Piecewise linear tree-structured models for lossless image compression

Abstract

This paper presents a probabilistic model for use in lossless image compressors. For each pixel the model provides a conditional distribution, which in the most simple case is a discretized gaussian. The mean and variance of this gaussian are determined by using that pixel's neighbors to search a tree to find an autoregressive model, which is then applied to those same neighbors. Finally, arithmetic coding transmits the pixel. This paper also shows how to design this tree and find the distribution parameters associated with each leaf.