基于新型四叉树分割的快速分形图像编码

Fast Fractal Image Encoding Based on Novel Quadtree Partition

针对现有的基于四叉树的分形编码算法比较耗时的问题,提出了一种基于新型四叉树分割的快速分形编码方法。首先根据人眼视觉系统(HVS)特性分割出子块,再将各不同尺寸子块所对应的父块库中的父块按标准差排序。对于每一子块,在对应的父块库中寻找其在标准差意义下的最近邻父块,然后在该父块的邻域内进一步搜索最佳匹配父块,同时引进误差阈值来控制子块的搜索过程。实验结果证明,该算法的编码速度大大提高。

In order to solve the problem of time consuming in the encoding process of the existing fractal image compression method based on quadtree partition, a fast method based on novel quadtree partition is presented. The image is divided into child blocks according to the feature of HVS. The codebook is ordered by their roots mean square error. For each child block, the nearest neighbor is found in the sense of root mean square error in the ordered codebook. Then searching for the best parent block in the vicinity of the nearest neighbor. At the same time, an error threshold is used to control the searching process. The experimental results demonstrate that the proposed algorithm is much faster.