Optimizing the MPEG-4 encoder-advanced diamond zonal search

Motion Estimation (ME) is an important part of the MPEG-4 encoder, due to its significant impact on the bitrate and the output quality of the encoded sequence. Unfortunately this feature occupies a significant part of the encoding time especially when using the straightforward Full Search (FS) algorithm. The Diamond Search (DS) was recently accepted as a fast motion estimation algorithm for the MPEG-4 VM. In this paper we propose a new algorithm named Advanced Diamond Zonal Search (ADZS), which is significantly faster than DS (in terms of number of checking points and total encoding time) and gives similar, if not better, quality (in terms of PSNR) of the output sequence. This is more obvious in the high bit rate cases. Our experiments verify the superiority of the proposed algorithm.