自嵌入双功能图像水印算法  

A Self-embedding Image Watermarking Scheme with Dual Purpose

作　　者：叶天语[1] 

机构地区：[1]浙江工商大学信息与电子工程学院,杭州310018

出　　处：《光子学报》2012年第7期859-867,共9页Acta Photonica Sinica

基　　金：浙江省教育厅项目(No.Y201017916)资助

摘　　要：利用自嵌入技术提出一种同时实现版权保护和内容认证的双功能图像水印算法.在嵌入端,首先将原始图像划分成互不重叠的子块,将各子块每个像素的最低m位置0,然后将最低m位置0后的子块进行奇异值分解,通过提取奇异值范数的最高位奇偶性产生原始鲁棒特征水印,然后再将原始鲁棒特征水印嵌入各子块每个像素的最低m位得到含水印图像.检测端从攻击的含水印图像提取鲁棒特征水印的过程与嵌入端产生原始鲁棒特征水印的过程类似,并且通过计算提取的鲁棒特征水印与原始鲁棒特征水印之间的归一化相关度进行版权鉴别,通过判断提取的鲁棒特征水印与攻击图像各子块每个像素的最低m位的一致性实现篡改检测进行内容认证.理论分析和实验结果都表明算法具有非常好的不可见性.实验结果还表明,算法不仅在抵抗添加噪音、剪切、JPEG压缩、平滑、重采样和几何攻击如随机删除行、向右偏移列、向下偏移行表现出很强的鲁棒性,而且能够精确定位出篡改位置和区分篡改类型.因此,算法具有版权保护和内容认证双重功能.An image watermarking scheme with dual purpose is proposed by introducing the self-embedding technology,which can achieve both copyright protection and content authentication.At the embedding side,an original image is split into non-overlapping blocks,and the m least significant bits of every pixel in each block are set to be zero.Then each block is conducted with singular value decomposition,and an original robust feature watermark is derived from judging the parity of the first digit of singular value′s norm from each block.Finally,a watermarked image is produced by self-embedding the original robust feature watermark into the m least significant bits of every pixel in each block.At the detection side,robust feature watermark′s extraction from an attacked watermarked image is similar to its production at the embedding end.Copyright identification is accomplished by calculating the normalized correlation between the extracted robust feature watermark and the original robust feature watermark.Content authentication is accomplished by tamper detection through judging the consistency between the extracted robust feature watermark and the m least significant bits of every pixel in each block of attacked image.Both theoretic analysis and experimental results illustrate that it has perfect invisibility.Experimental results also show that it not only has strong robustness towards attacks such as adding noise,cropping,JPEG compression,smoothing,resampling and geometric attacks like random row removal,right shifting and downward shifting,but also can accurately locate the tampered region and distinguish tamper type.Therefore,it can achieve dual purpose containing copyright protection and content authentication.

关 键 词：数字水印 自嵌入 版权保护 内容认证 篡改检测 恶意篡改 

分 类 号：TN911.7[电子电信—通信与信息系统]