Joint Bi-level Image Experts Group

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.^[1][2][3]

Logo of Joint Bi-level Image Experts Group (as part of Joint Photographic Experts Group)

The Joint Bi-level Image Experts Group created the JBIG and JBIG2 standards.^[4] The group often meets jointly with the JPEG committee, which typically meets three times annually.^[5]

ISO/IEC JTC1 SC29 Working Group 1 (working together with ITU-T Study Group 16 – VCEG^[6] and previously also with Study Group 8 – SG8^[7][8][9]) is responsible for both JPEG and JBIG standards.^[10] It included two sub-groups: the Joint Photographic Experts Group (JPEG SG) and the Joint Bi-level Image experts Group (JBIG SG).^[4][1] 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).^[11] 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.^[12][11]

Published standards

JBIG have developed following standards, which were published by ISO/IEC and/or ITU-T:

Joint Photographic Experts Group - developed standards^[2][13]

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 also

• Joint Photographic Experts Group (JPEG)
• Moving Picture Experts Group (MPEG)