应用数字全息解决数字水印技术中采用log-polar变换后水印的提取问题  

Applying digital holography to solve the problems of watermarking extraction by log-polar transform

作　　者：周皓[1] 顾济华[1] 陈刘[1] 

机构地区：[1]教育部现代光学技术重点实验室

出　　处：《激光杂志》2007年第6期39-40,共2页Laser Journal

摘　　要：log-polar(对数-极坐标)变换是目前数字水印在抵抗几何攻击时常常采用的手段,但是此种算法存在的主要问题是采用不同的坐标变换带来的数字图像信息的丢失,导致水印可提取性下降或者原图质量的下降。本文应用了数字全息的方法,解决了以上的两个由于log- polaf变换带来的主要问题。仿真实验证明,该方法解决了数字水印图像信息的丢失,大大提高了数字水印的可提取性。Log - polar transform is a common method in the digital watermarkings to resist geometric attacks. But the major problem is the loss of the information of the digital images by different coordinate＇s transform. It will lead to the difficulty of the watermarking extraction or the decrease of the original images＇ quality. This paper suggests a method applying digital holography which will solve the former 2 problems of the log - polar transform. Experiment results verify that this method has solved the problem of the loss of the digital images＇ information . It improves the possibility of the embedding watermarkings＇ extraction greatly.

关 键 词：信息光学 数字全息水印 log—polar变换 RST 

分 类 号：O436.1[机械工程—光学工程] TN919[理学—光学]