Post-processing for decoding without update step in motion-compensated lifted wavelet video coding

Motion-compensated temporal filtering is an open-loop coding technique, which generally employs a motion-compensated update step. Although the update step is essential at the encoder for good rate-distortion efficiency, it might be skipped at the decoder for benefits like lower complexity and lower playout delay. Previous investigations showed that skipping the update step at the decoder results in some quality degradation at high rates. In this paper we analyze how this degradation arises and also propose a simple method to reduce this degradation. The proposed solution can also be implemented as a post-processing procedure after conventional decoding without the update step. Experimental results show that the degradation in quality is reduced by half. For our t+2D wavelet coder, this gives a gain of approximately 1.0 - 1.5 dB at high bit-rates.