A method for representing shape based on an equivalence relation on polygons

摘要

It is proved that there is a correspondence between deformations of polygons and a grammar. This gives rise to an O(n logn) algorithm to match regions whose connectivity has been changed, based on boundary contours. This has application to problems in handwriting recognition. It is then shown that deformations of polygons can be decomposed into canonical types. This gives rise to new types of features, to measure symmetry, handedness, rigidity, bending and stretching.