一种基于灰度均匀分布的自适应文本可见水印算法  

A self-adaptive text visible watermarking algorithm based on uniform distribution of gray level

作　　者：李翔[1] 丁文霞[1] 

机构地区：[1]国防科学技术大学电子科学与工程学院,湖南长沙410073

出　　处：《计算机工程与科学》2013年第7期71-76,共6页Computer Engineering & Science

基　　金：国家自然科学基金资助项目(60902092)

摘　　要：文本可见水印技术主要用于明确文本类数字媒体的版权标识,防止非法使用。现有文本可见水印算法的抗二值化攻击能力较差,为克服此缺陷,根据文本图像的灰度分布和纹理的特点,提出了一种基于灰度均匀分布的自适应文本可见水印算法。首先提取文本行轮廓,然后依据行轮廓自适应产生嵌入强度,再由嵌入强度对水印黑色像素进行筛选,最后将载体文本与筛选后的水印映射到同一灰度范围。该算法具有嵌入强度自适应、嵌入位置随机和抗二值化攻击等特点。实验结果显示,算法在不影响载体文本可读性的同时,具有良好的水印可视性和鲁棒性,适用于任何形式的二值文本和图形水印。Text visible watermarking is mainly used for determining copyright of the text digital media in order to prevent illegal usage. In order to overcome the drawback that the existing text visible watermarking algorithms have weak binaryzation attack-resisting capability, the paper proposes a self-a- daptive text visible watermarking algorithm based on uniform distribution of gray level, according to the characteristics of gray level and texture of text image. Firstly, the row-outline of the cover text image is extracted, and the embedding strength of watermark is determined by the outline; Secondly, the embed- ding strength is used to select the black pixels of watermark. Finally, the cover text image and the wa- termark are mapped to the same gray-level range. The algorithm has advantages of adaptive embedding strength, random embedding position and strong binaryzation attack-resisting capability. The experi- mental results show that the algorithm has good visibility and robustness and it can apply to any forms of text and graphics watermark.

关 键 词：文本图像 可见水印 二值化攻击 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]