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