结合SCAN方法与离散小波变换的无损彩色图像加密算法

LOSSLESS COLOR IMAGE ENCRYPTION ALGORITHM COMBINING SCAN METHOD AND DISCRETE WAVELET TRANSFORM

基于提高图像在移动互联网传输的安全性,结合SCAN与二维离散小波设计一种无损的彩色图像加密方案。彩色明文图像被划分为红、绿、蓝三分量,并对其分块处理;由两个混沌系统生成随机序列,作为SCAN方法得扫描路径扰乱或扩散;利用二维离散小波变换将图像从空域转化到频域进而产生子带矩阵,根据上述产生的随机序列对子带矩阵进行置乱;利用二维逆离散小波变换将图像转化到空域,得到密文图像。实验结果表明,该算法的像素相关性较低,且密钥空间大,是一种无损的彩色图像加密算法。

In order to improve the security of image transmission in mobile Internet, a lossless color image encryption scheme was designed based on SCAN and two-dimensional discrete wavelet transform. Color plaintext images were divided into three components： red, green and blue, and their blocks were processed. The random sequence generated by two chaotic systems was used as the SCAN to get the disturbance or diffusion of the scanning path. The two-dimensional discrete wavelet transform was used to transform the image from the spatial domain to the frequency domain, and then the sub-band matrix was scrambled according to the random sequence generated above. Two-dimensional inverse discrete wavelet transform was used to transform the image into the spatial domain and obtain the cipher-text image. Experimental results show that the algorithm has low pixel correlation and large key space, which is a lossless color image encryption algorithm.