Rate-distortion optimized intra update for error resilience in MPEG-4 video coding

Motion compensation is a powerful method to compress a video sequence. However, once an error occurs, the error propagates through the frames. Recently, the intra update method was proposed to stop the error propagation at the cost of the compression efficiency. This paper proposes an intra update method based on rate-distortion optimization in error prone environments. The rate and the distortion are estimated using the Lagrangian optimization method to simultaneously select the coding mode and the quantization step size. The proposed method is applied to moving picture experts group (MPEG)-4 codec, and experimental results show that it is robuster to the packet loss than the conventional ones. (C) 2004 Wiley Periodicals, Inc.