New padding algorithm for object-based coding

The boundary macroblock padding is one key technology of MPEG-4 codes. In MPEG-4, the repetitive padding algorithm does not make use of the trend of pixel value variation often near object boundaries in padding the exterior pixels of reference video object. In this paper, in order to improve performance of MPEG-4 coder, a linear padding for MPEG-4 motion estimation is proposed to reduce prediction errors and improve compression efficiency. In our test, the different video rate distortion curves verify that the proposed algorithm get the higher PSNR (0.4~2.5 dB) than the repetitive padding scheme does at different bit rate.