基于方向剖分的小波域分形图象压缩  

The Scheme of Wavelet-fractal Coding Based on Oriented Partition

作　　者：周艳[1] 吴敏金[2] 

机构地区：[1]温州师范学院电教科,温州325003 [2]华东师范大学教育信息技术系,上海200062

出　　处：《华东师范大学学报（自然科学版）》2002年第3期20-27,共8页Journal of East China Normal University(Natural Science)

摘　　要：该文提出一种新的分形和小波混合编码方法 -基于方向剖分的小波域分形图象压缩方法 :在将图象分解到小波域后 ,对各子图象 ,根据其所占能量的大小和所代表的方向纹理信息 ,采用不同大小、形状与类别的定义域块和值域块进行分形编码。经实验证明 ,这种基于方向剖分的小波域分形编码方法 ,在保证一定的还原图象质量的前提下 ,可以大大地提高了分形编码的速度 ,如果结合多层小波分解的分形压缩编码的预测法和零树法 ,还能进一步提高压缩率 。A scheme of fractal coding based on oriented partition of the coefficients of the wavelet transform is presented here. This new method involves two steps. First, the original image is decomposed into subimages by the wavelet transform. Then, every subimage isencoded using the fractal coding method with range and domain blocks of different size and shape according to the energy and orientation information of the subimage. Experimental results show that our method can greatly reduce encoding time compared tothe standard fractal image coding method, whereas the PSNR of decoded images is only reduced slightly. If fractal predictive image coding scheme and zerotrees of wavelet coefficients are combined, can be obtained higher compression rate. This will improve the practical use of fractal image coding.

关 键 词：小波域分形图象压缩 分形图象编码 小波变换 方向剖分 小波分解 压缩率 

分 类 号：TN919.81[电子电信—通信与信息系统]