基于渐近优化检测器的数字水印最佳检测阈值的确定

Determination of digital watermarking optimal detection threshold based on asymptotically optimal detector

数字水印系统中检测阈值的大小会影响到检测器的检测效果。渐近优化检测器是一种采用Rao检验方式的盲水印检测算法,但其检测阈值是完全凭经验人为设定的,为了使渐近优化检测器阈值的确定客观与精确,利用最小差错概率准则对检测阈值进行了理论分析,并具体给出了一个水印检测系统错误率达到最小的最佳检测阈值的计算公式。实验结果表明,该方法能使水印检测系统的错误率在理论上达到最小,同时检测阈值的大小具有自适应性和客观性。

The magnitude of detection thresh will influence the effect of watermarking detector. The asymptotically optimal detector is a blind watermarking detection adopting Rao test, but its detection thresh is determined by experience. In order to make asymptotically optimal detection thresh more objective and accurate, the minimum error probability criterion was analyzed. The detection thresh based on asymptotically optimal detector was theoretically deduced to gain an expression of optimal detection thresh which made error rate of watermarking detection system lowest. Simulation results indicate that this method is adaptive and objective and can make error rate of watermarking detection system theoretically minimum.