基于IFS理论的数字水印算法  

A Digital Watermark Scheme Based on IFS Theory

作　　者：王兴元[1] 石其江[1] 孙天凯[1] 

机构地区：[1]大连理工大学电子与信息工程学院,大连116024

出　　处：《中国图象图形学报》2008年第3期419-427,共9页Journal of Image and Graphics

基　　金：国家自然科学基金项目(60573172);高等学校博士学科点专项科研基金项目(20070141014)

摘　　要：为了使数字水印算法具有更好的鲁棒性,首先阐述了迭代函数系(iterated function system,IFS)理论,并给出了构造IFS吸引子的随机迭代算法;然后从理论分析了IFS吸引子抗几何失真的特性,并提出了一种非对称数字水印算法;接着利用三点法将数字水印信息转化为IFS码,并由重构的分形水印图像与原始图像进行相关性处理得到索引集;最后版权者和第3信任方用私钥将索引集进行数字签名和加盖时间戳。水印检测时,只需利用第3信任方和版权者的公钥,而不需要原始图像参与。实验结果表明,该算法对噪声、滤波、压缩、旋转等图像处理方法具有较好的鲁棒性。In this paper, in order to obtain more robust digital watermark scheme, firstly the theory of iterated function system（IFS） and the stochastic algorithm by which IFS attractor is constructed are proposed. Secondly, by analyzing the robust character against geometric distortion of IFS attractor theoretically, a new scheme is provided,which is a asymmetric digital watermark one. Thlrdly,using tri-point method, the paper translates the information of digital watermarking into IFS code,and the indices set can be attained by reconstructing the image of fractal watermarking and manipulating the original image relatively. Finally the index set is signed and time-stamped by the owner and trusted third party＇s private keys. Using the owner and trusted third party＇s private keys ,the watermark can be detected without the original image. The experimental results show that the watermark scheme is robust against image manipulations, such as noise adding, filtering, compression and rotation.

关 键 词：数字水印 IFS吸引子 数字签名 时间戳 图像处理 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]