一种用于二值文本图像认证的水印算法

A Digital Watermarking Algorithm for Binary Text Image

提出了一种用于二值文本图像内容认证的脆弱型数字水印算法.该算法利用图像分块后每个像素块边缘部分的像素值产生混沌迭代初值,经混沌迭代及量化后生成水印信息.通过在图像块的中间部分查找3×3邻域各方向平滑度改变量小的点作为颜色翻转点,从而将水印信息嵌入.实验结果表明,该算法具有较好的不可见性及篡改检测和篡改定位能力.

A fragile watermarking algorithm is presented, which can be applied to binary text image verification. Based on the value of image block edges, the initial values of chaotic mapping are produced. By iterating several times of the chaotic mapping, the watermark is obtained and embedded into the pixels, which have prior embeddibility for 3 x 3 neighborhood pattern. The experimental results show that the watermarked binary image have good visual quality and that the algorithm can detect and localize precisely the tampers on the watermarked images.