Lossless Image Coding Using Embedded Zerotree Wavelet Framework: Part I. EZW Coding

Research advances in wavelet theory and subband coding have created a surge of interest in wavelet based applications during the past decade. Image coding (or compression) is an important application that has benefited significantly from the wavelet theory. Lossless image coding using the embedded zerotree wavelet (EZW) is the main focus of this work and also in the sequel to this work. The EZW lossless coding framework consists of three stages: (i) a reversible wavelet transform, (ii) an EZW data structure to order the coefficients and (iii) an arithmetic coding using context modeling. In this work, we discuss the experiments conducted in the first and second stage of the framework using the set partitioning based EZW coding to optimize the compression efficiency.