Fast index assignment for robust multiple description coding

Based on multiple description coding, the robust multiple description scalar quantizer (RMDSQ) was introduced to combat both packet losses and noisy channels over heterogeneous networks. In the RMDSQ, the description with bit errors is utilized to achieve graceful performance degradation. However, because of high computational complexity of the index assignment (IA) by using exhaustive search and the genetic algorithm, it is not practical in applications where the training time is of primary concern. In this paper, we propose a novel IA algorithm with low computational complexity to achieve a balanced RMDSQ, in which parity bits are added to realize robustness against bit errors. The algorithm proposed can be implemented "on-the-fly" by using logic circuits, and easily applied in bitplane-based image compression. Experimental results show that the proposed algorithm outperforms existing algorithms in the sense of both spreads and computational complexity.