Zonal MPEG-2

This paper presents a simple but effective approach to improve the performance of MPEG-2. This study is motivated by (i) the energy compaction property in DCT and (ii) the property of human visual system. Both (i) and (ii) indicate that low-frequency coefficients are more important than others in the DCT transformed blocks. Moreover, the quantized transformed coefficients in high-frequency region are zero or approximate zero in general. Those coefficients contribute nothing or little to PSNR and may waste some bit rate in the MPEG-2. Therefore, the zonal coding scheme is applied to the MPEG-2 where some high-frequency coefficients are discarded. The proposed approach is called zonal MPEG-2 which is totally compatible with the traditional MPEG-2. The zonal MPEG-2 is verified by examples and shown to be able to significantly reduce the bit rate with acceptable perceptual quality degradation when compared with the traditional MPEG-2.