中文摘要：

提出了一种适用于图像内容认证的基于Tchebichef矩的半脆弱图像数字水印算法。水印嵌入时首先将图像分块，然后使用查找表法快速计算图像块的Tchebichef矩，最后通过修改每个图像块的Tchebichef矩来嵌入水印。水印提取过程是嵌入过程的逆过程，实现了盲水印提取。实验表明，算法透明性较好，对于常见的攻击，如JPEG压缩、加性噪声、小角度的旋转缩放攻击、亮度／对比度攻击以及高斯低通滤波等具有很好的鲁棒性。

英文摘要：

A novel semi-friagile watermarking algorithm based on Tchebichef moments is proposed. In the watermark embedding procedure, the image is divided into blocks fitstly. The Tchebichef moment of each block is computed rapidly with the help of look-up-table and modified to embed a watermark. The watermark extraction is the reverse progress of the watermark embedding withast its original image . Experimental results demonstrate that the proposed watermarking technique has a good vision performance and the robustness against some attacks such as JPEG compressing, noises, little rotation or scale, luminance or contrast enhancement and Gaussion low pass filtering. In the cut and paste experiments, the proposed algorithm can occurately locate the tempered positions. More importantly, the proposed scheme can locate where the paste comes from in the paste experiments.