基于Contourlet变换和增强位平面的零水印算法

提出一种基于Contourlet变换和增强位平面的数字图像零水印算法。对原始载体图像进行Contourlet变换,利用其低频逼近子图的增强位平面和置乱后的水印图像进行一定运算得到构造图像,再加密成密钥图像。密钥图像被用来提取水印。最后给出了实验仿真结果,并和一般图像二值化零水印算法进行了比较。结果表明,该算法比较简单,不可觉察性很好,并对附加高斯噪声、中值滤波、联合图像专家组（JPEG）压缩等图像处理攻击有较强的鲁棒性。

Zero-watermarking Algorithm Based on Contourlet Transform and Enhanced Bit-planes

An image zero-watermarking algorithm based on enhanced bit-planes and Contourlet transform is proposed in this paper.The Contourlet transform is used to the original image and the constructed image is obtained by a certain calculation using the enhanced bit-planes of low-frequency sub component and the scrambled watermark image,at the same time,the secret image is generated.Secondly,the watermark image can be extracted from the secret image.The proposed algorithm is compared with the binary bitmap based algorithm in this paper.Extensive experimental results show that the proposed algorithm is simple,invisible and robust,to against some image processing attacks,such as additive Gaussian noise,median filtering,joint photographic experts group（JPEG） compression and so on.