I. Introduction
H.264/A VC [1] is a new video standard of the Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG for high quality video coding. Compared to the previous video coding standards (e.g., MPEG2, H.263, and MPEG4), H.264/AVC achieves higher compression ratios under the same video quality [2], [3]. The performance improvement comes mainly from the new coding techniques adopted in H.264/AVC (e.g., flexible block size and quarter-pixel inter prediction, spatial intra prediction, and context-based adaptive binary arithmetic coding, etc). Among the new coding tools, the intra prediction improves the coding performance when the inter prediction fails to find a good match, which is used to reduce the residues in compression of still images as well.