Hillshading With Oriented Halftones

Patrick J. Kennelly* Assoc. Research Professor & GIS Manager Montana Tech of the University of Montana Montana Bureau of Mines and Geology 1300 W. Park Street Butte, MT 59701 Hillshading renders a surface with a three-dimensional appearance using shades of gray. Although shades appear as continuous tones, they must undergo a halftoning process for use with most computer output devices. This process generally uses one pattern of black and white pixels for each shade of gray, while attempting to make patterns associated with black and white pixels as difficult to detect as possible.