JBIG
Filename extension |
.jbg, .jbig |
---|---|
Image file formats | |
Extended to | JBIG2 |
Standards | ISO/IEC 11544, ITU-T Recommendations T.82, T.85 |
JBIG is an early
JBIG is based on a form of arithmetic coding developed by IBM (known as the Q-coder) that also uses a relatively minor refinement developed by Mitsubishi, resulting in what became known as the QM-coder. It bases the probability estimates for each encoded bit on the values of the previous bits and the values in previous lines of the picture. JBIG also supports progressive transmission, which generally incurs a small overhead in bit rate (around 5%).
Patents
Doubts about patent licence requirements for JBIG1 implementations by IBM, Mitsubishi and AT&T prevented the codec from being widely implemented in open-source software.[2] For example, as of 2012, none of the commonly used web browsers supported it. Since 2012, there are now no more JBIG1 patents in force – the last ones to expire were Mitsubishi's patents in Canada and Australia (on 25 February 2011) and in the United States (on 4 April 2012).[2][3]
See also
References
- ISBN 978-1-4302-6712-6.
- ^ a b "JBIG1 patent information". www.cl.cam.ac.uk.
- ^ "archive.ph". archive.ph. Archived from the original on 2013-02-22. Retrieved 2023-01-21.
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