Joint Bi-level Image Experts Group
The Joint Bi-level Image Experts Group (JBIG) is 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. The 'official' title of the committee is ISO/IEC JTC1 SC29 Working Group 1, and is responsible for both JPEG and JBIG standards.
JBIG have developed IS 11544 (ITU-T T.82) for the lossless compression of a bi-level image. It can also be used for coding greyscale and colour images with limited numbers of bits per pixel. It can be seen as a form of facsimile encoding, similar to Group 3 or Group 4 fax, offering between 20 and 80% improvement in compression over these methods (about 20 to one over the original uncompressed digital bit map).
JBIG compression yields smaller image files than TIFF G4, especially when the images are speckled or dithered.
