Watermarking algorithm resist local nonlinear geometric attacks based on reference points extraction
基于形殊点抗局部非线性几何攻击水印算法*

In order to improve the robustness of watermark algorithm resist nonlinear geometric attacks,this paper proposed an image watermark algorithm based on reference points extraction(RPE).This approach extracted the picture edge by Canny firstly.Second,blocked the picture edge and calculated the RPE coordinates of block image.Finally,obtained the copyright information by calculating user keys and the watermark.The results obtained from performance analysis show that the algorithm can reduce the computational complexity in a large scale,it’s sensitive to user keys and robust to nonlinear geometric attacks.