图像拟仿射变换的DWT水印算法  

Digital watermarking algorithm based on DWT and quasi affine transformation

作　　者：林晓圆[1] 赵健[1] 谢瑜[1] 余秋菊[1] 

机构地区：[1]西北大学信息科学与技术学院,西安710127

出　　处：《计算机工程与应用》2011年第12期84-86,89,共4页Computer Engineering and Applications

基　　金：中国博士后科学基金(No.20060401007);陕西省自然科学基础研究项目(No.2007F38)

摘　　要：提出一种图像拟仿射变换的DWT水印算法。该算法对水印图像的预处理采用有限整数域上的拟仿射变换,拟仿射变换有较好的置乱效果及较大的置乱周期,从图像信息加密的安全性角度来看,它优于Arnold等常见的几何置乱变换,利用混沌序列提取原始图像的若干块组成子图像,并对子图像进行三次小波变换,将加密图像嵌入到子图像中,并将子图像还原到原始图像的相应位置。实现了水印的透明性和鲁棒性。仿真实验结果表明,算法对常见的图像攻击具有较强的鲁棒性和稳健性。It presented an digital watermarking algorithm based on DWT and quasi affine transformation.The algorithm uses quasi affine transformation to encrypt the watermark image in a limited integer field.Because quasi affine transformation has a good effect of the charateristics of scrambling and a longer period of scrambling.It is more secure than the common transformation,like Arnold and other geometric transformations.It extracts a number of blocks from the original image using chaotic sequence, and forms a new sub-image using those blocks,then makes the sub-image go to three wavelet transformations. The encrypted watermarking image is embedded into the sub-image, then the blocks of the sub-image are put into the origi- nal position in the original image.Experimental results show that this algorithm is robust and stable to common digital image processing operations.

关 键 词：拟仿射变换 离散小波变换 混沌序列 数字水印 

分 类 号：TP309[自动化与计算机技术—计算机系统结构] TP391[自动化与计算机技术—计算机科学与技术]