Matlab编程实现LSB信息的隐藏与提取

2010.111，，、。MatlabMATHWORKS，，，。—LSB（）。，。，，，。2LSB，。1，mod21；0，mod20。LSB。mod21，1；mod20，0。，，，。：LSB，。：for(i=1；i=；i++）Si←Ci//Ci，Si//endforfor(i=1；i=；i++)Sji←Cji←Mi//MiSjiendfor：for(i=1；i=；i++)i←→ji//ijiMi←LSB(Cji)//CjiLSB，endfor：，，。：for(i=1；i=；i++）Si←Ci//Ci，Si//endforn←k1//kkifor(i=1；i=；i++)Sn←Cn←Min←n+kiendfor：n←k1//kkifor(i=1；i=；i++)Mi←LSB(Cn)//KKi//，n←n+kiendfor3MatlabLSB3.13．1．1Picture=imread(‘c:\\test.tif’);%Double_Picture=Picture;Double_Picture=double(Double_Picture);%‘c:\\test.txt’_id=fopen(‘c:\\test.txt’,'r');%[msg,len]=fread(‘c:\\test.txt’_id,'ubit1');[m,n]=size(Double_Picture);MatlabLSB：。MatlabLSB（），MatlabLSB。：Matlab；；LSB762010.11p=1;%pforf2=1:nforf1=1:mDouble_Picture(f1,f2)=Double_Picture(f1,f2)-mod(Dou-ble_Picture(f1,f2),2)+msg(p,1);%ifp==lenbreak;endp=p+1;endifp==lenbreak;endendDouble_Picture=uint8(Double_Picture);imwrite(Double_Picture,‘c:\\result.tif’);%subplot(121);imshow(Picture);title('');subplot(122);imshow(Double_Picture);title('');1。3．1．2Picture=imread(‘c:\\result.tif’);%Picture=double(Picture);[m,n]=size(Picture);frr=fopen(‘c:\\result.txt’,'a');len=8;%p=1;forf2=1:nforf1=1:mifbitand(Picture(f1,f2),1)==1%LSBfwrite(frr,1,'bit1');result(p,1)=1;elsefwrite(frr,0,'bit1');result(p,1)=0;endifp==len%break;endp=p+1;endifp==lenbreak;endendfclose(frr);2。3．23．2．1Picture=imread(‘c:\\test.tif’);%Double_Picture=Picture;Double_Picture=double(Double_Picture);%‘c:\\test.txt’_id=fopen(‘c:\\test.txt’,'r');[msg,msg_len]=fread(‘c:\\test.txt’_id,'ubit1');[m,n]=size(Picture);p=1;%p[row,col]=randinterval(Double_Picture,msg_len,2010);%2010，fori=1:msg_lenDouble_Picture(row(i),col(i))=Double_Picture(row(i),col(i))-mod(Double_Picture(row(i),col(i)),2)+msg(p,1);%LSBifp==msg_lenbreak;endp=p+1;endDouble_Picture=uint8(Double_Picture);imwrite(Double_Picture,‘c:\\result.tif’);%subplot(121);imshow(Picture);title('');subplot(122);imshow(Double_Picture);title('');3。772010.113.2.2Picture=imread(‘c:\\result.tif’);%Picture=double(Picture);[m,n]=size(Picture);frr=fopen(‘c:\\result.txt’,'a');msg_len=8;p=1;%p[row,col]=randinterval(Picture,msg_len,2010);%%fori=1:msg_lenifbitand(Picture(row(i),col(i)),1)==1%，%LSB，fwrite(frr,1,'bit1');result(p,1)=1;elsefwrite(frr,0,'bit1');result(p,1)=0;endifp==msg_lenbreak;endp=p+1;endfclose(frr);4。4，，，LSB，。，，1KB，5。，LSB（），，，。，6。6，，，。5MatlabLSB，，，，，。。LSB，，，。78