<title>Motion-compensated adaptive interframe/intraframe prediction</title>

Abstract

Motion-compensated (MC) interframe prediction which has been used widely in low bit-rate television coding is an efficient method to reduce the temporal redundancy in a sequence of television signals. However, if there is a violent or complicated motion in the scene such as in the broadcast television, the performance of MC interframe prediction will degenerate seriously while the intraframe prediction is better. It is obvious that an adaptive prediction scheme will provide a lower and more stable transmission rate than that obtained by simple MC interframe prediction or intraframe prediction. In this paper, a motion-compensated adaptive inter/intra frame prediction scheme based on the block-based motion estimation algorithm we proposed earlier [11] is presented. Adaptivity is achieved block-wise by comparing prediction errors of MC interframe predictor and intraframe predictor, one of the predictors which gives the smaller error is chosen as the actual predictor. To further compress transmission bit-rate, a variable length encoding is designed to encode the prediction errors and the motion information according to their actual distributions. Simulation results have shown that this adaptive prediction scheme is very efficient for different kinds of pictures containing slow to very violent motion, and a'high compression rate can be archived with very good picture quality.