去噪matlab程序奇异值分解,一个基于奇异值分解的数字水印源代码matlab程序

内容：

一个基于奇异值分解的数字水印源代码，其中可以实现混沌之乱和奇异之分解的数字水印嵌入

clc

close all

clear all

% 保存开始时间

start_time=cputime;

iTimes=4;     %置乱次数

alpha=0.2;

blocksize=8;    % 设置块的大小

% 读入原图像

file_name='_lena_std_bw.bmp';

cover_ =double(imread(file_name));

% 原图像的行数与列数

Mc=size(cover_ ,1);        %原图像行数

Nc=size(cover_ ,2);        %原图像列数

%k=Mc*Nc/64;

% 最大嵌入信息量

max_message=Mc*Nc/(blocksize^2);

% 读入水印图像

file_name='xj.bmp';

I=imread(file_name);

message=double(I);

%%水印图像的行数与列数

Mm=size(message,1);                %水印行数

Nm=size(message,2);                %水印列数

message_vector=reshape(message,1,Mm*Nm);

% 检查水印信息是否过大

if (Mm*Nm> max_message)

error('水印太大')

end

%对水印图像进行arnold置乱

% if Mm~=Nm

%   error('水印矩阵必须为方阵');

% end

% if Mm~=48

%   error('必须为40*40大小,或者修改置乱次数');

% end

%

% tempImg=message;

% for n=1:iTimes % 次数

%   for u=1:Mm

%     for v=1:Nm

%       temp=tempImg(u,v);

%       ax=mod((u-1)+(v-1),Mm)+1;

%       ay=mod((u-1)+2*(v-1),Nm)+1;

%       outImg(ax,ay)=temp;

%     end

%   end

% tempImg=outImg;

% end

% message_vector=reshape(outImg,1,Mm*Nm);

message_vector=reshape(message,1,Mm*Nm);

%    sequence1=round(rand(1,7));

%   sequence2=round(rand(1,7));

sequence1=[1 0 1 1 0 0 0];

sequence2=[0 0 1 0 0 1 1];

% sequence1=rand(1,7);

% sequence2=rand(1,7);

% for i=1:7

%      if sequence1(i)<0.333

%     sequence1(i)=-1;

%计算总个数及编码后长度f 0.333

%     sequence2(i)=0;

% else 0.666

%     sequence2(i)=1;

% end

% end

%

k=1;

x=1;

y=1;

for (kk = 1:length(message_vector))

% 对块进行SVD变换

[u,s,v] = svd(cover_ (x:x+blocksize-1,y:y+blocksize-1));

s_orig(x:x+blocksize-1,y:y+blocksize-1)=s;

s1(1,1)=s(1,1);

if (message_vector(kk) == 1)

for i=2:8

s1(i,i)=s(i,i)+alpha*sequence1(i-1);

end

elseif (message_vector(kk) == 0)

for i=2:8

s1(i,i)=s(i,i)+alpha*sequence2(i-1);

end

end

%重新排序，并记录位置

%    s1=diag(s1)';a=s1(2:8);

%        s1=sort(s1);

%        s1=fliplr(s1);

%         for i=2:8

%             index(i-1)=find(s1(i)==a);

%         end

%        order(:,k)=index';

%     s1=diag(s1);

[u1,s11,v1]=svd(s1);

watermarked_image(x:x+blocksize-1,y:y+blocksize-1)=u*s11*v';

u_orig(x:x+blocksize-1,y:y+blocksize-1)=u;

v_orig(x:x+blocksize-1,y:y+blocksize-1)=v;

u1_orig(x:x+blocksize-1,y:y+blocksize-1)=u1;

v1_orig(x:x+blocksize-1,y:y+blocksize-1)=v1;

k=k+1;

% 移动到下一块

if (x+blocksize) >= Nc

x=1;

y=y+blocksize;

else

x=x+blocksize;

end

end

watermarked_image_uint=uint8(watermarked_image);

imwrite(watermarked_image_uint,'svd_watermarked.bmp','bmp');

figure

subplot(1,2,1);

imshow(watermarked_image,[]);

('原始图像');

subplot(1,2,2);

imshow(cover_ ,[])

('嵌入水印图像');

figure

imshow(I);

iTimes=8;         %置乱次数

% 保存开始时间

start_time=cputime;

blocksize=8;    % 设置块的大小

% 读入嵌入水印图像

file_name='svd_watermarked.bmp';

watermarked_image=double(imread(file_name));

% 嵌入水印图像的行数与列数

Mw=size(watermarked_image,1);        %嵌入水印图像的行数

Nw=size(watermarked_image,2);        %嵌入水印图像的列数

% 将图像分块提取水印

x=1;

y=1;

k=1;

for (kk = 1:max_message)

% 对块进行svd变换

[u11,s111,v11] = svd(watermarked_image(x:x+blocksize-1,y:y+blocksize-1));

d=u1_orig(x:x+blocksize-1,y:y+blocksize-1)*s111*v1_orig(x:x+blocksize-1,y:y+blocksize-1)';

sequence3=diag((d-s_orig(x:x+blocksize-1,y:y+blocksize-1)))';

sequence3=fix(sequence3(2:8));

%    ss=u(x:x+blocksize-1,y:y+blocksize-1)'*watermarked_image(x:x+blocksize-1,y:y+blocksize-1)*v(x:x+blocksize-1,y:y+blocksize-1);

%        ss=diag(s);

%        sequence3=ss(2:8)';

%

% %              sequence1=sequence1(order(:,k)');

% %              sequence2=sequence2(order(:,k)');

% %

relation1=corr2(sequence3,sequence1);

relation2=corr2(sequence3,sequence2);

if relation1>relation2

message_vector(kk)=1;

else

message_vector(kk)=0;

end

% 移动到下一块

k=k+1;

if (x+blocksize) >= Mw

x=1;

y=y+blocksize;

else

x=x+blocksize;

end

end

% arnold置乱

% tempImg=reshape(message_vector(1:Mm*Nm),Mm,Nm);

%  %tempImg=message_vector;

% message_arnold=tempImg;

% for n=1:iTimes % 次数

%   for u=1:Mm

%     for v=1:Nm

%       temp=tempImg(u,v);

%       ax=mod((u-1)+(v-1),Mm)+1;

%       ay=mod((u-1)+2*(v-1),Nm)+1;

%       outImg(ax,ay)=temp;

%     end

%   end

% tempImg=outImg;

% end

% message=outImg;

% 将message重新排列

message_vector=message_vector(1,1:Mm*Nm);

message=reshape(message_vector,Mm,Nm);

% 显示运行时间

elapsed_time=cputime-start_time,

% 显示提取水印与原始水印

figure

subplot(1,2,1);

imshow(message,[]);

('提取水印');

subplot(1,2,2);

imshow(I);

('原始水印');

p=corr2(I,message)

p1=corr2(cover_ ,watermarked_image)

psnr=psnr(cover_ ,watermarked_image)

for i=1:50

zaosheng=round(rand(48,48));

p(i)=corr2(I,zaosheng);

p(10)=corr2(I,message);

end

figure

plot(p);