function?[wm]=exwmark（embimg）
%?exwmark?will?extract?the?watermark?which?were
%?embedded?by?the?wtmark?function

%?embimg????=?embedded?image
%?wt????????=?Extracted?Watermark
?
[row?clm]=size（embimg）;
m=embimg;

%%%%%%%%%%%%%%%%%?To?divide?image?in?to?4096---8X8?blocks?%%%%%%%%%%%%%%%%%%
k=1;?dr=0;?dc=0;
%?dr?is?to?address?1:8?row?every?time?for?new?block?in?x
%?dc?is?to?address?1:8?column?every?time?for?new?block?in?x
%?k?is?to?change?the?no.?of?cell
for?ii=1:8:row?%?To?address?row?--?8X8?blocks?of?image
????for?jj=1:8:clm?%?To?address?columns?--?8X8?blocks?of?image
????????for?i=ii:（ii+7）?%?To?address?rows?of?blocks
????????????dr=dr+1;
????????????for?j=jj:（jj+7）?%?To?address?columns?of?block
????????????????dc=dc+1;
????????????????z（drdc）=m（ij）;
????????????end
????????????dc=0;
????????end
????????x{k}=z;?k=k+1;
????????z=[];?dr=0;
????end
end
nn=x;

%%?Extract?water?mark?%%
wm=[];?wm1=[];?k=1;?wmwd=[];?wmwd1=[];
while（k<1025）
????for?i=1:32
????kx=x{k};?%?Extracting?Blocks?one?by?one
????dkx=blkproc（kx[8?8]@dct2）;?%?Applying?Dct
????nn{k}=dkx;?%?Save?DCT?values?in?new?block?to?cross?check
????
????%%?Change?me?for?pixel?location
????wm1=[wm1?dkx（88）];?%?Forming?a?row?of?32?by?88?element
???
????%?Extracting?water?mark?without?dct
?????wmwd1=[wmwd1?kx（88）];
??????k=k+1;
????end
????wm=[wm;wm1];?wm1=[];?%?Forming?columns?of?32x32
????wmwd=[wmwd;wmwd1];?wmwd1=[];
end

for?i=1:32
????for?j=1:32
????????diff=wm（ij）;?
????????if?diff?>=0
????????????wm（ij）=0;
????????elseif?diff?????????????wm（ij）=1;
????????end
????end
end

wm=wm‘;
imwrite（wm‘wex.jpg‘）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件??????29338??2014-06-05?10:06??基于matlab的水印篡改檢測的仿真\b.jpg

?????文件???????1660??2019-03-08?12:32??基于matlab的水印篡改檢測的仿真\exwmark.m

?????文件??????89421??2019-03-07?00:15??基于matlab的水印篡改檢測的仿真\main.fig

?????文件???????8332??2019-03-08?12:28??基于matlab的水印篡改檢測的仿真\main.m

?????文件??????39472??2019-04-20?19:15??基于matlab的水印篡改檢測的仿真\out.jpg

?????文件????????780??2014-06-05?10:06??基于matlab的水印篡改檢測的仿真\w.jpg

?????文件???????1007??2019-04-20?19:14??基于matlab的水印篡改檢測的仿真\wex.jpg

?????文件???????2745??2019-03-08?12:31??基于matlab的水印篡改檢測的仿真\wtmark.m

?????目錄??????????0??2019-04-20?19:14??基于matlab的水印篡改檢測的仿真

-----------?---------??----------?-----??----

???????????????172755????????????????????9