SKELETONIZATION VIA DISTANCE MAPS AND LEVEL SETS

The medial axis transform (MAT) of a shape, better known as its skelet on, is frequently used in shape analysis and related areas. In this pa per a new approach for determining the skeleton of an object is presen ted. The boundary is segmented at points of maximal positive curvature and a distance map from each of the segments is calculated. The skele ton is then located by applying simple rules to the zero sets of dista nce map differences. A framework is proposed for numerical approximati on of distance maps that is consistent with the continuous case and he nce does nor suffer from digitization bias due to metrication errors o f the implementation on the grid. Subpixel accuracy in distance map ca lculation is obtained by using gray-level information along the bounda ry of the shape in the numerical scheme. The accuracy of the resulting efficient skeletonization algorithm is demonstrated by several exampl es. (C) 1995 Academic Press, Inc.