Unequal loss protected multiple description subband coding
Jing Chen, Canhui Cai, S.K. Mitra · 2004
A new multiple description coding scheme with unequal loss protection is presented. In this approach, we code the hierarchical tree structure of the wavelet coefficients of the transformed image with an X-tree coder and code significant coefficients with scalar quantization, respectively. Since the hierarchical trees are comprised of the crucial information of the transformed image, zero maps, signs and the most significant bits of the significant coefficients, they are coded in both descriptions. The remaining parts of these significant coefficients are split into two indices by multiple description scalar quantizers, coded and sent to separate descriptions. Two descriptions are then transmitted over diverse channels. Because both descriptions include all critical information of the picture, the reconstructed image from any single channel has an acceptable fidelity. The proposed method yields a reconstructed image with a much higher quality if both channels are available. Simulation results have verified the performance of the proposed scheme.