基于行移和字移编码的二值文本数字水印技术

Document marking technique based on both line and word shifting

针对文档是由字符、行、段落组成,而且字符之间、行之间具有一定距离的特点,提出在文档的竖直方向上利用行移编码嵌入水印,在文档的水平方向利用字移编码嵌入水印。在水印信息的嵌入过程中,提出了通过预处理实现移动行(字)与相邻两个控制行(字)之间的相对位置固定,使得水印信息的隐蔽性大大增加,在该处理算法的基础上,提出了水印信息的盲检测算法。从水印嵌入和提取的仿真试验结果可知,该方法具有较强的鲁棒性,最重要的是基于该算法的水印嵌入和检测实现比较简单而且有效。

A text document typically consists of a collection of regular structures such as words, lines, and paragraphs. In this paper we exploit this property to watermark formatted text documents by shifting slightly certain lines and words in order to discourage illicit distribution. We propose the pretreatment method that makes the distance between the shifting lines and its adjacent control lines holds fixed, Based on this method, we can use the document profiles directly for detection without any message. The proposed method has high detected probability and strong robust. It is important that this method of marking embeding and detecting is not only simple but also effective.