一种改进的多混沌系统彩色数字图像加密方案

摘要

提出一种改进的基于Logistic映射和Lorenz映射相结合的彩色图像加密方法。将三维空间的彩色图像转换成二维的灰度图像,分别利用Logistic、Lorenz混沌系统生成的混沌序列对二维图像进行像素位置与像素值的置乱,对置乱后的图像按折叠算法进行处理。Matlab仿真实验结果可知,转换成二维灰度图像后有效地降低了算法的计算强度和空间需求;置乱时实现了不同层次（R、G、B）亮度值的完全混合,取得了较好的加密效果,安全性更高。%An improved color image encryption scheme based on the combination of Logistic map and Lorenz system is given in this paper.The color image in 3-dimensional space is turned into the gray image in 2-dimensional space,and then the chaotic sequences generated by Logistic and Lorenz chaotic system are used to scramble the pixel position and pixel values in 2-Dimensional image respectively.The disordered image can be handled by folding algorithm.From the results of Matlab simulation,the strength of calculation and space requirement to the algorithm are descended after converting into 2-Dimensional gray-scale images.Different levels of（R,G,B） luminance values have been completely mixed in scrambling,thus achieving better encryption effects and high security.