Improved Listless Zerotree Image Compression Algorithm and Application

The classic SPIHT algorithm need to maintain three lists to store temporarily the image´s zerotree structure and significance information, which represents a major drawback for hardware implementation because a large amount of memory is needed to maintain these lists. Besides, there is still some redundancy in the zerotree structure of SPIHT. Memory requirement of the algorithm is reduced significantly in LZC because of the replacement of lists by flag maps, but the performance of codec is also lowered. In this paper, a new listless zerotree image compression algorithm is presented. An improved zerotree structure and a new coding procedure are adopted, which improves the reconstructed image quality. Moreover, the lists in SPIHT are replaced by flag maps and lifting scheme is adopted to realize wavelet transform, which lowers the memory requirements and speeds up the coding process. The matching experiments of reconstructed standard stereo images demonstrate the feasibility and effectiveness of the proposed method.