pbmtopgm(12 Dec 1990) pbmtopgm(12 Dec 1990)
NAMEpbmtopgm - convert portable bitmap to portable graymap by
averaging areas
SYNOPSISpbmtopgm <width> <height> [pbmfile]
DESCRIPTION
Reads a portable bitmap as input. Outputs a portable
graymap created by averaging the number of pixels within a
sample area of width by height around each point. Pbmtopgm
is similar to a special case of ppmconvol. A ppmsmooth
step may be needed after pbmtopgm.
Pbmtopgm has the effect of anti-aliasing bitmaps which
contain distinct line features.
SEE ALSOpbm(5)AUTHOR
Copyright (C) 1990 by Angus Duggan Copyright (C) 1989 by
Jef Poskanzer.
Permission to use, copy, modify, and distribute this soft-
ware and its documentation for any purpose and without fee
is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation. This software is provided "as is" without
express or implied warranty.
NOTES
Pbmtopgm works best with odd sample width and heights.
1