基于小波与分数傅里叶变换的图像水印算法

载体图像的空域隐藏Chirp信号可以通过分数傅里叶变换在变换域中进行盲检测。为了提高该算法的鲁棒性能，该文研究直接离散化方法，合理选取分数傅里叶变换的算子阶数，将Chirp 信号隐藏在图像信号的低频小波域中。仿真实验表明，改进后的水印算法提高了直接在空域进行信息隐藏的鲁棒性。

Image Watermarking Algorithm Based on Wavelet and Fractional Fourier Transform

Chirp signal used as watermarking can be hidden in the spatial domain of the host image, and the watermarking is detected blindly through the fractional Fourier transform in the transform domain. To enhance the robust performance of the algorithm, this paper analyzes the reasonable order of fractional operator for direct discrete Fourier transform method, and hides a Chirp signal into low frequency wavelet-domain. Experiments show that the improved blind watermarking detection algorithm is robuster than the algorithm which embedded watermarking into the special domain of the host image, and can detect the Chirp watermarking rapidly.