基于图像内容的半易损水印认证算法

提出了一种用于图像完整性认证的基于内容的半易损数字水印算法。借助数字签名的思想。对原始图像进行哈希变抉，并用私钥对其加密。然后将加密后的信息作为水印信息，利用原始图像的HVS特性将水印信号嵌入到原始图像的小波域中。检测器同样对本身未作修改的部分作一次哈希变换，与原始水印信号进行比较，以此来验证图像的合法性。实验验证了该算法具有良好的鲁棒性和具有识别图像被篡改区域的能力。

A Semi-fragile Watermarking Algorithm Based on Image Content

A semi-fragile watermarking algorithm for content-based image authentication is proposed in this paper. Making use of digital signature, the original image is transformed by Hash fimction and is encrypted by their private key. Then the encrypted information will be acted as a watermark and utilized the HVS characteristics of the original image, the watermarking signal is embedded into the wavelet domain of the original image. In order to verify the legitimacy of this image, the unmodified part of image is transformed by Hash function and then Compared with the original image signal. The experimental results demonstrate that the proposed algorithm is robust and has the capacities of distinguishing the tampered region from image.