fstopgm

fstopgm - convert a Usenix FaceSaver(tm) file into a portable graymap

fstopgm [fsfile]

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 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.

pgmtofs(1), pgm(5), pgmnorm(1), pnmenlarge(1), pnmscale(1), pgmtopbm(1)

Copyright (C) 1989 by Jef Poskanzer.