Geometrically robust image watermarking by sector-shaped partitioning of geometric-invariant regions.
Geometrically robust image watermarking by sector-shaped partitioning of geometric-invariant regions.
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DOI：
10.1364/oe.17.021819
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发表时间：
2009-11
期刊：
影响因子：
3.8
通讯作者：
Huawei Tian;Yao Zhao;R. Ni;Gang Cao
中科院分区：
文献类型：
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作者：
Huawei Tian;Yao Zhao;R. Ni;Gang Cao
在基于特征的几何鲁棒水印系统中，检测能够经受各种图像处理操作的几何不变区域是一项具有挑战性的任务。本文采用了一种鲁棒性更强的多尺度曲率积角点检测器（MSCP）来提取显著特征，取代了常用的Harris检测器或Mexican hat小波方法。基于这些特征，找到圆盘状的女孩，这包括三个步骤。首先，提取鲁棒边缘轮廓；然后，利用MSCP对女孩中心进行检测。第三步，进行特征尺度选择，计算各区域红外辐射半径；设计了一种新的扇区分割方法，利用最重要角（MIC）将一个GIR分割成多个扇区盘。然后利用量化指数调制（QIM）将水印信息逐位嵌入到每个扇区中。该方法对几何变换具有不变性，对几何攻击具有较强的鲁棒性。实验结果表明，该方法对常见的图像处理攻击、仿射变换、裁剪和随机弯曲攻击（RBA）具有较好的鲁棒性。
In a feature-based geometrically robust watermarking system, it is a challenging task to detect geometric-invariant regions (GIRs) which can survive a broad range of image processing operations. Instead of commonly used Harris detector or Mexican hat wavelet method, a more robust corner detector named multi-scale curvature product (MSCP) is adopted to extract salient features in this paper. Based on such features, disk-like GIRs are found, which consists of three steps. First, robust edge contours are extracted. Then, MSCP is utilized to detect the centers for GIRs. Third, the characteristic scale selection is performed to calculate the radius of each GIR. A novel sector-shaped partitioning method for the GIRs is designed, which can divide a GIR into several sector discs with the help of the most important corner (MIC). The watermark message is then embedded bit by bit in each sector by using Quantization Index Modulation (QIM). The GIRs and the divided sector discs are invariant to geometric transforms, so the watermarking method inherently has high robustness against geometric attacks. Experimental results show that the scheme has a better robustness against various image processing operations including common processing attacks, affine transforms, cropping, and random bending attack (RBA) than the previous approaches.