摘要
将多级离散小波变换的"多级"思想引入到离散余弦变换中,并对多级离散余弦变换的特性进行了分析,在此基础上提出了一种基于多级离散余弦变换的数字水印算法,该算法从多级离散余弦变换系数中选择适当的位置嵌入水印信息.实验结果表明文中算法的鲁棒性优于常规基于离散余弦变换的数字水印算法,并且它的实时性不受多级变换的影响.此外,该文对多级离散余弦变换中变换系数和变换级数的选择进行了研究,实验结果表明合理选择变换系数进行二级变换可以获得最佳性能.
The ＇Multiple-level＇ idea is introduced from Discrete Wavelet Transform to Discrete Cosine Transform, and the properties of multiple-level Discrete Cosine Transform are analyzed. A digital watermarking algorithm is proposed based on multiple-level Discrete Cosine Transform. In the proposed algorithm, the watermark information is embedded in the selected coefficients of multiple-level Discrete Cosine Transform. Experimental studies show that the proposed algorithm has better robustness compared with common digital watermarking algorithms based on Discrete Cosine Transform, and its real-time property is not affected by the multiple-level transform. Besides, the methods of choosing transform coefficients and transform levels are studied, and experimental results show that the best performance can be achieved by reasonably choosing transform coefficients for the two-level transform.
出处
《计算机学报》
EI
CSCD
北大核心
2009年第5期1055-1061,共7页
Chinese Journal of Computers
基金
国家"八六三"高技术研究发展计划项目基金(2003AA144080)
国家自然科学基金(60772155)
北京市自然科学基金(4082029)
中国博士后科学基金(20080440553)资助~~
关键词
数字水印
多级变换
离散余弦变换
鲁棒性
抖动调制
digital watermark
multiple-level transform
discrete cosine transform
robustness
dither modulation
