Use of phase and certainty information in automatic detection of stellate patterns in mammograms

Detection of stellate patterns is a very important step in computer-aided detection schemes designed for mammography. We introduce a new way of finding these regions based on the use of quadrature filters. The method allows extraction of a certainty measure for each orientation estimate. This makes the method of finding the areas the spicules seem to emanate from more robust than simply basing it on the orientation estimates themselves. The local phase extracted from the filter outputs allows us to discriminate between orientation estimates from edges and dark lines from those generated by bright line structures, i.e. spicules. This makes the method more specific. We also show how the method can be modified for finding non-spiculated masses in digitized mammograms.