In this paper

a new shape coding algorithm called curvature scale space based shape coding(CSS) is proposed. For dealing with video image

we regard a shape as a set of points that are parameterized by arc length. Then

the evolution of curve at different resolution levels in Gaussian scale space is achieved by convoluting the curve with Gaussian kernel. By calculating the curvature

the feature-points including significant information of shape contour can be found. But for shape coding

this shape representation will not very efficient when the shape consists of arcs. So

the CSS is modified

then extract the feature points of shape using the modified CSS algorithm. The octants algorithm is modified and encode the feature points by using adaptive arithmetic code algorithm. Simulation results show that our proposed algorithm has higher compress ratio

better subjective quality compared with other results from the CAE in MPEG-4.