为了使数字水印能更有效鲁棒地抗几何攻击，以图像归一化为基础，提出了一种可有效抵抗几何攻击的数字图像水印方案。该方案首先利用基于矩的图像归一化技术将原始载体映射到几何不变空间内；然后结合不变质心理论提取出归一化图像的重要区域；最后根据人眼视觉特性及小波系数相关性，利用自适应量化调制策略将水印信息嵌入到归一化图像的重要区域内。仿真实验结果表明，该图像水印方案不仅具有良好的透明性，而且具有较强的抵抗常规信号处理及几何攻击的能力。

In this paper, a geometrically robust image watermarking algorithm based on significant region of normalized image is proposed. The geometrically invariant space is firstly constructed by using image normalization method. Then the significant region is obtained from the normalized image by utilizing the invariant centroid theory. The digital watermark is embedded into the significant region by quantizing the magnitudes of the selected wavelet coefficients. Experimental results show that the proposed scheme is not only invisible and robust against common signals processing, but also robust against the geometric distortion.