usage: clump inimg.bw outimg.bw diameter [threshold]
clump removes all pixels whose intensities are greater than threshold and are not at the centre of a diameter X diameter square of pixels whose intensities are also greater than threshold. In the case of an even diameter, all four possible squares are tried. Pixels that are removed are replaced with pixels of threshold intensity value. threshold defaults to 0 if not specified on the command line.
clump can be used as a preprocessing step before colourise.
Author: Matthew Belmonte