基于DCT变换的信息隐藏(数字水印)嵌入算法的设计.

%------------------------------------------------------------------%

% 基于DCT变换的信息隐藏(数字水印嵌入算法的设计% % %-----------------------------------------------------------=------%

clear all; close all; clc

%-----------------读入"W"，并进行WPP处理--------------------- wm0=imread('watermark.bmp';

% wm0=imresize(wm0,[64 64]; [Mm,Nm]=size(wm0 ; %计算水印图象的高度和宽度n=Mm*Nm;

subplot(131

imshow(wm0;

title('my watermark'; wm=double(wm0;

for i=1:Mm for j=1:Nm if wm(i,j==0 wm(i,j=-1;

end

end

end

%-----------------------读入"C"，并进行CPP处理-------------------------- % cover_image=imread('cameraman.tif'; cover_image=imread('lena.bmp';

[Mc,Nc]=size(cover_image; %计算载体图象的高度和宽度

subplot(132;

imshow(cover_image;

title('my coverimage'; cover_image=double(cover_image;%读入原始宿主图象，并转换为双精度数组

%------------------分块DCT变换,嵌入水印----------------------------

%设置水印嵌入强度% k=369; k=70;

%设置嵌入位置x=3;

y=5;

%设定图象的分块大小为8*8 blocksize=8;

c=Mc/blocksize;

d=Nc/blocksize;

m=c*d;%计算图象划分的图象块

%判断载体图像尺寸是否适合水印大小if n>m error('^_^ Dear classmates~~~~~~The watermark is too large to be imbeded into the coverimage,hehe~~~';

end

%分块DCT变换，嵌入水印for j=1:c for i=1:d dct_block=dct2(cover_image((1+(j-1*8:j*8,(1+(i-1*8:i*8;

dct_block(x,y=k*wm(j,i;

watermarked_image((1+(j-1*8:j*8,(1+(i-1*8:i*8=idct2(dct_block;

end

end

%------------------------------------------------------------------

%生成并输出嵌入水印后的图象imwrite(uint8(watermarked_image,'watermarked_image.bmp','bmp';

%显示嵌入水印后的图象subplot(133;

imshow(uint8(watermarked_image

title('watermarkedImage'

隐藏信息提取程序，我写的！

clear all ; close all ; clc

%定义一个空空间来存储提取的水印wm_image=zeros(32,32;

% subplot(122; % imshow(wm_image;

%read the marked image and transfer it to double precise %-------------------------------------------------------

watermarked_image=imread('watermarked_image.bmp';

[M_marked,N_marked]=size(watermarked_image;

subplot(121;

imshow(watermarked_image;

title('The marked image' ; watermarked_image=double(watermarked_image;

blocksize=8;

k=1/70;

x=3;

y=5;

c=M_marked/blocksize;

d=N_marked/blocksize;

for j=1:c for i=1:d dct_markedblock=dct2(watermarked_image((1+(j-1*8:j*8,(1+(i-1*8:i*8;

if k*dct_markedblock(x,y>0 wm_image(j,i=1;

else

vm_image(j,i=0;

end

end

end

subplot(122;

imshow(wm_image;

title('mark image'; imwrite((wm_image,'MYwm_image.bmp','bmp';