Highly efficient contour-based predictive shape coding

A new scheme for contour-based predictive shape coding is proposed aiming to acquire high coding efficiency, where the temporal correlations among object contours are effectively exploited. For a given binary shape image, the object contours are firstly extracted and thinned to be perfect single-pixel width followed by chain-based representation. Then a chain-based motion estimation and compensation technique is developed to remove temporal correlations among object contours to reduce the data to be encoded. Finally, by further exploiting the spatial correlations within chain links, a novel method is introduced to efficiently encode the residuals together with the motion displacements. Experiments are conducted and the results show that the proposed scheme is considerably more efficient than the existing techniques.