pgmtopbm man page

pgmtopbm — convert a PGM image to PBM



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

[-value val]

[-clump size]



This program is obsolete since Netpbm 10.23 (July 2004).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 pamtopbm 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.

If you just want to convert a PGM image with maxval 1 to PBM, use pamtopnm(1)

Document Source

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



Explore man page connections for pgmtopbm(1).