Jbigtopnm User Manual(1) General Commands Manual Jbigtopnm User Manual(1)
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 dou-
ble 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 stan-
dard input, decompresses it, and outputs a PBM or PGM file. If the in-
put 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-hy-
phen 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 se-
lect 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 sum-
mary 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 num-
ber 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 jbg-
topbm 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
netpbm documentation 28 July 2020 Jbigtopnm User Manual(1)
Generated by dwww version 1.15 on Sat Jun 29 02:04:31 CEST 2024.