一种图像篡改可恢复的认证水印方法

摘要

针对数字图像的篡改恢复问题,提出一种自嵌入的脆弱认证水印方法.提取图像2×2分块的灰度均值,经混沌映射加密、嵌入位平面确定和自同构映射后,作为水印信息嵌入原始图像所有像素的2个最低有效位中.该方法在图像认证时无需原始图像和任何有关水印的附加信息,可实现对细小图像篡改的准确检测定位并恢复到图像分块.实验结果与分析表明,该方法对任意的篡改极其敏感,恢复图像质量较好,安全性能较高.%Aiming at the image tamper restore problem, this paper proposes a self-fragile authentication watermark embedding method. The method extracts the image sub-block size of 2×2 gray mcan by chaotic encryption mapping to determine the embedded bit-plane and the automorphism mapping information as a watermark, embeds it into the original image for all pixels in the two least significant bit. This method does not need any original image and additional information relating to a watermark, it can implement the exact detection and location of small image tampering and restore it to the image sub-block. Experiment and analysis show that the method of arbitrary tampering with extremely sensitive to restore image quality and better safety performance.