Delta codes for line drawings

A new class of chain codes for line drawings, named delta codes is introduced. Two specific types of fixed angle delta codes and ring delta codes are described. The area-of-error distortion and rate are calculated for two types of delta codes applied to straight and slowly curving lines, and it is shown that the delta outperforms other chain codes with the same set of link types. For rapidly curving lines, however, the delta codes introduce curvature overload distortion analogous to the slope overload distortion of traditional delta modulation for waveforms