应用混沌序列对有意义水印进行调制

附录1.1 应用混沌序列对有意义水印进行调制

% designed by 李立宗

% lilizong@gmail.com

% logistic.m

a=imread('e:\logo.bmp');

x=zeros(1,40000);

t=zeros(1,40000);

x(1)=0.8;

for i=1:39999

%x(i+1)=4*x(i)*(1-x(i));

x(i+1)=1-2*x(i)*x(i);

end

% figure,imshow(a);

%

% for i=1:200

%for j=1:200

%if a(i,j)==255

% a(i,j)=1;

%else

% a(i,j)=0;

%end

%end

% end

%

% figure,imshow(a);

a=im2bw(a);

subplot(2,2,1),imshow(a),title('水印图像');

for i=1:40000

if x(i)>0

t(i)=1;

else

t(i)=0;

end

end

for i=1:200

for j=1:200

temp(i,j)=t((i-1)*200+j);

end

end

% subplot(1,2,1),imshow(temp);

% temp=ones(200:200);

subplot(2,2,2),imshow(temp),title('混沌加密图像');

w1=xor(temp,a);

subplot(2,2,3),imshow(w1),title('加密后水印图像');

a1=xor(w1,temp);

subplot(2,2,4),imshow(a1),title('恢复后图像');