【摘要】 从数字水印需要传递水印及原始媒体两个信息出发研究了数字水印中各个角色的攻防关系。利用了数字水印的不可感知性这一要求,提出了图像空间,感知空间及检测空间的概念,并在这3个空间上定义了图像空间阈值,感知空间阈值和检测空间阈值3个阈值。分析了数字水印系统中发送者、攻击者及接收者在上述3个阈值之间的攻防关系,结果表明,数字水印与大多数信息隐藏技术一样,其实是一个寻找隐蔽信道的问题。在此基础上给出了具体例证,得出了一些有益于数字水印嵌入、检测及攻击的指导性思想。更多还原

【Abstract】 The communication model of digital watermarking is investigated from the view of the imperceptivity of digital watermarking. The concepts of image space, perceptual space and watermark space is proposed and the image threshold, perceptual threshold and watermark threshold are defined on the three spaces. The relationship among the sender, the attacker and the receiver is analyzed. The results show that the key of digital watermarking is to find a covert channel, which is similar to the steganography. An information_theoretic model of digital watermarking is presented and one can use it to describe other information hiding technology, such as steganography. The model is analyzed and an example is given. Some constructive ideal for the sender, the attacker and the receiver is given.更多还原