dm_dct_fenkuai.rar_dm误码率_laugh-single.b_noise attacks_峰值信噪比_嵌入率

function [psnr,err]=dm_dct_fenkuai(step,attack_style,attack_strength) %%% attack_style 用于设置选择何种攻击 %%% step 用于设置量化步长 %%% err 返回误码率 %%% psnr 返回峰值信噪比 %%% attack_strength 用于控制攻击的强弱 %%%%%%%%%%%%%%%% 读入原始载体图像 %%%%%%%%%%%%%%%%%%%%%%%%%%% [x,map]=imread('lena.bmp'); [row,col]=size(x); M=row; N=col; MN=col*row; figure(1),imshow(uint8(x));%%; image(x), colormap(map); title('原始图像','Fontsize',16,'color','blue'); x_source=x; fun1=@dct2; J1=blkproc(x,[8 8],fun1); %%%分割图像进行二维DCT变换 %%%%%%%%%%%%%%%% 读入原始水印 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [m,mapm]=imread('laugh-single.bmp'); figure(2),imshow(m); title('嵌入的水印图像','Fontsize',8,'color','blue'); [rowm,colm]=size(m); MNm=rowm*colm; Mm=rowm; Nm=colm; mm=m(1:MNm); %%只有两个值，0和255 Rm=MNm/MN; %%%%%%%%%%%%%%% 抖动量化实现水印信息的嵌入 %%%%%%%%%%%%%%%%%%%%%%%%%%%% %% 计算(i,k)处的频率，用来判断(i,k)处是否进行抖动量化 for i=1:M for k=1:N if mod(i,8)==0||mod(k,8)==0 fre(i,k)=1; else fre(i,k)=(((mod(i,8)-1)/16)^2+((mod(k,8)-1)/16)^2)^(1/2); end end end %% 计算(i,k)属于哪个块，用来判断(i,k)如何进行抖动量化 for i=1:M for k=1:N block(i,k)=(M/8)*(ceil(i/8)-1)+ceil(k/8); end end b1=block(M,N); %总块数 L=fix(b1/MNm); %多少块嵌入1bit，为了解码方便，确保L为奇数 %进行抖动量化 %不进行纠错编码的情况下，产生抖动序列 z=mm; num=1; num1=1; num2=1; for i=1:fix(MN*Rm) d0(i)=-step/4; d1(i)=d0(i)+step/2; end for i=1:M for k=1:N if fre(i,k)>0.25 J11(i,k)=J1(i,k); else if block(i,k)>L*MNm J11(i,k)=J1(i,k); else if double(z(ceil(block(i,k)/L)))-255==0 %如果灰度为255 J11(i,k)=round((J1(i,k)+d1(ceil(block(i,k)/L)))/step)*step-d1(ceil(block(i,k)/L)); else J11(i,k)=round((J1(i,k)+d0(ceil(block(i,k)/L)))/step)*step-d0(ceil(block(i,k)/L)); end end end end end fun2=@idct2; J2=blkproc(J11,[8 8],fun2); %%%二维DCT逆变换 figure(3);imshow(uint8(round(J2))); imwrite(uint8(round(J2)),'dm_watermarked.bmp'); %%%%%%%%%%%%%%%% 计算峰值信噪比PSNR %%%%%%%%%%%%%%%%%%%%%%%% x_temp1=J2-double(x_source); figure(4),imshow(uint8(round(100*x_temp1))); imwrite((uint8(round(100*x_temp1))),'dm_chazhi.bmp'); x_temp2=x_temp1( : ); x_temp3=abs(x_temp2); x_temp4=x_temp3'*x_temp3; d_embed=x_temp4/(M*M); SDR1=255*255/d_embed; psnr=10*log10(SDR1); %%%%%%%%%%%%%%%% 攻击 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% J2=imread('dm_watermarked.bmp'); if attack_style==1 %%放大两倍操作(提取前先缩小两倍) xxx1=imresize(J2,2,'bicubic'); xxx2=imresize(xxx1,1/2,'bicubic'); yy=double(xxx2); end if attack_style==2 %%放大4倍操作(提取前先缩小4倍) xxx1=imresize(J2,4,'bicubic'); xxx2=imresize(xxx1,1/4,'bicubic'); yy=double(xxx2); end if attack_style==3 %%缩小1/4操作 xxx1=imresize(J2,3/4,'bicubic'); xxx2=imresize(xxx1,4/3,'bicubic'); yy=double(xxx2); end if attack_style==4 %% xxx1=imresize(J2,2/4,'bicubic'); xxx2=imresize(xxx1,4/2,'bicubic'); yy=double(xxx2); end %%3*3空域低通滤波 if attack_style==5 B=(1/9)*ones(3,3); xxx2=filter2(B,J2); yy=double(xxx2); end %%4领域平均 if attack_style==6 B=[0 1 0;1 0 1;0 1 0]*(1/4); xxx2=filter2(B,J2); yy=double(xxx2); end %%8领域平均 if attack_style==7 B=[1 1 1;1 0 1;1 1 1]*(1/8); xxx2=filter2(B,J2); yy=double(xxx2); end %%窗口中值滤波 if attack_style==8 xxx2=medfilt2(J2); %默认3*3 yy=double(xxx2); end if attack_style==9 % a1=input('Please input length of window a1:'); % b1=input('Please input length of window b1:'); a1=1; b1=3; xxx2=medfilt2(J2,[a1 b1]); save al al; save b1 b2; yy=double(xxx2); end %% 裁减 if attack_style==10 for i=128-44:128+45 for j=128-45:128+44 J2(i,j)=0; end end yy=double(J2); end if attack_style==11 for i=128-64:128+63 for j=128-64:128+63 J2(i,j)=0; end end yy=double(J2); end if attack_style==12 yy=imnoise(uint8(round(J2)),'gaussian',0,attack_strength); %高斯噪声 end if attack_style==13 imwrite(uint8(round(J2)),'jpeg_n.jpg','jpg','Quality',attack_strength); [yy,map]=imread('jpeg_n.jpg','jpg'); end if attack_style>13 yy=J2; end J3=blkproc(yy,[8 8],fun1); %%%%%%%%%%%%%%%%%%%%% 水印提取 %%%%%%%%%%%%%%%%% t1=zeros(L*MNm,1); t0=zeros(L*MNm,1); for i=1:M for k=1:N if fre(i,k)<=0.25&&block(i,k)<=L*MNm sy0(i,k)=round((J3(i,k)+d0(ceil(block(i,k)/L)))/step)*step-d0(ceil(block(i,k)/L)); sy1(i,k)=round((J3(i,k)+d1(ceil(block(i,k)/L)))/step)*step-d1(ceil(block(i,k)/L)); j=block(i,k); t1(j)=t1(j)+(J3(i,k)-sy1(i,k))^2; t0(j)=t0(j)+(J3(i,k)-sy0(i,k))^2; end end end %每块分别解码 for j=1:L*MNm if t0(j)-t1(j)>0 t(j)=255; else t(j)=0; end end %%每5块联合判决（观察即可） for j=1:MNm tt(j)=sum(t((j-1)*L+1:j*L)); end for j=1:MNm if tt(j)<(L/2)*255 m2(j)=0; else m2(j)=255; end end %%%%%%%%%%%%%% 计算误码率 %%%%%%%%%%%%%%%%%%%] err=sum(xor(m2,mm)); err=err/1024; mdd=reshape(m2,rowm,colm); figure(5),imshow(uint8(round(mdd))); title('提取的水印图像','Fontsize',8,'color','blue');