在电子商务中利用数字水印实现数字图像产品的版权保护与跟踪

提出了一个基于小波变换的数字水印嵌入算法，将YIQ色彩空间的Y分量进行1，2，…，M级小波变换，提取出各级小波变换后近似图像的鲁棒系数构造水印，使构造的水印可包含RGB三个通道的特征信息。并根据小波零树结构的原理，将消费者指定的授权信息嵌入到M级小波变换后HL、LH子带的重要系数中，利用密钥保护与代理中心CA实现版权保护与跟踪，保护版权人与消费者的合法权益。实验证明，所提出的解决方案计算简单，安全性高．检测时不需要原始图像，很容易应用于电子商务中实现数字图像产品的版权保护与跟踪。

Digital Watermarking for Protecting and Tracking Copyrights in E-commerce

In current E-commerce, digital images can be easily copied and redistributed through the Internet. It's hard for digital images' producers and customers to protect their rights and interests. In this paper, an embedding algorithm is proposed for digital watermarking that can be used to protect and track copyrights. The algorithm is based on M-level wavelet transformation on the Y component of YIQ color space. From the approximate image after each wavelet transformation, the robust coefficients are extracted to build the watermarking. Therefore, the watermarking contains the characteristic information for all three RGB channels. According to the principle of wavelet zero-tree, the copyright information is embedded into the important coefficients of the HL and LH sub-bands, which are obtained after the M-level wavelet transformation. Copyright protection and tracking is achieved by employing secret keys and center agents. The original image is not required for checking the watermarking. Numerical experiments show that the algorithm's computation is simple and easy to realize. The algorithm can be easily implemented to protect and track the copyrights of digital image products in E-commerce.