fstopgm - convert a Usenix !FaceSaver?(tm) file into a portable graymap
Reads a Usenix !FaceSaver?(tm) file as input. 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
- 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
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.
pgmtofs(1), pgm(5), pgmnorm(1), pnmenlarge(1), pnmscale(1),
Copyright (C) 1989 by Jef Poskanzer.