实验报告：混沌同步控制与图像加密(7)

加密，加密程序如下：

function jiami clc; clear all; global M; global N; global Ximage; global Yimage;

Ximage=double(imread('C:\Program Files\MATLAB71\work\lena.gif')); key1=0.1; key=4;

[M,N]=size(Ximage); figure(1)

imshow(Ximage,[]); Ximage=double(Ximage); for(i=1:M) for(j=1:N)

key1=key*key1*(1-key1); a(i,j)=key1; end end key2=0.2; for(i=1:M) for(j=1:N)

key2=key*key2*(1-key2); b(i,j)=key2; end end

x=0.4*a+0.6*b; e=round(x*256); tt=0.01;

Yimage=tt*Ximage+(1-tt)*e; figure(2)

imshow(Yimage,[]); %%置乱度分析

Yimage=double(Yimage);

sx=sum(sum((Ximage-256*rand(M,N)).^2)); DD=sy/sx %置乱度 comeback; %解密

解密程序：

function comeback global M; global N;