Multidirectional curvilinear structures detection using steerable pyramid

The work described in this paper concerns directional structures detection for particular aspects of inspection, such as scratches and marbling defect detection in leather images, or for particular medical imaging problems, such as mammography analysis. Because of the very specific geometry of these structures, we apply a multiscale and orientation-shiftable method. Scratches and marbling have various shapes and sizes. In mammograms, stellate masses have an irregular appearance and are frequently surrounded by a radiating pattern of linear spicules. Multiscale approaches using oriented filters have proved to be efficient to detect both types of curvilinear patterns. The detection is based on steerable filters, which can be steered to any orientation fixed by the user, and are synthesized using a limited number of basic filters. These filters are used in a recursive multiscale transform: the steerable pyramid. Then, the curvilinear structures are extracted from the directional images at different scales. (C) 2004 SPIE and IST.