分形用于图像压缩编码,分形编码非常费时，大部分时间浪费在给每个range块寻找合适的domain块，但如果减少搜索domain块的范围，编码速度将有很大提高。所以编码时用快限制分形编码,把图像分成4小块，每块中的range块只在这块中寻找domain块。-for fractal image compression coding, fractal coding is very time-consuming, most of the time wasted in each range block to find a suitable domain block, But if the search domain blocks to reduce the scope of coding speed will be greatly improved. So fast coding using fractal coding restrictions, the image is divided into four small pieces. every piece of the range block only find in this domain block.