①Institute of Information Science and Technology, Huaqiao University, Quanzhou 362021, China; ②School of Electronic Information Engineering, Tianjin University, Tianjin 300072, China
Abstract：A new Multiple Description Coding (MDC) scheme, X-tree based unequal protected MDC subband coding is proposed in this paper. The information of the wavelet transformed image is decomposed into two parts, the structure information and residues of significant coefficients. The structure information, including positions, signs and bit lengths of significant coefficients, is crucial and should be duplicated into both descriptions. The residues are mapped into couples of indices by a multiple description scalar quantizers, and sent to separate descriptions. Two descriptions are dispatched from different channels. Because every description includes all critical information of the picture, the reconstructed image from any single channel can have acceptable fidelity. The reconstructed image is of much better quality if both channels are available. Simulation results have verified the performance of the proposed algorithm.
2005, Vol. 27 
