一种改进的LZC图像编码算法

An Improved LZC Image Compression Algorithm

提出了一种改进的 L ZC(listless zerotree coding)图像编码算法 ,该算法不仅继承了原有 L ZC算法不使用链表、易于硬件实现的优点 ,而且针对原始算法子带扫描顺序不尽合理、递归结构算法复杂度较高等缺点 ,通过改变空间子带的编码顺序 ,将块的概念引入编码过程在改进算法中完全采用顺序结构等措施进一步提高了原有算法的工作效率、降低了 L ZC算法的复杂度。实验结果表明 ,该算法是一种高效的图像编码算法 ,其不仅具有良好的视觉效果、无方块效应 ,而且在相同压缩比情况下 ,该算法的图像重构质量和 PSNR均明显优于原始的 L

In this paper,an improved listless zerotree coding(LZC)Algorithm is presented. LZC is an image coding algorithm that uses no list during encoding and decoding, permitting the omission of the lists requirement in Said and Pearlman's set partitioning in hierarchical trees(SPIHT) algorithm. Consequently, the memory requirement in a VLSI implementation is reduced significantly. The improved LZC algorithm not only includes the advantage of original LZC in which lists do not be used and that is implemented easily in hardware, but also improves the work efficiency of LZC and reduces the complexity of LZC by changing the coding order of spatial subbands, using the concept of block in the coding process and adopting entirely the ordinal structure in the improved LZC image compression algorithm aiming at the disadvantages of original LZC algorithm such as the unreasonable scanning order and the complicating recursive structure. Finally, the experimental results show that our proposed coding method not only has the properties of good vision effect, non square effect and no edge oscillation, but also performs better than that of original LZC algorithm in the aspects of the quality of image reconstruction and PSNR under the basis of the same ratio of compression.