中文摘要：

水印检测是数字水印技术的一个关键步骤，但是目前所提出的绝大多数水印检测算法既不具备赖以支撑的理论基础，其检测性能也不是优化的．利用数字水印的不可感知特性，应用弱信号检测理论进行水印检测的研究．首先从图像小波变换系数的统计特性出发，利用广义高斯分布（GGD）来建立小波细节子带系数的统计分布模型；然后针对水印嵌入强度未知的情况，将水印检测问题转化为非高斯噪声中具有未知参数的确定性信号的检测，在弱信号条件下提出一种离散小波变换（DWT）域图像水印的优化盲检测算法．检测性能分析表明，该检测算法能够实现恒虚警率水印检测．实验结果验证了检测性能理论分析的有效性和实际性能的优越性．

英文摘要：

The performance of a watermarking scheme relies heavily on the design of the detector. However, most of watermark detection algorithms in the literature are neither with strong theoretical grounds, nor are they optimum. Proposed in this paper is a new discrete wavelet transform （DWT） domain watermark detection scheme, with the theory of weak signal detection in non-Gaussian noise as its theoretical grounds. Special attention is paid to the case where embedding strength parameter of the watermark signal is not known at the detection stage. First, generalized Gaussian distribution （GGD） is chosen to statistically model the wavelet coefficients of the detailed sub-bands data. Then, the model of deterministic signal detection with unknown parameters is utilized to formulate the watermark detection. As a result, an asymptotically optimal detector is constructed. The performance analysis of the new detector shows that it can achieve the constant false alarm rate property. The theoretical analysis is validated through experimental results. And the superiority of the novel detector over conventional detection methods is also confirmed.