图象加密.txt

基于matlab的图形图象加密算法

clear
x_mi=0.123;
u=3.6;
I=imread('c:\matlab6p5\work\Image00006.bmp');
figure,Imshow(I);
Arr_size=size(I);
High=Arr_size(1)
Length=Arr_size(2)
a=x_mi;
x_arr=a;
for k=2:8
    b= u*a*(1-a);
    x_arr=[x_arr,b];
    a=b;
end
arr_sum=sum(x_arr);
i=round(x_arr(1)/arr_sum*Length);
x_i=1;
x_i=[x_i,i];
a=i+1;
for k=2:7
i=round(x_arr(k)/arr_sum*Length);
a=a+i; 
x_i=[x_i,a];
end
x_sub=I(:,x_i(1):x_i(2)-1);
g_sub=round(double(x_arr(1))*255/2+double(x_arr(1))*double(x_sub)*255/2);
G=g_sub;
for k=3:8
x_sub=I(:,x_i(k-1):x_i(k)-1);
g_sub=round(double(x_arr(k-1))*255/2+double(x_arr(k-1))*double(x_sub)*255/2);
G=[G,g_sub];
end
x_sub=I(:,x_i(8):Length);
g_sub=round(double(x_arr(1))*255/2+double(x_arr(1))*double(x_sub)*255/2);
G=[G,g_sub];
I_show=mat2gray(double(G));
figure,Imshow(I_show);
%行列变换
X_map=I_show;
a=X_map(1,:);
b=X_map(:,1);
for j=1:Length-1
X_map(:,j)=X_map(:,j+1);
for i=1:High-1
X_map(i,:)=X_map(i+1,:);
end
X(:,Length)=b;
end
X(High,:)=a;
I_show=mat2gray(double(G));
figure,Imshow(X_map);