基于混沌置乱和混合变换域的扩频水印方案  

Spread Spectrum Watermarking Scheme Based on Chaos Scramble and Hybrid Transform Domains

作　　者：许文丽[1] 苏万力[1] 李磊[1] 王育民[1] 

机构地区：[1]西安电子科技大学ISN国家重点实验室,西安710071

出　　处：《计算机科学》2007年第7期248-250,F0004,共4页Computer Science

基　　金："十一五"军事通信技术预研项目(110010203)

摘　　要：本文基于混沌置乱和DWT和DCT混合变换域提出了一种扩频数字水印方案,首先对原始水印信息进行混沌置乱预处理,然后应用扩频技术,选取m-序列作为扩频码,对置乱预处理后的水印信息进行扩频,产生扩频水印信息,在充分考虑人眼视觉特性的基础上确定扩频水印在DWT和DCT混合变换域的嵌入位置和强度,扩频增益因子的选取大小取决于所选用的DWT和DCT混合变换域系数的个数以及水印大小。实验结果表明,应用文中提出的基于混沌置乱和混合变换域的扩频水印方案,不但水印的安全性有了很大程度提高,而且对剪切、旋转等各种几何失真攻击和常见的信号处理如噪音、JPEG压缩和滤波攻击具有很强的鲁棒性,即使嵌有水印的图像遭受攻击后受损较严重,水印信息还是能够完好地提取出来。In this paper, a robust spread spectrum digital watermarking algorithm based on chaos scramble and hybrid transform domains is proposed. Firstly, in order to enhance the security of the watermarking, the original meaningful binary image digital watermarking is scrambled by using Arnold transform. Then the scrambled watermarking is spread by using spread spectrum technology. Taking into account the characteristics of human visual system （HVS）, the positions and strengths of embedding into coefficients of the hybrid DWT and DCT domain are obtained. Selecting spread spectrum gain factor is determined by chosen coefficients of hybrid DWT and DCT domain and watermarking size. The experimental results show that the presented chaos scramble and hybrid transform based spread spectrum dig- ital watermarking algorithm is more secure and robust against geometric distortions （such as cropping, rotating and so on） and general image processing operations （such as adding Gaussian noise, JPEG glossy compression, filters）. Though the quality of the watermarked image is seriously degraded because of the attacks , the watermarking can be extracted very well.

关 键 词：数字水印 混沌置乱 扩频水印 离散小波变换(DWT) 离散余弦变换(DCT) 

分 类 号：TP37[自动化与计算机技术—计算机系统结构]