基于离散余弦和Contourlet混合变换域的图像水印方案

A scheme of digital image watermarking based on DCT and contourlet transform domains

针对多媒体资源的版权保护问题，结合离散余弦变换和Contourlet变换的优点，提出了一种基于离散余弦变换和Contourlet混合变换域的数字图像水印算法．该算法采用二值图像作为水印，利用混沌映射对水印图像进行加密．将水印嵌入到人眼最不敏感的蓝色分量的离散余弦和Contourlet混合变换域的低通采样逼近子带中，增加了嵌入信息容量．仿真结果表明该水印算法不仅具有较好的安全性、不可见性和稳健性，而且水印采用盲提取，不需要载体图像的信息，更有利于实际应用．

A digital image watermarking algorithm based on combination of discrete cosine transform （DCT） and contourlet transform is proposed for copyright protection of multimedia resources. A binary image is used as a watermark in the proposed algorithm. Use of chaos map to encrypt watermark image. The watermark was embedded into the human eye is most sensitive to blue component of discrete cosine transform and contourlet transform domain lowpass sampling approximation subband, increasing the embedded information capacity. The simulation results demonstrate that the efficiency of the proposed algorithm, they indicate that the proposed algorithm not only has good security, invisibility and robustness property but also doesn＇t need the carrier image when extracting the watermark, so it is closer to practical applieations.