In this paper, an enhanced version of Embedded zerotree wavelet (EZW) image coding algorithm is proposed, referred to as EZW-SC. By exploiting a new principle that relies on a subband classification concept, the enhanced algorithm allows the prediction of insignificant subbands at early passes, along with the use of an improved significance map. This reduces the redundancy of zerotree symbols, speeds up the coding process and improves the coding of significant coefficients. In fact, the EZW-SC algorithm scans only significant subbands and significantly improves the lossy compression performance with the conventional EZW. Moreover, new EZW-based schemes are presented to perform colour image coding by taking advantage of the interdependency of the colour components. Experimental results show clear superiority of the proposed algorithms over the conventional EZW as well as other related EZW schemes at various bit rates in both greyscale and colour image compression.

本文提出了一种改进的嵌入式零树小波（EZW）图像编码算法，称为EZW-SC。通过利用依赖于子带分类概念的新原理，增强算法允许在早期通过时预测无关紧要的子带，并使用改进的重要性图。这减少了零树符号的冗余，加快了编码过程并改善了重要系数的编码。实际上，EZW-SC算法仅扫描重要的子带，并显着提高了常规EZW的有损压缩性能。此外，提出了新的基于EZW的方案，以通过利用颜色分量的相互依赖性来执行彩色图像编码。