Method and apparatus for encoding a contour of an object based on a

Abstract

A contour encoding apparatus encoding a contour of an object in a current frame based on a previous frame first generates a global motion vector between the current and the previous frames and calculates the number of contours in the previous frame. Then, the apparatus determines, for each of current contours, an optimum contour among the previous contours and detects a local motion vector between the optimum and the current contours. Once the global and the local motion vectors are determined, a predicted contour corresponding to each of the current contours is generated by shifting the optimum contour by the global and the local motion vectors. By using the predicted and the current contours, an error representing a difference therebetween is extracted. Subsequently, flag signals describing how close each of the previous contours is to a corresponding current contour are produced based on the number of the previous contours and contour encoding information corresponding to each of the current contours and sequences of the errors and the local motion vectors for the current frame are outputted based on the contour encoding information corresponding to each of the current contours. Finally, the flag signals and the sequences of the errors and the local motion vectors are multiplexed and then the multiplexed data is transmitted as an encoded contour data.