function[TZ]=Forstern（imgn）
[hw]=size（img）;
imgs=img;
figure（1）;
imshow（img[]）;
hold?on;
result=zeros（hw）;
Qq=zeros（hw）;
Nn=zeros（hw）;
gu?=?zeros?（hw）;
gv?=?zeros（hw）;
%?計算gugv
for?i=1:h-1
????for?j=1:w-1
????????gu（ij）=imgs（i+1j+1）-imgs（ij）;
????????gv（ij）=imgs（ij+1）-imgs（i+1j）;?
????end
end
%?5*5窗口計算協方差矩陣
z=2;
for?i?=?1+z:h-z
????for?j?=?1+z:w-z
????????gu_w=gu（i-z:i+zj-z:j+z）;
????????gv_w=gv（i-z:i+zj-z:j+z）;
????????gu2=gu_w.^2;
????????gv2=gv_w.^2;
????????sum_gu2=sum（gu2（:））;
????????sum_gv2=sum（gv2（:））;
????????guv=gu_w.*gv_w;
????????sum_guv=sum（guv（:））;
????????N=[gu2guv;guvgv2];
????????Q=-N;
????????q=4*det（N）/trace（N）^2;
????????omg=det（N）/trace（N）;
????????Qq（ij）=q;
????????Nn（ij）=omg;
????end
end
%?將值為NaN數組置零
Z=find（isnan（Qq））;
Qq（Z）=[0];
X=find（isnan（Nn））;
Nn（X）=[0];
Tq=0.75;
Tw=mean（Nn（:））;
%?獲取候選點
for?i?=?1+z:h-z
????for?j?=?1+z:w-z
????????if?Qq（ij）<=Tq&&Nn（ij）<=0.5*Tw
????????????Nn（ij）=0;
????????end
????end
end
%?選取特征點
k=1;
TZ=zeros（k2）;
for?i?=?1+n:h-n
????for?j?=?1+n:w-n
?????????????tempiv=Nn（i-n:i+nj-n:j+n）;
?????????????if?max（tempiv（:））==Nn（ij）&&max（tempiv（:））~=0
?????????????????TZ（k1）=i;
?????????????????TZ（k2）=j;
?????????????????k=k+1;
?????????????end
????end
end
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????1340??2018-06-22?17:07??F.m
?????文件??????584744??2018-06-21?22:59??left.tif
?????文件????????2391??2018-07-24?23:17??matching.m
?????文件??????560712??2018-06-21?23:46??right.tif