Speed-Up of Encoder Optimization Step in Multiple Description Scalar Quantizer Design

The design of optimal multiple description scalar quantizers was pioneered by Vaishampayan with a generalization of Lloyd´s algorithm, which alternatively optimizes the decoder, respectively the encoder, while the other component is fixed. We propose an algorithm which speeds up the encoder optimization step from O(N ²) to O(N log N) time complexity, where N is the number of cells in the central partition.