JBIG

JBIG is an early standard for lossless compression of digital images .

The abbreviation is an acronym of the Joint Bi-level Image Experts Group , which is part of the Joint Photographic Experts Group, which is responsible for the JPEG process . It includes experts from several national standardization organizations.

The image format was published in March 1993 as ISO / IEC standard 11544 and ITU-T recommendation T.82. A new two-step algorithm called JBIG2 has now been developed; the forerunner has since been called JBIG1 . JBIG was specially developed for binary images such as faxes , but can also be used for other images. Usually it compresses 20% to 50% better than the group 4 fax standard, in special cases up to 30 times more.

JBIG uses an entropy coding algorithm patented by IBM called Q-Coder ( arithmetic coding ). It is based on probabilities of each bit with respect to the previous bit and the previous picture line. In order to enable the compression and decompression of images in the scanning direction, the following bits are not taken into account. JBIG also supports the progressive image structure with an approximately 5% higher data requirement.

Web links

Student thesis about JBIG1 and its JBIG-KIT implementation , 1995 (PDF file; 455 kB)
JBIG Homepage (Engl.)
JBIG-KIT - a free C implementation of a JBIG encoder and decoder

Individual evidence

↑ Shahriar Akramullah: Video Coding Standards . In: Digital Video Concepts, Methods, and Metrics . Apress, 2014, ISBN 978-1-4302-6712-6 , pp. 55-100 , doi : 10.1007 / 978-1-4302-6713-3_3 (English, springer.com ).

[Standards-1] Shahriar Akramullah: Video Coding Standards . In: Digital Video Concepts, Methods, and Metrics . Apress, 2014, ISBN 978-1-4302-6712-6 , pp. 55-100 , doi : 10.1007 / 978-1-4302-6713-3_3 (English, springer.com ).