g32pbm - convert a Group 3 fax file into a portable bitmap
SYNOPSIS
g32pbm [ g3file ]
DESCRIPTION
Reads a Group 3 fax file (raw or digifax) as input. If no filename is
given, stdin is used.
Produces a portable bitmap as output.
OPTIONS
-r
Tells
g32pbm to interpret bits least-significant
first, instead of the default most-significant first ("-reversebits").
Some fax modems do it one way and others do it the other way. If you get
a whole bunch of "invalid code" messages (nearly one per line), try using
this flag.
-s
Double each horizontal row of the fax file in the pbm file ("-stretch)".
You can use this to adjust the aspect ratio of a "normal resolution" fax
file to match that of a "fine resolution" fax file. This might not seem
like it belongs here, but it's
much faster than using pnmscale|pgmtopbm later.
-s is activated automatically if the file is specified on the command
line and its name starts with "fn..." (fax/normal).
-l(aserjet)
Instead of a portable bitmap (PBM), output HP laserjet files, suitable for
direct printing on a HP laserjet or desjket.
-d <dpi>
Scale output to <dpi> dots per inch before printing. Normal FAX resolution
is 204x196 dpi (fine mode), or 204x98 dpi (normal mode). In LaerJet mode,
only the values 75, 150 and 300 are allowed for <dpi>.
-t
turn image by 90 degrees clockwise. Multiple -t commands increase angle,
that is, -t -t will turn it upside down, and so on.
-?
Print a short command syntax.
REFERENCES
The standard for Group 3 fax is defined in CCITT Recommendation T.4.
BUGS
g32pbm could be smarter about the image width, at the moment, the maximum width
is 1728 pixels, and the maximum height is 4300 lines. Everything bigger is
just cut off.
Only 'raw' pbm files are created.
Scaling is too slow.
Turning is too slow (and not yet fully implemented either).
g32pbm is Copyright (C) 1993 by Gert Doering, <gert@greenie.muc.de>. It is
similar to the
g3topbm program in Jef Poskanzers
pbmplus package, but it's a complete re-write. No code is copied.