基于DCT变换的快速分形编码方法

本文提出了一种基于DCT变换加速相似块匹配的分形编码方法.通过图像块与相似块在DCT变换域少数低频系数的比较,来确定匹配的相似块.并根据DCT变换的性质,方便的确定对比度因子和亮度偏移量.并采用将图像块与相似块的DCT变换系数预制成查找表的方法减少重复运算.结果表明,编码时间大幅度减少,而PSNR只是略有下降.

A Fast Fractal Image Coding Method Based on the DCT Transform

This paper presents a fractal image coding method based on the DCT transform that speeds up the matching procedure in the sets of domain blocks.This method compares the few low frequency DCT transform coefficients of the range blocks and domain blocks to find out the matched domain block.In accordance with the properties of the DCT transform,it calculates the contrast scaling and luminance shift conveniently.At the same time,it stores the DCT transform coefficients of the range blocks and domain blocks into a lookup table to reduce the redundancy operations.The result shows that the coding time is reduced evidently,while PSNR is only reduced very little.