【摘要】 虽然分形图像压缩技术在高压缩比时具有高的重建图像质量,但是它编码过程耗时长导致了它难以在图像压缩领域广泛应用.为了减少寻找range块的最佳匹配domain块的时间,本文提出了基于方差剔除条件的分形编码方法,它利用均方根误差和方差关系的不等式,设置一个range块与domain块匹配搜索的提早结束条件来避免全搜索,从而减少编码过程的时间,实现加快编码速度的目的.计算机仿真显示,对5幅复杂性不同的测试图像,在影响解码图像主观质量很小的情况下,本文方案加快了基本分形编码算法的编码速度27倍.更多还原

【Abstract】 Although fractal image compression has high quality at high compression ratio, it needs a lot of encoding time so that it has not been widely applied as other coding schemes in the field of image compression. In this paper, with an inequality linking the root-mean-square and variance , a fast fractal image coding method based on variance kick-out condition is proposed to avoid the excessive search, in which the search process might be early terminated , and thus remaining domain blocks could be discarded, so its runtime is significantly shortened. Computer simulations on 5 test images with different complexities demonstrate that the proposed scheme could averagely achieve the speed-up of 27 times as the baseline fractal algorithm with full search, while it gives an insignificant degradation in the subjective quality of the decoded image .更多还原