hao.m

一个基于小波变换的彩色图像嵌入水印的算法

function dwtg1
clear all
clc;
%保存开始时间
%start_time=cputime;
figure(1);
%读出原始图像
subplot(1,2,1);
input=imread('flower.bmp');
imshow(input);
title('原始图像');
%读出水印
subplot(1,2,2);
water=imread('zh.bmp');
imshow(water);
title('水印');
%三色分离
input=double(input);
water=double(water);
inputr=input(:,:,1);%原始图像分离出R色
inputg=input(:,:,2);%原始图像分离出G色
inputb=double(input(:,:,3));%原始图像分离出B色
waterr=water(:,:,1);%水印图像分离出R色
waterg=water(:,:,2);%水印图像分离出G色
waterb=double(water(:,:,3));%水印图像分离出B色
%系数r大，增加鲁棒性，r小增加透明性
r=0.06;
%水印R的分解
[Cwr,Swr]=WAVEDEC2(waterr,1,'db1')
%水印的嵌入
[Cr,Sr]=WAVEDEC2(inputr,2,'db1');
Cr(1:size(Cwr,2)/16)=Cr(1:size(Cwr,2)/16)+r*Cwr(1:size(Cwr,2)/16);
k=0;
while k<=size(Cr,2)/size(Cwr,2)-1
    Cr(1+size(Cr,2)/4+k*size(Cwr,2)/4:size(Cr,2)/4+(k+1)*size(Cwr,2)/4)=Cr(1+size(Cr,2)/4+k*size(Cwr,2)/4:size(Cr,2)/4+(k+1)*size(Cwr,2)/4)+r*Cwr(1+size(Cwr,2)/4:size(Cwr,2)/2);
    Cr(1+size(Cr,2)/2+k*size(Cwr,2)/4:size(Cr,2)/2+(k+1)*size(Cwr,2)/4)=Cr(1+size(Cr,2)/2+k*size(Cwr,2)/4:size(Cr,2)/2+(k+1)*size(Cwr,2)/4)+r*Cwr(1+size(Cwr,2)/2:3*size(Cwr,2)/4);
    Cr(1+3*size(Cr,2)/4+k*size(Cwr,2)/4:3*size(Cr,2)/4+(k+1)*size(Cwr,2)/4)=Cr(1+3*size(Cr,2)/4+k*size(Cwr,2)/4:3*size(Cr,2)/4+(k+1)*size(Cwr,2)/4)+r*Cwr(1+3*size(Cwr,2)/4:size(Cwr,2));
    k=k+1;
end;
Cr(1:size(Cwr,2)/4)=Cr(1:size(Cwr,2)/4)+r*Cwr(1:size(Cwr,2)/4);
g=0.03;
%水印G的分解
[Cwg,Swg]=WAVEDEC2(waterg,1,'db1');
%图像G的分解
[Cg,Sg]=WAVEDEC2(inputg,2,'db1');
%水印的嵌入
Cg(1:size(Cwg,2)/16)=Cg(1:size(Cwg,2)/16)+g*Cwg(1:size(Cwg,2)/16);
k=0;
while k<=size(Cg,2)/size(Cwg,2)-1
    Cg(1+size(Cg,2)/4+k*size(Cwg,2)/4:size(Cg,2)/4+(k+1)*size(Cwg,2)/4)=Cg(1+size(Cg,2)/4+k*size(Cwg,2)/4:size(Cg,2)/4+(k+1)*size(Cwg,2)/4)+g*Cwg(1+size(Cwg,2)/4:size(Cwg,2)/2);
    Cg(1+size(Cg,2)/2+k*size(Cwg,2)/4:size(Cg,2)/2+(k+1)*size(Cwg,2)/4)=Cg(1+size(Cg,2)/2+k*size(Cwg,2)/4:size(Cg,2)/2+(k+1)*size(Cwg,2)/4)+g*Cwg(1+size(Cwg,2)/2:3*size(Cwg,2)/4);
    Cg(1+3*size(Cg,2)/4+k*size(Cwg,2)/4:3*size(Cg,2)/4+(k+1)*size(Cwg,2)/4)=Cr(1+3*size(Cg,2)/4+k*size(Cwg,2)/4:3*size(Cg,2)/4+(k+1)*size(Cwg,2)/4)+g*Cwg(1+3*size(Cwg,2)/4:size(Cwg,2));
    k=k+1;
end;

Cg(1:size(Cwg,2)/4)=Cg(1:size(Cwg,2)/4)+g*Cwg(1:size(Cwg,2)/4);
b=0.12;
%水印B的分解
[Cwb,Swb]=WAVEDEC2(waterb,1,'db1');
%图像B的分解
[Cb,Sb]=WAVEDEC2(inputb,2,'db1');
Cb(1:size(Cwb,2)/16)=Cb(1:size(Cwb,2)/16)+b*Cwb(1:size(Cwb,2)/16);
k=0;
while k<=size(Cb,2)/size(Cwb,2)-1
    Cb(1+size(Cb,2)/4+k*size(Cwb,2)/4:size(Cb,2)/4+(k+1)*size(Cwb,2)/4)=Cb(1+size(Cb,2)/4+k*size(Cwb,2)/4:size(Cb,2)/4+(k+1)*size(Cwb,2)/4)+b*Cwb(1+size(Cwb,2)/4:size(Cwb,2)/2);
    Cb(1+size(Cb,2)/2+k*size(Cwb,2)/4:size(Cb,2)/2+(k+1)*size(Cwb,2)/4)=Cb(1+size(Cb,2)/2+k*size(Cwb,2)/4:size(Cb,2)/2+(k+1)*size(Cwb,2)/4)+b*Cwb(1+size(Cwb,2)/2:3*size(Cwb,2)/4);
    Cb(1+3*size(Cg,2)/4+k*size(Cwb,2)/4:3*size(Cb,2)/4+(k+1)*size(Cwb,2)/4)=Cr(1+3*size(Cb,2)/4+k*size(Cwb,2)/4:3*size(Cb,2)/4+(k+1)*size(Cwb,2)/4)+b*Cwb(1+3*size(Cwb,2)/4:size(Cwb,2));
    k=k+1;
end;
Cb(1:size(Cwb,2)/4)=Cb(1:size(Cwb,2)/4)+b*Cwb(1:size(Cwb,2)/4);
%图像的重构
inputr=WAVEREC2(Cr,Sr,'db1');
inputg=WAVEREC2(Cg,Sg,'db1');
inputb=WAVEREC2(Cb,Sb,'db1');
%三色的叠加
temp=size(inputr);
  pic=zeros(temp(1),temp(2),3);
  for i=1:temp(1);
      for j=1:temp(2);
          pic(i,j,1)=inputr(i,j);
          pic(i,j,2)=inputg(i,j);
          pic(i,j,3)=inputb(i,j);
      end
  end
  output=uint8(round(pic));
  %转化为unit8
  watermarked_image_uint8=uint8(output);
  imwrite(watermarked_image_uint8,'watermarked.bmp','bmp');
  %显示时间
 % elapsed_time=cputime-start_time
  %输出结果
  figure(2);
  imshow(watermarked_image_uint8);
  title('水印图像');