Adaptive joint rate allocation and quantization in subband signal coding

We propose an elegant yet efficient adaptive subband coding scheme in which the rate allocation and structures of the quantizers are jointly optimized based on the time-varying rate-distortion characteristics of the input signals. By employing the tree-structured vector quantizers and the generalized BFOS pruning algorithm, the operations of the rate allocation and quantization are elegantly combined, whereby the adaptation is both convenient and optimal. The results on video coding have shown that the adaptive scheme can achieve substantial performance improvement over the non-adaptive scheme.