# info > g3topbm

[g3topbm(1)](https://www.chedong.com/phpMan.php/man/g3topbm/1/markdown)                  General Commands Manual                 [g3topbm(1)](https://www.chedong.com/phpMan.php/man/g3topbm/1/markdown)

## NAME
       g3topbm - convert a Group 3 fax file into a portable bitmap

## SYNOPSIS
       g3topbm [-kludge] [-reversebits] [-stretch] [g3file]

## DESCRIPTION
       Reads  a Group 3 fax file as input.  Produces a portable bitmap as out-
       put.

## OPTIONS
### -kludge
              Tells g3topbm to ignore the first few lines of the  file;  some-
              times fax files have some junk at the beginning.

### -reversebits
              Tells g3topbm to interpret bits least-significant first, instead
              of the default  most-significant  first.   Apparently  some  fax
              modems do it one way and others do it the other way.  If you get
              a whole bunch of "bad code word" messages, try using this flag.

### -stretch
              Tells g3topbm to stretch the  image  vertically  by  duplicating
              each row.  This is for the low-quality transmission mode.

       All flags can be abbreviated to their shortest unique prefix.

## REFERENCES
       The standard for Group 3 fax is defined in CCITT Recommendation T.4.

## BUGS
       Probably.

## SEE ALSO
       [pbmtog3(1)](https://www.chedong.com/phpMan.php/man/pbmtog3/1/markdown), [pbm(5)](https://www.chedong.com/phpMan.php/man/pbm/5/markdown)

## AUTHOR
       Copyright (C) 1989 by Paul Haeberli <<paul@manray.sgi.com>>.

                                02 October 1989                     [g3topbm(1)](https://www.chedong.com/phpMan.php/man/g3topbm/1/markdown)