基于MPDFRFT的数字水印算法

Watermarking algorithm in multiple-parameter discrete fractional Fourier transform domain

基于多参量离散分数阶Fourier变换(MPDFRFT)理论提出了一种数字水印算法,该算法首先将水印经Arnold变换进行置乱,然后根据分数阶Fourier变换具有空域和频域双域信息表达能力,分别对载体图象和所加水印进行不同阶次向量的多参量分数阶Fourier变换;将变换后的水印信息直接叠加到载体图象的特征区域内,然后进行反变换得到水印图象。在噪声、滤波、剪切和JPEG压缩等攻击方式下,对算法进行了鲁棒性分析,仿真实验结果表明该算法具有较强的鲁棒性和安全性。

An image watermarking algorithm was proposed based on multiple-parameter discrete fractional Fourier transform （MPDFRFT）. The watermark was firstly scrambled with Arnold transform by the algorithm. Then the algorithm took the advantage of space and frequency double domain signal representation property of the fractional Fourier transform. The original image and the watermark sequence were fractional Fourier transformed with different order vector, and watermarking signal transformed by FRFT was added in the characteristic area, the final watermark image was obtained by inversely transforming the joint spectra. The robustness of the watermark under different attacks such as noise, filter, crop and JPEG compression had been numerically analyzed also. Simulation experiment demonstrats that this algorithm has better robustness and security.