摘要
本文提出了一种DCT域的闭环数字水印技术,水印的嵌入是一个闭环过程。水印嵌入的初始强度由视觉系统结合JPEG量化表确定,并根据性能分析的结果不断调整水印的嵌入,如果性能分析结果不能满足某种检测要求或者水印的嵌入已经影响了图像的显示质量,相应调整水印嵌入的强度,以实现水印的最佳嵌入。本文证明了所提出的闭环水印过程具有收敛性,还对检测过程中的似然函数的分布规律进行了分析,得到正确检测概率和错误检测概率的表达式,可作为闭环系统的判决条件。实验结果证明这种闭环水印技术比传统DCT域的水印技术性能好。
A new closed loop digital watermarking in DCT domain is proposed in this paper. The embedding process is modified continuously according to the results of the performance analysis of watermarking. If the watermarking can not meet the requirements or the embedded watermark renders visual artifact, the embedded intensity of watermark is modified so as to obtain optimal embedding effect. The convergence of the closed loop techniques is proved. In the performance analysis, the distribution of likelihood function is analyzed, and the mean and the variance of two hypothesis tests and their relationship are deduced. The probabilities of false alarm and detection are also given which are used as the performance measures for the closed loop system. Experimental results show that this closed loop watermarking technique performs better than traditional watermarking.
出处
《通信学报》
EI
CSCD
北大核心
2002年第4期1-10,共10页
Journal on Communications
基金
国家自然科学基金重大资助项目(69896246)
关键词
DCT域
闭环数字水印技术
保密通信
DCT domain
closed loop digital watermarking
performance analysis
