pgmtopbm - Man Page

convert a PGM image to PBM

Examples (TL;DR)



[-floyd | -fs | -threshold | -hilbert | -dither8 | -d8 | -cluster3 | -c3 | -cluster4 | -c4 | -cluster8 | -c8]

[-value val]

[-clump size]

[-randomseed integer]



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

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).

See Also

pamditherbw(1), pamtopnm(1), pbmtopgm(1), pamthreshold(1), pbmreduce(1), pgm(1), pbm(1)


Copyright (C) 1989 by Jef Poskanzer.

Document Source

This manual page was generated by the Netpbm tool 'makeman' from HTML source.  The master documentation is at

Referenced By


17 July 2020 netpbm documentation