NAME
    ppmrelief - run a Laplacian relief filter on a portable pixmap

SYNOPSIS
    ppmrelief [ppmfile]

DESCRIPTION
    Reads a portable pixmap as input. Does a Laplacian relief filter, and
    writes a portable pixmap as output.

    The Laplacian relief filter is described  in "Beyond Photography" by
    Holzmann, equation 3.19.  It's a sort of edge-detection.

SEE ALSO
   pgmbentley(1), pgmoil(1), ppm(5)

AUTHOR
    Copyright (C) 1990 by Wilson Bent (whb@hoh-2.att.com)