一种面向CT图像的无损水印算法  

A Lossless Watermarking Algorithm for CT Image

作　　者：高中文[1] 张玮[1] 余璟飞[1] 

机构地区：[1]哈尔滨理工大学自动化系,黑龙江哈尔滨150080

出　　处：《计算机技术与发展》2010年第8期171-175,共5页Computer Technology and Development

摘　　要：为了解决信息隐藏和篡改定位不能同时进行的问题,提出了一种篡改定位精度高的、规范化的无损水印算法。在CT图像的感兴趣区域内,提出了利用提升小波变换进行篡改定位的方法,来对感兴趣区域内的篡改进行定位。在感兴趣区域外,对选取的LSB进行算数编码来获得信息冗余,以嵌入水印信息。设计了一个规范的信息头来存储感兴趣区域的坐标等信息。水印在提取时,只需用一个密钥将信息头提取出之后再根据信息头提取其它数据。原始图像在水印提取后可无失真地恢复,且对恶意篡改的定位达到像素级。In order to solve the problem that information hiding and tamper localization can not be carried out at the same time,present a normalized lossless watermarking algorithm which has higher precision of tamper localization.Within the region of interest in the CT image,a tamper localization algorithm based on lifting wavelet transformation is presented to position the tampering.Outside the region of interest,arithmetic encoding of the selected LBS to get information redundancy to embed watermark information.Design a standard message header to save information such as coordinates of the region of interest,etc.Watermark extraction needs only a key to extract message header and then extract other messages according to message header.The original CT image can be restored without distortion after watermark has been extracted,and positioning accuracy to tamper localization was achieved pixel-level.

关 键 词：无损水印 医学图像认证 提升小波变换 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]