摘要： 针对一类灰度水印系统设计理论存在的不足，给出指导该类灰度水印算法设计的一系列理论结果，包括嵌入强度、鲁棒性、不可见性三者之间定量关系的建立，提出水印算法不可见性和鲁棒性的折中方案，采用已有的算法对理论结果进行验证，结果表明，得出的理论结果对该类水印算法的设计具有较大的指导意义。

关键词: 灰度水印, 酉变换, 特征信号, 峰值信噪比

Abstract: Aiming at the defects of design theory of a kind of gray-scale watermarking system, this paper gives a series of theory results to guide this kind of gray-scale watermarking algorithms, including quantitative descriptions among the embedding strength, the robustness and the invisibility. The compromise between invisibility and the robustness is presented. The results are verified by the existing algorithms. Experimental results show that these results are of great guiding significance to gray-scale watermark algorithms design.

Key words: gray-scale watermark, unitary transformation, characteristic signal, Peak Signal-to-Noise Ratio(PSNR)

中图分类号: 

• TP391