Abstract
A simple but efficient technique for encoding object contour is presented. It is based on the chain coding representation and utilizes the benefit of differential chain coding (DCC) and entropy coding. DCC let the occurrences of symbols skewed. And the entropy coding let the frequently used symbols correspond to the short codes. This thesis proposes a simple DCC-based method to adaptively trace the contour direction locally and effectively select the code symbol accordingly. The method really alters the distribution of symbol occurrences to the extreme case, thus the gain of entropy code becomes significant. We conducted several experiments to compare with DCC with entropy coding and MPEG-4 shape coder. The experimental results show that this simple method is constantly better than DCC and comparable with the MPEG-4 shape code.