The Joint Bi-level Image Experts Group (JBIG) was a group of experts nominated by national standards bodies and major companies to work to produce standards for bi-level image coding. The "joint" refers to its status as a committee working on both ISO and ITU-T standards. It was one of two sub-groups of ISO/IEC Joint Technical Committee 1, Subcommittee 29, Working Group 1 (ISO/IEC JTC 1/SC 29/WG 1), whose official title is Coding of still pictures.<ref name="sc29-wg1">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="jpeg-sc29">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The Joint Bi-level Image Experts Group created the JBIG and JBIG2 standards.<ref name="jpeg-jbig">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The group often meets jointly with the JPEG committee, which typically meets three times annually.<ref name="jpeg-work">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
ISO/IEC JTC1 SC29 Working Group 1 (working together with ITU-T Study Group 16 – VCEG<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and previously also with Study Group 8 – SG8<ref>Template:Citation</ref><ref>Template:Citation</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>) is responsible for both JPEG and JBIG standards.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It included two sub-groups: the Joint Photographic Experts Group (JPEG SG) and the Joint Bi-level Image experts Group (JBIG SG).<ref name="jpeg-jbig" /><ref name="sc29-wg1" /> After completing the 2019 edition of the JBIG2 standard, the JBIG subgroup was closed and its maintenance responsibilities were assigned to the general JPEG group.
In the mid-1980s, both CCITT (now ITU-T) and ISO had standardization groups for image coding: CCITT Study Group (SG) VIII (Telematic Services) and ISO TC97 SC2 WG8 (Coding of Audio and Picture Information).<ref name="chiariglione-jpeg-history">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They were historically targeted on image communication. In 1986, it was decided to create the Joint (CCITT/ISO) Photographic Expert Group. In 1988, it was decided to create the Joint (CCITT/ISO) Bi-level Image Group – JBIG.<ref>Template:Citation</ref><ref name="chiariglione-jpeg-history" />
Published standardsEdit
JBIG have developed following standards, which were published by ISO/IEC and/or ITU-T:
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| Common Name | Part | First public release date (First edition) | ISO/IEC Number | ITU Number | Formal Title |
|---|---|---|---|---|---|
| JBIG1 | 1993 | ISO/IEC 11544 | ITU-T Recommendations T.82, T.85 | Information technology – Coded representation of picture and audio information – Progressive bi-level image compression | |
| JBIG2 | 2001 | ISO/IEC 14492 | ITU-T Recommendations T.88, T.89 | Information technology – Lossy/lossless coding of bi-level images |
Note: The published JBIG2 standard was revised by three later amendments, which were consolidated into the current (2019) edition.
See alsoEdit
- Joint Photographic Experts Group (JPEG)
- Moving Picture Experts Group (MPEG)
