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Top Document: Graphics File Formats FAQ (Part 3 of 4): Where to Get File Format Specifications
Previous Document: IV-VRML - Inventor VRML Format
Next Document: JCAMP
JBIG - Joint Bilevel Image Group
Type: Compression Method
Extension: Not specified by specification
Version:
Compression: JBIG
Color Depth: 1-bit (see text)
Maintainer: ISO, IEC and ITU
Specification:
JBIG is a lossless method for compressing black and white (1-bit) raster
image data. Its primary benefit is as a method for transmitting bi-level
image data across a communications channel. JBIG's progressive encoding
scheme allows lower resolution version of the image to be sent first,
followed by higher resolution images which build on the previously
transmitted data (e.g. 75, 150, 300, 450, and 600 DPI). This capability makes
JBIG ideal for replacing less-efficient document imaging transmissions
methods, such as CCITT Group 3 & 4, but thus far JBIG has not been marketed
in such a way as to make this possible.
There is no official JBIG file format. You just dump a JBIG data stream into
a disk for tape file, give it the extension JBG or JBIG, and you have a JBIG
file.
JBIG is jointly sponsored by the ITU (CCITT) and ISO/IEC JTCI/SC29
committees. The JBIG standard may be found in the following documents:
Information technology -- Coded representation of picture and audio
information -- Progressive bi-level image compression, ISO/IEC 11544:1993
ITU/CCITT Recommendation T.82
Top Document: Graphics File Formats FAQ (Part 3 of 4): Where to Get File Format Specifications
Previous Document: IV-VRML - Inventor VRML Format
Next Document: JCAMP
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Send corrections/additions to the FAQ Maintainer:
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Last Update October 22 2009 @ 05:25 AM