基于Logistic混沌映射的图像加密通信系统研究

摘要

基于二维图像离散余弦变换(DCT)和Logistic混沌映射设计一种图像加密通信系统.首先基于DCT将图像变换成频域系数,利用Logistic映射产生的随机序列对变换得到的频域系数进行排序,对改变后的DCT系数分布结构做离散余弦反变换,得到置乱图像;.然后利用Logistic映射结构简单、复杂度高等特性,在像素替换过程中利用辅助密钥修正系统初始值,并按图像像素空间位置奇偶序号依次构造加密密钥,同时将像素点灰度值加密处理,最终实现图像信息的加密通信.%An image encryption communication system based on Discrete Cosine Transform (DCT) and Logistic map is proposed. Firstly, using the DCT and random sequences from Logistic map, a shuffled image is obtained. Then, the security key is constructed by modifying the initial value of Logistic map. Finally, we realized the image encryption communication system by dealing with the gray values of the encrypted image.