during JPEG library installation. (See install.doc to obtain the required prompt ). On a general system, you may find it worthwhile to create a particularly system-related memory management. Non-C source code file: jmemdosa. ASM supports 80x86 assembly code of jmemdos. C; only used for MS-DOS-specified JPEG library configuration. Cjpeg/djpeg/export Tran ============================ include file: cdjpeg. H is the declaration of the module shared by cjpeg/djpeg/mongotran. Cderror. H is an additional error and debugging message code such as cjpeg. In transupp. H, transupp. C is used to support the statement of sequence Tran. C source code file: the main program of cjpeg. c cjpeg. Main Program of djpeg. c djpeg. Using Tran. C using Tran's main program. The tool functions used by the cdjpeg. C applications. Rdcolmap. c reads the code of the colormap file on the "-map" Switch of djpeg. Rdswitch. C is used to process more complex switch code of cjpeg and also to compile Tran. Code supported by transupp. C. Tran: Lossless Image operations. Cjpeg rdbmp. c BMP file input. Rdgif. c GIF file input (only a prototype at present ). Rdppm. c ppm/PGM file input. Rdrle. c Utah RLE file input. The rdtarga. c Targa file is input to the module where djpeg writes the image file: wrbmp. c BMP file output. Wrgif. c GIF file output (only a ing of the file's predecessor ). Wrppm. c ppm/PGM file output. Wrrle. c Utah RLE file output. Wrtarga. c Targa file output. Rdjpgcom/wrjpgcom ====================== C source code file: rdjpgcom. c independent rdjpgcom application. Wrjpgcom. c independent wrjpgcom application. These programs do not need to depend on the ijg library. But they actually use jconfig. h and jinclude. h to improve portability. Attached file ======================= documentation (see readme for a guide to the documentation files): readme main document file. *. Doc other document files. *. 1 Unix manual document format. A collection of changes from change. Log version to version. Example. C. Call the example program of the JPEG library. Configuration/installation files and programs (see install. Do for more information): Configure runs the automatically configured Unix shell script under UNIX. Scripts (using GNU libtool) for ltconfig configuration. ltmain. shconfig. guessconfig. subinstall-SH for installation of shell scripts prepared for Unix systems that lack shell. Ckconfig. C is used to generate a jconfig. H program on a non-Unix system. Jconfig.doc is used to manually generate a jconfig. h template. Makefile. * Sample makefiles for a specific system. Jconfig. * Sample jconfig. h for a specific system. Ansi2knr. c de-ansifier for pre-ansi c compilers (courtesy of L. peter Deutsch and Aladdin cancises ). test file (see install.doc for test process): test *. * Source images and compressed files used for testing, which are binary files rather than text files
