jbigtopnm(1)

1Jbigtopnm User Manual(0)                              Jbigtopnm User Manual(0)
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NAME

6       jbigtopnm - JBIG to PNM image file converter
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SYNOPSIS

10       jbigtopnm [options] [input-file [output-file]]
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DESCRIPTION

14       This program is part of Netpbm(1).
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16       jbigtopnm reads a JBIG bi-level image entity (BIE) from a file or stan‐
17       dard input, decompresses it, and outputs a PBM or  PGM  file.   If  the
18       input  has one plane, or you choose just one plane of it, the output is
19       PBM.  Otherwise, the output is PGM.
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21       JBIG is a highly effective lossless compression algorithm for  bi-level
22       images  (one bit per pixel), which is particularly suitable for scanned
23       document pages.
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25       A JBIG encoded image can be stored in several  resolutions  in  one  or
26       several  BIEs.  All  resolution layers except the lowest one are stored
27       efficiently as differences to the next lower resolution layer.  You can
28       use  options -x and -y to stop the decompression at a specified maximal
29       output image size.  The input file can consist of several  concatenated
30       BIEs  which  contain different increasing resolution layers of the same
31       image.
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OPTIONS

35       -x number
36              Decode only up to the largest resolution layer  which  is  still
37              not  more  than number pixels wide.  If no such resolution layer
38              exists, then use the smallest one available.
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41       -y number
42              Decode only up to the largest resolution layer  which  is  still
43              not  more  than number pixels high.  If no such resolution layer
44              exists, then use the smallest one available.  You can  also  use
45              options  -x and -y together which selects the largest layer that
46              satisfies both limits.
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49       -b     Use binary values instead of Gray code words in order to  decode
50              pixel  values  from  multiple bitplanes.  This option has effect
51              only if the input has more  than  one  bitplane  and  you  don't
52              select  just  one of those bitplanes.  Note that the decoder has
53              to be used in the same mode as the encoder and cannot  determine
54              from the BIE, whether Gray or binary code words were used by the
55              encoder.
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58       -d     Diagnose a BIE.  With this option, jbigtopnm only prints a  sum‐
59              mary  of the header information found in the input file and then
60              exits.
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63       -p number
64              If the input contains multiple bitplanes, then extract only  the
65              specified  single plane as a PBM file.  The first plane has num‐
66              ber 0.
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STANDARDS

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

77       jbigtopnm  is  based  on  the  JBIG library by Markus Kuhn, part of his
78       JBIG-KIT package ⟨http://www.cl.cam.ac.uk/~mgk25/jbigkit/⟩ .  The  jbg‐
79       topbm program is part of the JBIG-KIT package.
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81       jbigtopnm is part of the Netpbm package of graphics tools.
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LICENSE

89       If  you  use  jbigtopnm, you are using various patents, particularly on
90       its arithmetic encoding method, and in all probability you do not  have
91       a license from the patent owners to do so.
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95netpbm documentation           19 November 2003       Jbigtopnm User Manual(0)