Abstract: In view of the problems for image content authentication and copyright protection，this paper proposes a fragile watermarking algorithm with high security，which can not only detect but also locate changes in images.The algorithm introduces a method which divides the original image into blocks for the location problems of geometric attacks.In view of the detection for original image operation，it proposes a kind of feature space decomposing method.The algorithm is robust to some limited scale and the intensity operation by choosing coefficients and constructing the extracting matrix，and it can implement blind detection too.The security of the algorithm is validated by the computer simulation.

摘要： 针对数字图像的图像内容认证和保护问题，提出一种具有高安全性的脆弱数字图像水印算法。算法不仅能够检测出图像是否被篡改，还可以对图像被篡改的内容进行定位。针对宿主图像的几何攻击的定位问题，算法采用了对原始宿主图像进行分块处理的方法。针对宿主图像操作（诸如压缩加噪）检测问题，算法采用了特征空间分解法。通过选择系数和构造提取矩阵，使得算法可以对某些限定范围和强度的操作具有鲁棒性，而且可以盲检测。算法的安全性通过计算机仿真给与验证。