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 encodings.

OPTIONS

       In addition to the options common to all programs based on libnetpbm (most notably -quiet,
       see
        Common  Options  ⟨index.html#commonoptions⟩  ),  pbmtog3 recognizes the following command
       line options:

       -reversebits
              This option causes the output to have the bits in every byte reversed so the  least
              significant  bit  becomes the most significant bit.  Some fax modems expect bits in
              reverse order, and this compensates 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 boundaries, 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@manray.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