结合小波变换的零搜索分形图象编码

为提高分形图象编码的质量，缩短编码时间，针对Monro在文献1]中提出的零搜索分形图象编码方法，其恢复图象在存在的块效应的问题，提出了一种结合小波变换的多项式近似快速分形图象编码方法，该方法是利用各频带间能量分布不均衡的特性，构造一种结合小波分解的分形图象编码算法，首先对图象进行塔式离散正交小波变换，然后再对小波系数进行分形编码，实验结果表明，用该算法对图象进行编码，不仅使恢复图象的质量得到了较大的提高，而且编码时间仅用1．48s。

Zero-Searching Fractal Image Coding Based on Wavelet Transform

In order to improve quality of fractal image coding and reduce coding time, a fast polynomial fractal image coding method based on wavelet decomposition is presented in this papre. Jacquin's fractal image coding method needs searchign for the optimum domain block in the image. It must take so long time to do this searching work. This character is a fatal flaw of the method which confine this method in using. Monro's fractal image coding method doesn't meed searching for the optimum domain block, so his fractal image coding is very rapid and simple in reference. His coding method is zero searching fractal coding method and its coding time is very short. But his reconstructed image has blocking effect. In this paper. in order to solve this question, a new fractal image coding based on discrete wavelet transformation is presented. The new method also doesn't need searching for the optimum domain block, so its coding time is very short. This algorithm utilizes the character of wavelet analysis which is unbalanced distributions of energy in subbands among wavelet trasform image. The algorithm based on discrete wavelet transformation is:First, the image is decomposed into different channels by discrete wavelet transformation. Second, wavelet coefficients are encoded by fractal image coding method. Simulation shows that the quality of the reconstructed image is improved greatly and coding time is only 1.48 seconds.