SUB-PIXEL DISTANCE MAPS AND WEIGHTED DISTANCE TRANSFORMS

A new framework for computing the Euclidean distance and weighted dist ance from the boundary of a given digitized shape is presented. The di stance is calculated with sub-pixel accuracy. The algorithm is based o n an equal distance contour evolution process. The moving contour is e mbedded as a level set in a time varying function of higher dimension. This representation of the evolving contour makes possible the use of an accurate and stable numerical scheme, due to Osher and Sethian [22 ]. The relation between the classical shape from shading problem and t he weighted distance transform is presented, as well as an algorithm t hat calculates the geodesic distance transform on surfaces.