【摘要】 针对政府文件、银行支票、合同和证书等数字文档的完整性检测和真实性认证问题,提出了一种基于平滑性的文档水印算法.利用像素翻转前后其邻域内水平方向和竖直方向的平滑性不变来判断可嵌入块,然后将水印信息嵌入;检测时通过提取可嵌入块的中心像素得到水印信息.实验结果表明,水印的不可见性好,简单有效.该算法水印提取既不需要原始图像,也不需要原始水印,能对含水印文档图像的篡改进行检测并准确定位.更多还原

【Abstract】 A fragile document watermarking algorithm based on image smoothness for authentication,integrity verification and tampering detection of government documents,bank checks,contracts and certificates is presented.Flip ability of the central pix is determined by the smoothness along the horizontal and vertical direction in 3×3 neighborhood,the watermarking is embeded in the image block.The watermarking is performed by extracting the central pix in the embeddable blocks.Experiments show that the watermarked document image has a good quality and the embedded watermarking can be extracted without the original document image and the original watermarking.The proposed algorithm is simple and applicable.The tampered content can be detected and localized successfully.更多还原