Pbmtog3 User Manual(1) General Commands Manual Pbmtog3 User Manual(1)
NAME
pbmtog3 - convert a PBM image into a Group 3 MH fax file
SYNOPSIS
pbmtog3 [-reversebits] [-nofixedwidth] [-align8|-align16] [pbmfile]
DESCRIPTION
This program is part of Netpbm(1).
pbmtog3 reads a PBM image as input and produces a Group 3 MH fax file as
output.
You can also generate a TIFF file that uses the same encoding inside,
with pamtotiff.
There is no program in Netpbm that generates other fax formats, such as
MR and MMR, but pamtotiff can generate TIFF files that use those encod-
ings.
OPTIONS
In addition to the options common to all programs based on libnetpbm
(most notably -quiet, see ]8;;index.html#commonoptions\ Common Options]8;;\ ), pbmtog3 recognizes the fol-
lowing command line options:
-reversebits
This option causes the output to have the bits in every byte re-
versed so the least significant bit becomes the most significant
bit. Some fax modems expect bits in reverse order, and this com-
pensates for that. If you get a whole bunch of "bad code word"
messages when you try to read the G3 file (e.g. with g3topbm),
try using this option. Note that the output is not G3 when you
use this option.
-nofixedwidth
Most fax machines expect the image to be 1728 columns wide, so
pbmtog3 cuts the output to this width by default. If you want to
keep the width of the original image, use this option.
This option was new in Netpbm 10.6 (July 2002). Before that,
pbmtog3 always kept the width of the original image.
-align8
-align16
These options say to align output rows to 8-bit or 16-bit bound-
aries, respectively, by adding padding bits in front of EOL codes
Without these options, pbmtog3 adds no padding and rows may begin
and ends anywhere within a byte.
You cannot specify both.
These options were new in Netpbm 10.79 (June 2017).
SEE ALSO
g3topbm(1), pamtotiff(1), pbm(1), fax formats(1)
HISTORY
Before Netpbm 10.79 (June 2017), there was a different program by the
same name in Netpbm, which was written by by Paul Haeberli <paul@man-
ray.sgi.com> in 1989 and then modified extensively by others.
Akira Urushibata <afu@wta.att.ne.jp> wrote the current version, with an
entirely different algorithm, in April 2017 and contributed his work to
the public domain.
The current program is backward compatible with the pre-10.79 version.
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/pbmtog3.html
netpbm documentation 20 April 2017 Pbmtog3 User Manual(1)
Generated by dwww version 1.16 on Tue Dec 16 04:54:04 CET 2025.