基于尺度不变特征点的抗几何攻击水印算法

利用基于尺度空间理论的特征点检测方法，检测出的特征点不但在大尺度缩放变换下重复率高，而且每个特征点的特征尺度随图像缩放尺度等比例变化。以特征尺度及特征点相对位置作为参考，生成一种几何变换自适应图形作为水印嵌入的区域。随着特征点相对位置的变化，自适应图形会产生相应变化，达到抗几何攻击的目的。实验表明，该算法能有效抵抗各种几何攻击，具有较好的性能。

Anti-geometric Attack Watermark Algorithm Based on Scale Invariant Feature Points

The paper proposes a feature point detection method which based on scale-space theory. The feature points can resist large-scale transformations, and the characteristic scale of every point changes in proportion with the picture’s scaling. Referring to feature scale and feature points’ relative position, the self-spanning patterns are generated as the watermark embedding area. The figure can change along with the transformation of points’ relative position, and then geometric robust watermark can obtain. Experiment result shows that the proposed method is robust against common geometric distortions.