Enhanced transform domain intra prediction for MPEG-2 to H.264/AVC transcoding

In this paper, we proposed an enhanced transform-domain intra prediction method for H.264/AVC. In the proposed scheme, H.264/AVC intra prediction can be described by generalized linear operation after defining both H-filter and V-filter. Since intra prediction operation can be decomposed into some sparse matrices, we can reduce computational complexity for intra prediction. Our scheme can reduce the number of multiplication and addition operations more than Chen´s by 22.4% and 21.6%, respectively, in each 4times4 block. Furthermore, we show that matrix multiplication can be simply processed using a look-up table which consists of 9 types of 4times4 constant matrices corresponding to 9 prediction modes in H.264. Consequently, we can insist that the proposed scheme in this paper can be used for fast transform domain intra prediction in the area of transcoding MPEG-2 streams into H.264/AVC streams.