# pgmenhance

Updated: 13 January 1989
Index

## 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, pgm, pbm

## AUTHOR

Copyright (C) 1989 by Jef Poskanzer.

## Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
SEE ALSO
AUTHOR