In this paper, we propose a modification of the Shapiro’s Embedded Zerotree Wavelet (EZW) algorithm. Our approach, called
Modified EZW (MEZW), distributes entropy differently than Shapiro’s by using six instead of four symbols used in EZW and also
optimizes the coding by a binary grouping of elements before coding. This approach can produce results that are a significant
improvement on the PSNR and compression ratio obtained by Shapiro, without affecting the computing time. These results are
also comparable with those obtained using the SPIHT and SPECK algorithms.
Keywords Image compression - Shapiro’s EZW algorithm - MEZW - Entropy - Coding - PSNR - Compression ratio - SPIHT and SPECK algorithms