Macroblock-Level Mode Based Adaptive in-Band Motion Compensated Temporal Filtering

Abstract

This paper presents an adaptive in-band motion compensated temporal filtering (MCTF) scheme for 3-D wavelet based scalable video coding. The proposed scheme solves the motion mismatch problem when motion vectors from the LL subband are inaccurately applied to the highpass subbands in decoding high spatial resolution video. Specifically, we compare the macroblock residue energy in the highpass frames obtained by using motion vectors from both the LL and highpass subbands, and then adaptively transmit different sets of motion vectors based on whether mismatch has occurred in the highpass subbands. Macroblocks in the higher temporal levels favour the selection of highpass subbands' motion vectors because the motion estimation process becomes less accurate as temporal level increases. The modes information, which specifies whether the LL subband motion vectors or the highpass subbands' motion vectors are used by the current macroblock, is coded by run-length coding. Experimental results show that the proposed scheme improves both the visual quality and PSNR for high resolution decoding with comparison to other in-band MCTF schemes. Furthermore, our scheme requires only modifications when performing MCTF in the highpass subbands, thus, the original strength of in-band MCTF for decoding low spatial resolution video is well preserved.