一种抗几何攻击的图像水印算法

几何攻击能有效破坏水印信号的同步,所以几何攻击一直制约着数字水印技术的实用性。本文分析了几何攻击破坏水印信号同步的原因,并基于图心与仿射变换的关系提出了一种新颖的抗几何攻击的水印检测算法。该算法不是采用传统的图像归一化技术,所以保证了水印图像的高透明性,即保证了嵌入水印后的图像的高质量。应用该算法能有效检测出遭受过平移、旋转与缩放等几何攻击以及它们的联合攻击后的水印。实验结果表明该算法对多种几何攻击都具有很高的鲁棒性。

AN IMAGE WATERMARKING ALGORITHM ROBUST TO GEOMETRIC ATTACKS

Geometric attacks can effectively destroy the watermark signal synchronization,it has been the practicality constraints of digital watermarking technique.In this paper we analyzethe real cause of geometric attacks underminingwatermark signal synchronization,and propose a novel image watermarking extracting algorithm based on therelationship between centroid and affine transform.The algorithm does not apply the traditional image normalizationtechnique,so it guarantees watermarkedimage high transparency,that is toensure high quality of watermarkedimage.The use of this algorithm can effectively extract the watermark from the watermarked images which have been suffered some geometric attacks such as rotation,scaling,translation,aspect ratio change and their joint attacks.The experimental results show that the algorithm on a variety of geometric attacks are highly robust.