A hybrid M-channel filter bank and DCT framework for H.264/AVC intra coding

摘要

In H.264/AVC, discrete cosine transform (DCT) is performed on the residual blocks after prediction. However, the mismatch between variable block sizes and the fixed transform matrix not only degrades decorrelation performance but also causes severe blocky artifacts inside the blocks. In previous work, M-channel filter bank system (MCFBS) was proposed to overcome these defects. However, the increased percentage of encoding time by using MCFBS is very high, especially for intra coding. More seriously, the constructed M-channel filter bank with floating-point coefficients is an obstacle to hardware implementation. In this work, a hybrid M-channel Filter bank and DCT (HMD) framework is proposed for intra coding. Besides, the integer transform of a newly constructed M-channel filter bank is also implemented for HMD. Experimental results demonstrate that HMD can reduce 64-69% of the complexity of MCFBS with negligible quality degradation.