%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%        author:王宇                     %
%   object name:基于浮點小波變換的水印方法 %
%   data:20/06/07                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
clc;
clear;
%讀取水印信息
Wfile_name='\shuiyin.jpg';
ma=double(imread(Wfile_name))/255;

%轉換成二值圖像
X=im2bw(ma,0.7);
%imshow(X);

%水印置亂 再取k=1,N=96,周期為24 這里做12次變換
[m,n]=size(ma);
[matrix,row1,col1]=chaos(X,3,96,12);

%置亂水印大小
[m1,n1]=size(matrix);
%混沌序列生成
randmtx=randCL(m1,n1,0.5,3.6);
%置換的序列同混沌序列做異或運算

for i=1:m1
    for j=1:n1
        if randmtx(i,j)>0.36
            randmtx(i,j)=0;
        else
            randmtx(i,j)=1;
        end
    end
end
matrix=xor(matrix,randmtx);

%matrix2=xor(matrix1,randmtx);
%kkk=matrix1-matrix2;
%讀取載體信息
file_name='\lena.bmp';
%Sorce=imread(file_name);
cover=double(imread(file_name));

%對載體圖像進行小波變化
[cA1,cH1,cV1,cD1] = dwt2(cover,'db4');

%取得高頻中的中間平均值kk,ll
%ave=average(cA1);
%[kk,ll]=SearchIndex(cA1,ave);

%設定嵌入的起始位置
%if (kk-m/2>0)&&(ll-n/2>0)
%    p1=kk-m/2;
%    p2=ll-n/2;
%else
%    p1=kk;
%    p2=ll;
%end
%高頻嵌入水印部分
%取模s=5 ,10,20所得效果不同
p1=22;p2=22;
for i=p1+1:p1+96
    for j=p2+1:p2+96
        temp(i-p1,j-p2)=mod(cA1(i,j),5);
    end
end
%kmin=min(kk);
%for i=1:38025
%    if abs(kk(i)-0.0043321)<0.0000001
%        kkk=i;
%    end
%end
%設定閾值T1,T2 圖像效果與T1,T2大小有關,其值越大效果越差
T1=2;T2=4;

%水印嵌入規則
for i=1:96
    for j=1:96
        if (matrix(i,j)==1)&(cA1(i+p1,j+p2)>=0)
            cA1(i+p1,j+p2)=cA1(i+p1,j+p2)-temp(i,j)+T1;
        end
        if (matrix(i,j)==0)&(cA1(i+p1,j+p2)>=0)
                cA1(i+p1,j+p2)=cA1(i+p1,j+p2)-temp(i,j)+T2;
        end
        if (matrix(i,j)==1)&(cA1(i+p1,j+p2)<0)
            cA1(i+p1,j+p2)=cA1(i+p1,j+p2)+temp(i,j)-T1;
        end   
        if (matrix(i,j)==0)&(cA1(i+p1,j+p2)<0)
            cA1(i+p1,j+p2)=cA1(i+p1,j+p2)+temp(i,j)-T2;
        end  
    end
end
                
%cA1 =double( idwt2(cA2,cH2,cV2,cD2,'db4',size(cA1)))/255;
A0 = double(idwt2(cA1,cH1,cV1,cD1,'db4',size(cover)))/255;
%保存水印圖片

imwrite(A0,'ImTemp.bmp','bmp');
image=imread('\ImTemp.bmp','bmp');
%image1=imnoise(image1,'gaussian',0.000005);
%imwrite(image1,'ImTemp.bmp','bmp');
%image=imread('\ImTemp.bmp','bmp');
imageY=file_name;
Ppsnr=psnr(cover,double(image));
figure(1);
%subplot(1,2,1);
imshow(image);
title('加入噪聲后含水印圖片')
%subplot(1,2,2);
figure(2);
imshow(X);title('水印');
figure(3);
imshow(matrix);title('經過混沌處理后置亂水印');
figure(4);
imshow(imageY);title('原圖像');