基于图像归一化的彩色图像空域零水印算法

为了有效实现对数字彩色图像的版权保护,本文提出了一种可有效抵抗几何攻击的数字图像空域零水印算法。首先利用基于矩的图像归一化技术将原始图像的绿色分量映射到几何不变空间内;然后以几何中心提取出归一化图像的重要区域;最后随机从重要区域提取特征像素与水印像素按位异或运算构造零水印。理论分析和实验结果表明,本文算法比以图像不变质心提取出归一化图像的重要区域的水印算法的性能更稳定,比基于离散小波同类零水印算法具有更强的抗剪切、几何变换、图像处理和常规信号处理攻击的能力。

A New Color Image Spatial Domain Zero-Watermarking Algorithm Based on Image Normalization

In order to achieve the copyright protection of digital color images,a geometrically robust image spatial domain zero-watermarking algorithm is proposed.Firstly,the green layer of the color image's geometrically invariant space is constructed by using the image normalization method.Then,the significant region is obtained from the normalized image by utilizing the geometric center.Finally,the zero-watermarking is constructed by performing the XOR(Exclusive OR) operation on the pixel of the watermark with another pixel randomly extracted from the significant region.The theoretical analysis and experimental results show that the algorithm's performance is more stable than the watermarking algorithm based on the significant region obtained from the normalized image by utilizing the invariant centroid.Compared with the same class zero watermarking algorithm based on digital wavelet transform(DWT),it has a stronger ability of anti-shearing,geometric distortions,image processing and signal processing attacks.