Multiple description coding using pairwise correlating transforms

The objective of multiple description coding (MDC) is to encode a source in to multiple bitstreams supporting multiple quality levels of decoding. In t his paper, we only consider the two-description case, where the requirement is that a high-quality reconstruction should be decodable from the two bit streams together, while lower, but still acceptable, quality reconstruction s should be decodable from either of the two individual bitstreams. This pa per describes techniques for meeting MDC objectives in the framework of sta ndard transform-based image coding through the design of pairwise correlati ng transforms. The correlation introduced by the transform helps to reduce the distortion when only a single description is received, but it also incr eases the bit rate beyond that prescribed by the rate-distortion function o f the source. We analyze the relation between the redundancy (i.e., the ext ra bit rate) and the single description distortion using this transform-bas ed framework. We also describe an image coder that incorporates the pairwis e transform and show its redundancy-rate distortion performance for real im ages.