Multiple Description Transform Coding: A New Design Approach

Multiple-description coding (MDC) is an effective technique to support error-prone transmission in the scenario of multiple channels. Typically, an MDC is designed in the DCT domain where a pair-wise correlating transform (PCT) or some generalized version is further applied to some DCT coefficients of each image block. Although these correlating transforms offer a freedom of compromising the overall coding quality and the redundancy, none of them can be made optimal after taking into consideration the quantization characteristics. In this paper, we present a new design approach in which we will do a novel grouping of all DCT coefficients (not necessarily pair-wise) such that the distortion measured on some specified pixels within each image block is minimized. An interesting property of this new MDC design is that, when all descriptions are received, it provides a coding quality that becomes higher than the target quality set in the corresponding single-description coding (SDC) design.