基于混沌和傅里叶变换的数字水印算法

摘要

A digital watermarking algorithm is proposed based on chaotic map and fractional Fourier transform. Design a binary image as a watermark , and encrypt it by a chaotic map under the control of the secret key. The original digital image is fractional Fourier transformed with the chaotic sequences generated by the key, and the watermark is embedded in the phase spectrum coefficient. Finally the watermarked image can be obtained by inversely fractional Fourier transformation. The experimental results show that the algorithm is simple, invisible, and robust against crop, compression, added noise and rotation.%提出一种基于混沌映射和分数阶傅里叶变换的数字水印算法.采用有版权信息的二值图像作为水印,利用混沌映射在密钥的控制下对水印进行加密置乱.利用由密钥生成的混沌序列对数字图像进行分数傅里叶变换,并将已经混沌置乱的水印信息嵌入到原始图像的中频幅度谱系数对应的相位谱系数中,最后进行分数傅里叶逆变换可以得到嵌入水印的图像.通过仿真实验可以证明该算法简便易行,且具有良好的不可见性,对图像的剪切、压缩、添加噪声和旋转一系列的图像攻击操作具有良好的鲁棒性.