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.
出处
《计算机技术与发展》
2010年第8期171-175,共5页
Computer Technology and Development
关键词
无损水印
医学图像认证
提升小波变换
lossless watermarking
medical image authentication
lifting wavelet transformation
