pgmenhance(1)                                       pgmenhance(1)

NAME
       pgmenhance - edge-enhance a portable graymap

SYNOPSIS
       pgmenhance [-N] [pgmfile]

DESCRIPTION
       Reads  a  portable  graymap as input.  Enhances the edges,
       and writes a portable graymap as output.

       The edge enhancing  technique  is  taken  from  Philip  R.
       Thompson's  "xim" program, which in turn took it from sec-
       tion 6 of "Digital Halftones  by  Dot  Diffusion",  D.  E.
       Knuth,  ACM Transaction on Graphics Vol. 6, No. 4, October
       1987, which in turn got it from two 1976 papers by  J.  F.
       Jarvis et. al.

OPTIONS
       The  optional -N flag should be a digit from 1 to 9.  1 is
       the lowest level of enhancement, 9  is  the  highest,  The
       default is 9.

SEE ALSO
       pgmedge(1), pgm(5), pbm(5)

AUTHOR
       Copyright (C) 1989 by Jef Poskanzer.

                         13 January 1989                        1