NAME

       jbigtopnm - JBIG to PNM image file converter

SYNOPSIS

       jbigtopnm [-xmax] [-ymax] [-binary] [-diagnose] [-plane] [input-file [output-file]]

       Minimum  unique  abbreviation of option is acceptable.  You may use double hyphens instead
       of single hyphen to denote options.  You may use white space in place of the  equals  sign
       to separate an option name from its value.

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.  Otherwise, 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

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see
        Common  Options  ⟨index.html#commonoptions⟩ ), jbigtopnm recognizes the following command
       line options:

       Before Netpbm 10.85 (December 2018), only single-character single-hyphen abbreviations  of
       the options are accepted.

       -xmax 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.

       -ymax 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.

       -binary
              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 determine from the BIE,
              whether Gray or binary code words were used by the encoder.

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

       -plane 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
       ⟨http://www.cl.cam.ac.uk/~mgk25/jbigkit/⟩ .  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

       There was at one time concern about the need for patent licenses to use jbigtopnm, but any
       relevant patents expired by 2012.

DOCUMENT SOURCE

       This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The  master
       documentation is at

              http://netpbm.sourceforge.net/doc/jbigtopnm.html