Software Declarations Part 1 is titled "Digital Compression and Coding of Continuous-tone Still Images, Part 1: Requirements and guidelines" and has document numbers ISO/IEC IS 10918-1, ITU-T T.81. Part 2 is titled "Digital Compression and Coding of Continuous-tone Still Images, Part 2: Compliance testing" and has document numbers ISO/IEC IS 10918-2, ITU-T T.83. The JPEG standard does not specify all details of an interchangeable file format. For the omitted details, we follow the "JFIF" conventions, revision 1.02. JFIF version 1 has been adopted as ISO/IEC 10918-5 (05/2013) and Recommendation ITU-T T.871 (05/2011):
Information technology – Digital compression and coding of continuous-tone still images: JPEG File Interchange Format (JFIF). It is available as a free download in PDF file format from https://www.iso.org/standard/54989.html and http://www.itu.int/rec/T-REC-T.871. A PDF file of the older JFIF 1.02 specification is available at http://www.w3.org/Graphics/JPEG/jfif3.pdf. The TIFF 6.0 file format specification can be obtained from http://mirrors.ctan.org/graphics/tiff/TIFF6.ps.gz. The JPEG incorporation scheme found in the TIFF 6.0 spec of 3-June-92 has a number of serious problems. IJG does not recommend use of the TIFF 6.0 design (TIFF Compression tag 6).
Instead, we recommend the JPEG design proposed by TIFF Technical Note #2 (Compression tag 7). Copies of this Note can be obtained from http://www.ijg.org/files/. It is expected that the next revision of the TIFF spec will replace the 6.0 JPEG design with the Note's design. Although IJG's own code does not support TIFF/JPEG, the free libtiff library uses our library to implement TIFF/JPEG per the Note. ARCHIVE LOCATIONS ================== The "official" archive site for this software is www.ijg.org. The most recent released version can always be found there in directory "files". The JPEG FAQ (Frequently Asked Questions) article is a source of some general information about JPEG.
It is available at http://www.faqs.org/faqs/jpeg-faq. FILE FORMAT COMPATIBILITY ========================= This software implements ITU T.81 | ISO/IEC 10918 with some extensions from ITU T.871 | ISO/IEC 10918-5 (JPEG File Interchange Format-- see REFERENCES). Informally, the term "JPEG image" or "JPEG file" most often refers to JFIF or a subset thereof, but there are other formats containing the name "JPEG" that are incompatible with the DCT-based JPEG standard or with JFIF (for instance, JPEG 2000 and JPEG XR). This software therefore does not support these formats.
Indeed, one of the original reasons for developing this free software was to help force convergence on a common, interoperable format standard for JPEG files. JFIF is a minimal or "low end" representation. TIFF/JPEG (TIFF revision 6.0 as modified by TIFF Technical Note #2) can be used for "high end" applications that need to record a lot of additional data about an image. TO DO ====== Please send bug reports, offers of help, etc. to jpeg-info@jpegclub.org. Software Declarations I/O 14 Version: 1.2.0