中文摘要：

水印检测错误会严重损害水印系统的可信度。该文提出基于双谱和能量检测的双通道检测来实现最优盲水印检测器的设计，并给出了一种在小波域中的具体实现。传统检测方法检测概率会随着信噪比的下降而急剧下降。双通道检测时信噪比很小时只要有足够大的双谱信息，即可得到较高的检测概率。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。实验过程中攻击由通用水印测试软件-Stirmark产生，实验数据证明所设计的最优盲检测器对Stirmark提供的各种攻击（如剪切、JPEG压缩、删行／列、旋转、尺度变换、随机几何攻击等）具有很好的鲁棒性。实验结果说明这种最优检测器的性能优越于现有的水印检测器。

英文摘要：

The detection errors undermine the credibility of a watermarking system. An optimum image blind watermark detector is designed in this paper in discrete wavelet domain, which adopts a dual channel detection using bispectrum detection and energy detection. Even with small signal noise ration, the detector can still get a high detection probability with enough bispectum information. When the bispectrum is small, this dual channel detection will become a likelihood detection system, and it is still an optimum detection system. Experimental results demonstrate that the proposed optimum watermarking detector is robust with respect to attacks produced by the popular watermark test software - Stirmark, such as cropping, JPEG compression, rotation, scaling, random geometrid distortion. The experimental results also show that this optimum image blind watermark detector has superior advantages than the exist watermark detectors.