基于IWT和SVD的数字图像水印算法

A Digital Image Watermarking Algorithm Based on IWT and SVD

针对传统SVD域数字图像水印算法存在过高虚警率的问题,提出了一种基于IWT和SVD的数字图像水印算法。算法先对载体图像进行1级IWT分解得到4个子带,然后对4个子带进行SVD变换,把水印图像信息直接嵌入到载体图像4个子带的奇异值中。在水印嵌入过程中提出了一种数字签名认证机制,利用生成的数字签名在水印嵌入的同时完成数字签名的嵌入来加密含水印的图像。在水印提取之前,先对数字签名进行验证来避免虚警的问题。实验表明,算法具有良好的视觉性和抵抗各类攻击的鲁棒性。

Aiming at the problem of high false alarm error rate of the classical SVD domain digital image watermarking algorithm, proposes a digital image watermarking algorithm based on IWT and SVD. Firstly, the algorithm performs 1 level of IWT decomposition on the copyright image to obtain 4 subbands, then performs the SVD transform to the 4 sub-bands. Secondly, it embeds the watermark image information directly into the singular values of the 4 sub-bands of the copyright image. It also proposes a digital signature authentication mechanism in the watermark embedding process to encrypte the watermarked image with the digital signature while processing the watermark embedding. Finally, before the watermark image being extracted, the digital signature is verified to avoid the problem of false alarm error. Experiments show that, this algorithm has good visuality and robustness to resist attacks.