Optimal DCT coefficient adjustment applied to MPEG-2 SNR scalability

SNR scalability and data partitioning have both been proposed by MPEG-2 as a means of guaranteeing minimum quality in the presence of information loss for such applications as ATM networks. Whilst SNR scalability can guarantee a superior base quality to data partitioning it is disadvantaged by a 5-15% increase in total bit-rate. In this paper we consider two methods that use optimal DCT coefficient adjustment in order to reduce bit-rate overheads. By comparing with single layer and data partitioning, we are able to demonstrate significant bit-rate reductions, to the extent that an optimised SNR scalable coder is able to outperform data partitioning, not just in terms of base picture quality, but also in terms of bandwidth utilisation