NAME

       pgmtopbm - convert a PGM image to PBM

SYNOPSIS

       pgmtopbm

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

       [-value val]

       [-clump size]

       [-randomseed integer]

       [pgmfile]

DESCRIPTION

       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).

SEE ALSO

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

AUTHOR

       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

              http://netpbm.sourceforge.net/doc/pgmtopbm.html