Adaptive Chain Coding for Arbitrary Curves

N.L. Chang1 S.R. Kulkarni1 J. Koplowitz2 1Department of Electrical Engineering Princeton University, Princeton, NJ 08544 [email protected], [email protected] (609) 258-6727 2Department of Electrical and Computer Engineering Clarkson University, Potsdam, NY 13676 [email protected] (315) 268-6545 ABSTRACT An adaptive chain coding algorithm based on using multiple templates is developed. The algorithm di erentially encodes a curve using a directional template whose angle is dynamically scaled to accomodate a variety of curvature properties. A second template is occasionally used for reorientation if abrupt changes occur in the properties of the underlying curve. By exploiting the piecewise regularity of most curves, our technique provides substantially more accurate and e cient encodings compared with standard chain coding algorithms.