基于混沌映射的空域彩色图像复合加密算法  

Composite Encryption Algorithm of Spatial Color Image Based on Chaotic Mapping

作　　者：王潇[1] WANG Xiao(School of Information Engineering,Xi’an Fanyi University,Xi’an 710105,China)

机构地区：[1]西安翻译学院信息工程学院,西安710105

出　　处：《吉林大学学报（信息科学版）》2022年第6期1026-1032,共7页Journal of Jilin University（Information Science Edition）

基　　金：2019年校级计算机基础课程教学团队基金资助项目(T1901)。

摘　　要：针对彩色图像安全性差、加密效率缓慢等问题,设计一种基于混沌映射的空域彩色图像复合加密算法。构建深度残差网络,在残差单元块内添加跳跃连接,创建含噪图像的非线性映射,将激活函数移动到卷积层,加快网络收敛速率的同时实现图像去噪目标;对图像采取小波变换操作,分析图像空域特征,利用多普勒波对图像的高、低频系数进行像素置乱,利用扩散操作计算图像对称点近邻区域,将待扩散像素点根据零均值归一化互相关分数排列组合,令混沌序列与图像具备充足耦合关联,强化图像安全性能;在Logistic混沌映射中引入映射参数,调节映射变量随机值,计算混沌系统序列概率分布函数,完成彩色图像复合加密。仿真结果证明,所提方法能有效消除彩色图像像素特征信息,加密效果良好,可行性强。Aiming at the problems of poor security and slow encryption efficiency of color image, a spatial color image composite encryption algorithm based on chaotic mapping is designed. The depth residual network is constructed, the jump connection is added in the residual unit block, the nonlinear mapping of noisy image is created, and the activation function is moved to the convolution layer to accelerate the convergence rate of the network achieving the goal of image denoising. The wavelet transform operation is adopted for the image to analyze the spatial characteristics of the image, the Doppler wave is used to scramble the high and low frequency coefficients of the image, the diffusion operation is used to calculate the adjacent area of the symmetrical points of the image, and the pixels to be diffused are arranged and combined according to the zero mean normalized cross-correlation score, so as to make the chaotic sequence have sufficient coupling correlation with the image and strengthen the image security. The mapping parameters are introduced into Logistic chaotic mapping, the random values of mapping variables are adjusted, the probability distribution function of chaotic system sequence is calculated, and the composite encryption of color image is completed. Simulation results show that the proposed method can effectively eliminate the pixel feature information of color image, and the encryption effect is good and feasible.

关 键 词：混沌映射 复合加密 图像去噪 小波分析 置乱变换 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]