B-SPLINE CONTOUR REPRESENTATION AND SYMMETRY DETECTION

The detection of edges is only one of many steps in the understanding of images. Further processing necessarily involves grouping operations between contours. We present a representation of edge contours by app roximating B-splines and show that such a representation facilitates t he extraction of symmetries between contours. Our representation is ri ch, compact, stable, and does not critically depend on feature extract ion. We turn our attention to the detection of three types of symmetri es: skew symmetries and parallel symmetries, which have proven to be o f great importance in inferring shape from contour, and smooth local s ymmetries, which have been used for planar shape description. We show that our representation facilitates the computation of these symmetrie s.