基于频谱切割和二维Arnold变换的彩色图像加密算法

Color image encryption algorithm based on cutting spectrum and 2D Arnold transform

针对多通道彩色图像加密算法传输负担大的缺陷,提出了基于频谱切割和二维Arnold变换的单通道彩色图像加密算法。该算法对原彩色图像的RGB分量分别进行不同分数阶次的分数傅里叶变换(FrFT),将各分量所得频谱信息进行切割,组合成一幅新的频谱;再用二维Arnold变换对组合频谱进行置乱,使三个分量的频谱信息充分混淆和扩散。密文为一幅灰度图像,在保留原彩色图像主要信息的同时,减小了传输负担。仿真结果与性能分析验证了该算法的加密效果和安全性。

To reduce the heavy transmission burden of muhichannel color image encryption algorithms, a single-channel color image encryption algorithm based on cutting spectrum and 2D Arnold transform was presented. In the proposed algorithm, the R, G, B components of the original color image were extracted, and their spectra were obtained separately by the Fractional Fourier Transform （FrFT） of different orders, followed by cutting their spectra to construct a new spectrum, then the combined spectrum was scrambled by the 2D Arnold transform to confuse and diffuse the spectrum information well enough. The encrypted image was a gray image, thus the transmission burden was reduced apparently while the main information of the original color image was kept. The simulation results and performance analyses verify the validity and the security of the encryption algorithm.