A Medial Axis Transformation for Grayscale Pictures

摘要

Blum's medial axis transformation (MAT) for binary pictures yields medial axis points that lie midway between opposite borders of a region, or along angle bisectors. This note discusses a generalization of the MAT in which a score is computed for each point P of a grayscale picture based on the gradient magnitudes at pairs of points that have P as their midpoint. These scores are high at points that lie midway between pairs of antiparallel edges, or along angle bisectors, so that they define a MAT-like skeleton, which we may call the GRADMAT. However, this skeleton is rather sensitive to the presence of noise edges or to irregularities in the region edges. (Author)