基于Tchebichef矩和小波提升的数字水印算法

提出一种基于Tchebichef矩和小波提升的抵抗几何攻击的内容认证水印算法，对图像进行一次小波提升分解，计算其低频成分的Tchebichef低阶矩不变量来构建水印系统。水印认证过程只须计算图像的几个低阶Tchebichef矩不变量。将该算法与基于几何矩不变量的算法进行比较。结果表明，该算法简单、有效，对旋转、缩放、剪切等几何攻击以及JPEG压缩等攻击具有较高的稳健性。

Digital Watermark Algorithm Based on Tchebichef Moments and Wavelet Lifting

The watermark based on Tchebichef moments and wavelet lifting is used in an authentication context.After the discrete lifting wavelet transform,the lower order Tchebichef invariant moments of the sub band coefficients are computed.The processing of the encoder and the decoder is simple,and a few low order moments need to be calculated.The algorithm is compared with the algorithm based on the geometric moments.Results show that the scheme is simple,effective.It has high stabilities of geometrical attacks of ...