Tchebichef矩在图像数字水印技术中的应用

Application of Tchebichef moment in image watermarking techniques

提出了一种利用原始图像的Tchebichef矩来增加水印顽健性的方法,即利用原始图像的一个或多个Tchebichef矩的值来估计水印图像所经过的几何变换的参数以及图像增强等图像处理操作的参数,并将这一过程作为水印检测的预处理过程。实验中将多种不同的水印信息在不同的图像处理域(包括DWT、DCT、FFT以及空间域等)实现水印信息的嵌入。为了检测这种估计算法的顽健性,本文实验中的几何攻击是由Stirmark产生的。计算机模拟实验证明这种估计方法简单,估计精度很高,增加了图像水印技术对几何攻击的顽健性,而且可在任何处理域中实现,具有很好的实用价值。

A new way to enhance the robustness of watermarking is proposed by estimating the geometric distortions and enhancing parameters of corrupted watermarked image using Tchebichef moments of original image. Different watermarks are embedded into different original images in different domains including DWT, DCT, FFT and spatial domain. The geometric distortions are produced by Strimark. The computer simulation results show that the proposed method has a good robustness to Strimark and can be used in any domain. This method can be used as preprocess step of watermark detection and it is very useful to improve the processing robustness against geometric attacks of watermarking techniques.