fstopgm (1)
convert a Usenix FaceSaver(tm) file into a portable graymap
SYNOPSIS
DESCRIPTION
Reads a Usenix FaceSaver(tm) file as input.
FaceSaver
Produces a portable graymap as output.
FaceSaver(tm) files sometimes have rectangular pixels.
While
fstopgm
won't re-scale them into square pixels for you,
it will give you the precise
pnmscale
command that will do the job.
Because of this, reading a FaceSaver(tm) image is a two-step process.
First you do:
fstopgm > /dev/null
This will tell you whether you need to use
pnmscale.
Then use one of the following pipelines:
fstopgm | pgmnorm
fstopgm | pnmscale -whatever | pgmnorm
To go to PBM, you want something more like one of these:
fstopgm | pnmenlarge 3 | pgmnorm | pgmtopbm
fstopgm | pnmenlarge 3 | pnmscale <whatever> | pgmnorm | pgmtopbm
You want to enlarge when going to a bitmap because otherwise you lose
information; but enlarging by more than 3 does not look good.
FaceSaver is a registered trademark of Metron Computerware Ltd. of
Oakland, CA.
SEE ALSO
AUTHOR
Copyright (C) 1989 by Jef Poskanzer.
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