This program is part of Netpbm.
ppmrelief reads a PPM image as input, does a Laplacian relief filter,
and writes a PPM image as output.
The Laplacian relief filter is described in 'Beyond Photography' by
Holzmann, equation 3.19. It's a sort of edge-detection.
pgmbentley, pgmoil, ppm
Copyright (C) 1990 by Wilson Bent (firstname.lastname@example.org)
netpbm documentation 11 January 1991 Ppmrelief User Manual(0)