Alignment-Based Recognition of Shape Outlines

We present a 2D shape recognition and classification method based on matching shape outlines. The correspondence between outlines (curves) is based on a notion of an alignment curve and on a measure of similarity between the intrinsic properties of the curve, namely, length and curvature, and is found by an efficient dynamic-programming method. The correspondence is used to find a similarity measure which is used in a recognition system. We explore the strengths and weaknesses of the outline-based representation by examining the effectiveness of the recognition system on a variety of examples.