一种基于空格编码的PDF文本数字水印算法  

A text digital watermarking algorithm for PDF document based on space encoding and scrambling technique

作　　者：顾艳春[1] 冯君婷[2] 

机构地区：[1]佛山科学技术学院电子与信息工程学院,广东佛山528000 [2]佛山市第一人民医院计算机中心,广东佛山528000

出　　处：《佛山科学技术学院学报（自然科学版）》2015年第1期76-80,87,共6页Journal of Foshan University(Natural Science Edition)

基　　金：佛山科学技术学院科研基金资助项目(2010X063)

摘　　要：提出一种基于空格编码和置乱技术的适用于PDF文档的文本数字水印算法。首先,将水印图像进行置乱变换;其次,将原PDF文档转换成PS文件,PS文件中保存有字符和位置信息。利用空格不可见的特点,在PS文件中叠加若干由空格组成的行,并利用空格的位置信息来嵌入水印信息值及水印的位置信息值;最后,将PS文件转换为含有水印的PDF文档。实验结果表明,该算法具有较好的可视性和鲁棒性。A text digital watermarking algorithm for PDF document based on space encoding and scrambling technique is proposed. The watermark image is first encrypted by scrambling technique. Then, the original PDF document is transformed into PS file, in which preserved the characters and their location information. Thirdly,we superimpose some rows composed of space into the PS file. The binary watermark image with its location information is embedded into the character spacing of the PS file. Finally, we get the PDF document containing watermark through the PS file. Experimental results demonstrate that the proposed algorithm is imperceptibility and robust to some degradation processes such as cropping.

关 键 词：信息隐藏 空格编码 置乱技术 文本数字水印 PDF文档 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]