摘要
针对变换域的认证水印对舍入误差及像素值溢出非常敏感的问题,提出了一种新的带反馈的半脆弱水印算法(SAF算法),通过在嵌入过程中加入检测模块,并将检测模块的结果反馈,作为嵌入过程是否完成的判决条件,从而达到降低虚警概率的目的.由于运用了预量化原理,SAF算法能够对有损压缩后的系数进行重构,从而彻底地解决了JPEG压缩对水印信号破坏的问题.实验结果表明,SAF算法是一种有效且实用的认证水印算法.
The well-known adage that seeing is believing is no longer true due to the pervasive and powerful multimedia manipulation tools. To prevent image manipulations and fraudulent use of modified images, multimedia authentication techniques are being developed. But unfortunately there is a big problem in authentication watermarking algorithms which are in the transform (e.g., DCT) domain. Converting the modified transform coefficients back to the integer pixel domain and then converting them again to the transform domain may not get the same result. As a result, such a scheme would not authenticate images, even through they may not have been manipulated otherwise. Combining the embedding process with the performance analysis, a new semi-fragile authentication watermarking with feedback, called SAF, is presented. The embedding process in some image blocks is performed several times according to the results of the performance analysis of the watermarking detecting process. By the reconstruction of the DCT coefficient, SAF can accept JPEG lossy compression on the watermarked image to a pre-determined quality factor, and reject malicious attacks. The experimental results show its effectiveness in protecting the content-integrity of images.
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2004年第5期724-727,752,共5页
Journal of Xidian University
基金
教育部优秀青年教师资助计划资助项目
