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  section  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                            pgmenhance(1)