ppmrelief - run a Laplacian relief filter on a portable pixmap
ppmrelief [ppmfile]
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.
pgmbentley(1), pgmoil(1), ppm(5)
Copyright (C) 1990 by Wilson Bent (whb AT hoh-2 DOT att DOT com)