US Patent 7137098 Pattern component analysis and manipulation

A method for determining component patterns of a raw substrate map. A subset of substrate patterns is selected from a set of substrate patterns, and combined into a composite substrate map. The substrate patterns are weighted. The composite substrate map is compared to the raw substrate map, and a degree of correlation between the composite substrate map and the raw substrate map is determined. The steps are iteratively repeated until the degree of correlation is at least a desired degree, and the weighted subset of substrate patterns is output as the component patterns of the raw substrate map.