Image watermarking algorithm against geometrical attacks inContourlet domain based on chaos
基于混沌的Contourlet域抗几何攻击图像水印算法

In order to improve the robustness against geometrical attacks and self-adaptability, this paper proposed an adaptive image watermarking algorithm in Contourlet domain based on chaos. Firstly, it applied a Contourlet transform to the cover image, and divided the low frequency sub-band into many blocks which were decomposed with singular value decompositionSVD. Secondly, it adaptively embedded the watermark information with chaotic encryption into the largest singular value of every block based on human visual system HVS. Finally, it extracted the feature points by the improved Harris-Laplace operator. During detection, restored the attacked imageby using feature points of it and those of the watermarked image. Experimental results show the proposed algorithm is robust to common image processing and geometric attacks such as JPEG compression, filtering, noise addition, rotation, scaling and translation.