一种基于双重变换域的公钥水印方案

提出了一种基于双重变换域的公钥水印方案．针对WWW上的知识产权(IPR)保护，该方案引入了公开水印和私有水印，并根据小波系数特点以及树结构关系，利用主成份分析(PCA)将两种水印混合编码后加栽在同一幅图像中，不仅实现了水印的不可见性和高度鲁棒性．而且允许任何人验证IPR权威机构为图像生成的公开水印，同时保证作者能提取自己的私有水印作为版权证据，为数字产品版权保护开辟了一条新的思维途径．实验表明：使用该方法嵌入的数字水印对常规的图像处理方法具有较强的鲁棒性．

Public Key Method for Watermark Based on Dual-Transform Technique

A public key method for watermark based on dual transform technique is described in the paper. In order to meet the demands of intellectual property rights (IPR) protection on the world wide web ,both public watermark and private watermark are designed in this method. According to the characteristics and tree structure relations of the wavelet coefficients,the hybrid code of the two kinds of watermarks are embedded into the original image by combining principal component analysis (PCA) with wavelet transformation.The hidden datas are imperceptible and highly robust.Additionally,this method not only allows anyone to verify the public watermark which IPR authority designs but also guarantees that creator can extract his own private watermark as copyright evidence.,and so a new train of thought is therefore proposed for multimedia copyright protection.The experimental results show that the embedded watermarks are robust enough against the common image processing techniques.