An Adaptive Intra Refreshing Method for Improving Effects on Error Recovery in MPEG-4

In the adaptive intra refresh method adopted in MPEG-4, a case that errors occurring in transmission propagate frame to frame and also spread inside a frame is still observed. This paper proposes a modified method for performing the intra refresh adaptively. This method applies an intra-block encoding scheme to macro-blocks according to the number of pixels referred in the motion compensated predictive coding scheme, instead of applying it to moving macro-blocks just periodically in a fixed order inside the frame. Simulation results using test sequences demonstrate that this method reduces error propagation in shorter term than the conventional method, while causing less increase of the number of codes. The number of error spread pixels decreases by about 30% in the proposal method