一种改善无损压缩性能的预处理及其理论分析

A preprocessing method for improving the lossless compression and its theoretical analysis

在 JPEG2000 无损编码方案中增加一步预处理而提出了一种新的编码算法。这种算法在编码端增加一项简单的预处理运算,在解码端增加了逆预处理运算。算法十分简单,在时间上没有明显增加,而在压缩比上有一定程度的提高。试验结果表明,采用这种编码算法时,压缩比可以提高 20%;理论分析也证实,只要能够保证减小图像的整体方差就能改善压缩比。该预处理也可应用于其它无损压缩算法。

A new coding algorithm is proposed by adding a preprocessing to JPEG2000 lossless coding scheme. A simple preprocessing operation will be added to encoder and a reverse preprocessing is added to decoder. The algorithm is very simple. The operation time will not be obviously added but the compression ratio has been improved to a certain degree. The test results show that when the coding algorithm is adopted, the compression ratio can be improved for 20%. The theoretical analysis also demonstrates that the compression ratio can be improved so long as the integral variance of image is reduced. The preprocessing can be also applied to other lossless compression algorithms.