基于Radon变换不变矩的鲁棒性数字水印技术

Robust digital watermarking image method based on Radon invariant moments

现有的大多数数字水印算法在设计时过分地强调载体数据中嵌入水印以及在遭受几何攻击之后水印的不可感知性和鲁棒性,而对水印在检测时数字水印的虚警率和漏检率实验分析甚少。如果一个数字水印算法在水印检测时它的虚警率和漏检率很高,即使这种算法具有很好的鲁棒性那么也不能有效地解决版权保护,相反却会引入新的版权纠纷。针对以上提出的问题,提出一种基于Radon变换不变矩的抗几何攻击鲁棒性数字水印可以有效地减少水印的漏检和误检问题。本算法使用Radon变换构建矩不变量,首先使用小波变换的多尺度分析的特性,提取小波分解后的低频逼近子图;其次采用图像置乱的方法消除低频逼近子图像素之间的空间相关性,并通过零像素值模板背景图像代替图像尺度大小归一化;然后将置乱后的低频子图加载到零像素值模板背景图像上;最后使用Radon变换不变矩来设计水印和检测水印。经过仿真实验证明,该方法对于旋转,缩放,平移等攻击具有很好鲁棒性的同时,对于普通的加噪,滤波,JPEG压缩攻击也具有很好的鲁棒性,且具有极低误检率。

Most existing digital watermarking algorithms exceedingly focus on the imperceptibility and robustness of the watermarked image and geometric transform watermarked image.However,the analysis of false probability of watermarked image detection is insufficient.If a digital watermarking algorithm has a higher false probability in watermark detection,it can not solve copy-rights problem efficiently although this algorithm has a good robustness.On the contrary,it may cause a new copyright dissension.For above reasons,this paper proposes a digital watermarking image resisting to geometric attacks based on radon invariant moments which can decrease the false probability of watermarked image.This algorithm uses the radon transform to construct invariant moments.Firstly,the characteristic of wavelet transformation is used to extract low frequency image.Secondly,this paper makes use of image scrambling to eliminate the corelation among image pixels,and uses zero pixels value model background image to replace image scale normalization,and then the low frequency image has been scrambled to zero pixels value model background image.Finally,the radon invariant moments are used to design watermark and detect watermark.The experiments demonstrate the proposed method is more robust to RST transforms,also it is more robust to adding noise,filtering and JPEG compression attacks.So the proposed method is a simple,useful and credible algorithm.