一种基于外边缘的文档水印技术

数字水印是多媒体版权保护和内容防篡改的重要手段之一。针对二值英文纯文本图像,深入分析二值英文纯文本图像本身的结构特点,并在此基础上结合人类视觉特性,提出了一种易碎性数字水印方案。首先将文本图像分块,使每一图像子块仅包含一个英文单词,然后提取该单词块的外边缘点,从中随机选一部分点,嵌入水印信息。实验结果表明,该算法在不破坏图像质量的基础上,能有效抵抗噪音和局部篡改等攻击,同时又能抵抗和定位对文本内容的局部篡改。

A New Effective Document Water-Marking Technique Based on Outside Edges

Digital watermarking is a key technique for copyright protection and content slight change detection for a multimedia document. In this paper, the characteristic of the binary document image is analyzed in detail, thus a new effective technique is proposed based on the above analysis and human vision system. First, the original document image is cut into several parts, each of which includes only one word. Then the outside edge pixels of each part are extracted, from which some are selected randomly to embed the watermark bit. The experiment shows the algorithm does not deteriorate the quality of the watermarked image, but it can resist attacks such as noise and local tampering, in addition, it can be used to detect and locate the slight changes of the document image content.