pgmtopbm - convert a PGM image to PBM
pgmtopbm
[
-floyd |
-fs |
-threshold |
-hilbert |
-dither8 |
-d8 |
-cluster3 |
-c3 |
-cluster4 |
-c4 |
-cluster8 |
-c8]
[
-value val]
[
-clump size]
[
-randomseed integer]
[
pgmfile]
This program is part of
Netpbm(1).
This program is almost entirely obsolete since Netpbm 10.23 (July 2004). Use
pamditherbw(1) to do what this program used to do.
pgmtopbm never was the simple converter it appeared to be. It was a
dithering program. Unfortunately, it didn't do the dithering properly because
it treated the PGM input samples as if they were directly proportional to
light intensity, but they are actually gamma-adjusted.
pamditherbw is backward compatible with
pgmtopbm except that it
- •
- does the correct gamma adjustments.
- •
- produces PAM output instead of PBM. (Modern Netpbm programs
that accept PBM input also accept PAM input, but if you need actual PBM,
you can use pamtopnm with pamditherbw).
So use the manual for pamditherbw for pgmtopbm, except ignore
anything that says it was added after Netpbm Release 10.23 and ignore any
options that are not shown in the synopsis above.
Although
pgmtopbm is mostly obsolete, the simple threshold method
(specified by
-threshold) is an exception. Unlike the other conversion
methods, gamma-adjustment is not an issue with simple thresholding and
pgmtopbm can produce PBM output directly. Note that even in this basic
mode of operation
pgmtopbm may produce output which is slightly
different from what
pamditherbw does because of differences in internal
calculation.
If you just want to convert a PGM image with maxval 1 to PBM, use
pamtopnm(1).
pamditherbw(1),
pamtopnm(1),
pbmtopgm(1),
pamthreshold(1),
pbmreduce(1),
pgm(1),
pbm(1)
Copyright (C) 1989 by Jef Poskanzer.
This manual page was generated by the Netpbm tool 'makeman' from HTML source.
The master documentation is at
- http://netpbm.sourceforge.net/doc/pgmtopbm.html