基于Krawtchouk矩和Contourlet变换的多目的水印

Multipurpose Watermarking Algorithm Based on Krawtchouk Moment and Contourlet Transform

提出了一种基于Krawtchouk矩和Contourlet变换的多目的水印算法.首先对图像进行两级Contourlet分解,通过计算其低频分量的Krawtchouk低阶矩不变量来构建鲁棒水印,然后在剩下的带通分量中选择一个作为水印嵌入域并在其中嵌入半脆弱水印,给出了实验结果,并从水印的不可见性、抗攻击能力及篡改的定位能力三个方面进行了定量评测.实验结果表明,该算法具有很强的鲁棒性和较好的脆弱性,能同时有效地保护版权和认证图像.

A multipurpose watermarking scheme for digital image is proposed.After contourlet transform,the subband coefficients are extracted.Then the lower order Krawtchouk moments of the low frequency subbands coefficients are computed,and the watermark is composed of the mean of several functions of the moments.An embedded domain from other subbands is chosen,and the semifragile watermark is embedded in it.Quantitative evaluation of invisibleness,ability of resisting the attack and location ability of resisting the falsification of the watermark was made.The results demonstrate the effectiveness of our algorithm in terms of robustness and semifragility.