基于双域信息融合的鲁棒二值文本图像水印  

Robust Double Domain Watermarking for Binary Document Image

作　　者：朱新山[1,2] 陈砚鸣[2] 董宏辉[3] 丁杰[2] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]扬州大学信息工程学院,江苏扬州225009 [3]北京交通大学轨道交通控制与安全国家重点实验室,北京100044

出　　处：《计算机学报》2014年第6期1352-1364,共13页Chinese Journal of Computers

基　　金：国家自然科学基金(60803122;61103018;61100120);江苏省基础研究计划(自然科学基金)项目(BK2011442;BK2012683);扬州大学科技创新培育基金(2012CXJ028);北大方正集团有限公司数字出版技术国家重点实验室开放课题资助~~

摘　　要：该文提出了一种适用于二值文本图像的双域水印方案.该方案生成水印模板作为离散余弦变换域信号,然后将其与要嵌入的信息进行调制.在水印嵌入之前,调制后的信号被变换到空间域中,并调整局部嵌入强度使得水印信号适合人类视觉系统的特征.水印提取采用相关检测器,可在变换域内或空间域内操作,而且,从理论上分析了感知整形过程与翻转像素点个数对水印提取的影响.为了抵抗水印同步信息损失,将提出的双域水印方案与一个图像归一化方案相结合.此归一化方案采用了文本倾斜检测与字符分割技术,适合于文本图像的特点.实验表明,提出的方案对常见的图像处理操作、几何攻击和打印-扫描过程具有良好的鲁棒性.This paper presents a double domain watermarking （DDW）method for binary docu ment image.In this method,the watermark patterns are generated as signals in the discrete cosine transform（DCT）domain,and modulated with the embedded message.The modulated signal is then transformed into the spatial domain and adapted to the characteristics of human visual system by adjusting the localized embedding strengths before embedding.Watermark extractions can be performed by applying a correlation based detector in either of the two domains.The effects of perceptually shaping and the number of the flipped pixels on watermark decoding are also analyzed carefully.The DDW method is combined with an image normalization procedure,which is developed particularly for document image through skew detection and character segmentation,in order to resist synchronization distortions.The experimental results show that the presented scheme manifests the good robustness against common image manipulations,geometrical attacks as well as print-scan process.

关 键 词：数字水印 二值文本图像 双域 鲁棒性 打印扫描 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]