Variable decay rate histogram modelling for image compression

Abstract

Several methods exist for adaptation to non-stationary statistics in histogram modelling. Among the techniques that perform local adaptation by decaying histogram counts, we show that fixed decay rate schemes are sub-optimal. We use an order-0 model and an arithmetic coder to demonstrate that improved performance can be obtained by using a variable decay rate scheme that uses the derivative of the per-symbol codelength sequence to control the rate of decay.