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Jbigtopnm User Manual(0)                              Jbigtopnm User Manual(0)



NAME
       jbigtopnm - JBIG to PNM image file converter


SYNOPSIS
       jbigtopnm [options] [input-file [output-file]]


DESCRIPTION
       This program is part of Netpbm(1).

       jbigtopnm  reads a JBIG bi-level image entity (BIE) from a file or standard input, decompresses it, and outputs
       a PBM or PGM file.  If the input has one plane, or you choose just one plane of it, the output is PBM.   Other-
       wise, the output is PGM.

       JBIG  is  a  highly  effective lossless compression algorithm for bi-level images (one bit per pixel), which is
       particularly suitable for scanned document pages.

       A JBIG encoded image can be stored in several resolutions in one or several BIEs. All resolution layers  except
       the  lowest  one are stored efficiently as differences to the next lower resolution layer.  You can use options
       -x and -y to stop the decompression at a specified maximal output image size.  The input file  can  consist  of
       several concatenated BIEs which contain different increasing resolution layers of the same image.


OPTIONS
       -x number
              Decode  only  up to the largest resolution layer which is still not more than number pixels wide.  If no
              such resolution layer exists, then use the smallest one available.


       -y number
              Decode only up to the largest resolution layer which is still not more than number pixels high.   If  no
              such  resolution  layer exists, then use the smallest one available.  You can also use options -x and -y
              together which selects the largest layer that satisfies both limits.


       -b     Use binary values instead of Gray code words in order to decode pixel values  from  multiple  bitplanes.
              This  option  has  effect  only if the input has more than one bitplane and you don't select just one of
              those bitplanes.  Note that the decoder has to be used in the same mode as the encoder and cannot deter-
              mine from the BIE, whether Gray or binary code words were used by the encoder.


       -d     Diagnose  a  BIE.   With this option, jbigtopnm only prints a summary of the header information found in
              the input file and then exits.


       -p number
              If the input contains multiple bitplanes, then extract only the specified single plane as  a  PBM  file.
              The first plane has number 0.




STANDARDS
       This  program  implements  the  JBIG  image  coding  algorithm  as  specified  in  ISO/IEC 11544:1993 and ITU-T
       T.82(1993).


AUTHOR
       jbigtopnm is based on the JBIG library by Markus Kuhn, part of his JBIG-KIT package .  The jbgtopbm program  is
       part of the JBIG-KIT package.

       jbigtopnm is part of the Netpbm package of graphics tools.


SEE ALSO
       pnm(1), pnmtojbig(1)


LICENSE
       If you use jbigtopnm, you are using various patents, particularly on its arithmetic encoding method, and in all
       probability you do not have a license from the patent owners to do so.



netpbm documentation           19 November 2003       Jbigtopnm User Manual(0)