中文摘要：

为了对数字媒体作品的版权信息进行有效的保护，在Chen和Chang提出的零水印版权认证系统方案的基础上，利用基于提升算法的Haar整数小波变换和带有膨胀操作的Sobel特征检测方法，对零水印签名和验证过程的特征提取方式进行了改进。通过适当选取阂值参数，对比三种算法在不同种类信号处理攻击下的性能，改进的零水印系统方案对于模糊、噪声、有损压缩、剪切、锐化、旋转和缩放等攻击模式具有良好的鲁棒性。仿真结果进一步验证了算法的有效性能。

英文摘要：

In order to protect the ownership of digital multimedia works, proposed an improved zero-watermark copyright authentication scheme that is based upon Chen＇ s and Chang＇ s algorithms. In proposed scheme, used Haar integer wavelet transform which was based on lifting scheme and Sobel detection with dilation manipulation to extract image feature matrix in signing and to perform verification procedure of the zero-watermark, when selected the threshold properly. Comparing performance against many kinds of signal processing attacks with the other two algorithms, it is concluded that the proposed scheme, which can resist some attacks such as blurring, noising, lossy compression, sharpening, rotation and scaling, has good performance of robustness, and it is further verified by some simulation experiments.