When the bispectrum is small, this dual channel detection will become a likelihood detection system, and it is still an optimum detection system.

• 即使双谱信息很小时双通道检测系统退化为似然比检测系统，仍是最优的。检测器检测到指定的水印后利用独立分量分析技术进行水印盲恢复。