A bit allocation scheme for a class of embedded wavelet video encoders

In this paper, we investigate bit allocation strategies for a class of embedded wavelet video encoders. They take advantage of the precise control that such coders have over the bit-rate of each frame. We first show that a piecewise-linear model suits the rate distortion characteristics of these encoders better than an exponential model, specially in low bit-rate applications. Then, we use an effective iterative procedure for dealing with the problem of frame dependency which yields improved rate distortion results. Two types of embedded wavelet coders, using scalar and vector quantization, are tested. The results are encouraging, showing that the adoption of an adequate rate-control strategy can improve both objective and subjective quality of video sequences encoded using such embedded wavelet video encoders. 2003 Elsevier Science (USA). All rights reserved.