基于仿射协变区域的抗几何攻击图像水印算法

Geometric Attacks Resistant Image Watermarking in Affine Covariant Regions

提出了一种基于仿射协变区域的抗几何攻击数字图像水印算法.首先利用仿射不变点检测算子提取图像特征点,并通过基于最小生成树聚类算法的选择策略获得一组稳定且彼此独立的仿射协变特征区域.然后基于特征区域,利用图像归一化和主梯度方向对齐得到具有缩放和旋转不变性的圆形区域.最后将水印在空域直接嵌入到圆形区域中.大量的实验结果表明本文方法是有效的,对常规图像处理、几何攻击以及组合攻击均具有较好的鲁棒性.

A robust image watermarking in affine covariant regions is proposed. First, the affine-invariant point detector is used to extract feature points of a given host image. A set of stable and non-overlapped affine covariant regions are then chosen via selection criterion based on the minimum spanning tree clustering algorithm. Secondly, image normalization and dominant gradient orientation alignment are performed on these feature regions to achieve scaling and rotation invariance. Finally, watermarks are directly embedded in these feature regions. Extensive experimental results demonstrate that the proposed scheme is robust against common image processing operations, geometric attacks, and combined attacks.