JBIG: Difference between revisions
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{{This article is about|a bi-level image compression scheme. For the designers of this scheme see [[Joint Bi-level Image Experts Group]]}} |
{{This article is about|a bi-level image compression scheme. For the designers of this scheme see [[Joint Bi-level Image Experts Group]]}} |
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'''JBIG''' is a [[Lossless data compression|lossless]] [[image compression]] standard from the [[Joint Bi-level Image Experts Group]], standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. Now that the newer [[binary image|bi-level image]] compression standard [[JBIG2]] has been released, JBIG is also known as '''JBIG1'''. JBIG was designed for compression of |
'''JBIG''' is a [[Lossless data compression|lossless]] [[image compression]] standard from the [[Joint Bi-level Image Experts Group]], standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. Now that the newer [[binary image|bi-level image]] compression standard [[JBIG2]] has been released, JBIG is also known as '''JBIG1'''. JBIG was designed for compression of binary images, particularly for [[facsimile|faxes]], but can also be used on other images. In most situations JBIG offers between a 20% and 50% increase in compression efficiency over the [[Group 4 (fax)|Fax Group 4]] standard, and in some situations, it offers a 30-fold improvement. |
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JBIG uses a form of [[arithmetic coding]] patented by [[IBM]] known as the Q-coder. It bases the probabilities of each bit on the previous bits and the previous lines of the picture. In order to allow compressing and decompressing images in scanning order, it does not reference future bits. JBIG also supports progressive transmission with small (around 5%) overheads. |
JBIG uses a form of [[arithmetic coding]] patented by [[IBM]] known as the Q-coder. It bases the probabilities of each bit on the previous bits and the previous lines of the picture. In order to allow compressing and decompressing images in scanning order, it does not reference future bits. JBIG also supports progressive transmission with small (around 5%) overheads. |
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* [http://www.compression-links.info/JBIG List of JBIG related resources] |
* [http://www.compression-links.info/JBIG List of JBIG related resources] |
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[[Category:Lossless compression algorithms]] |
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[[Category:Lossy compression algorithms]] |
[[Category:Lossy compression algorithms]] |
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[[Category:Graphics file formats]] |
[[Category:Graphics file formats]] |
Revision as of 08:05, 11 November 2005
JBIG is a lossless image compression standard from the Joint Bi-level Image Experts Group, standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. Now that the newer bi-level image compression standard JBIG2 has been released, JBIG is also known as JBIG1. JBIG was designed for compression of binary images, particularly for faxes, but can also be used on other images. In most situations JBIG offers between a 20% and 50% increase in compression efficiency over the Fax Group 4 standard, and in some situations, it offers a 30-fold improvement.
JBIG uses a form of arithmetic coding patented by IBM known as the Q-coder. It bases the probabilities of each bit on the previous bits and the previous lines of the picture. In order to allow compressing and decompressing images in scanning order, it does not reference future bits. JBIG also supports progressive transmission with small (around 5%) overheads.
External links
- JBIG-KIT – a free C implemenentation of the JBIG encoder and decoder
- List of JBIG related resources