%Frost?filter?for?speckle?noise?reduction
%Author?:?Jeny?Rajan
function?[ft]=frost（I）
%?I?is?the?noisy?input?image
tic
[x?y?z]=size（I）;
I=double（I）;
K=1;
N=I;
for?i=1:x
????for?j=1:y??????????????????????????????
????????if?（i>1?&?i1?&?j????????????mat（1）=I（i-1j）;
????????????mat（2）=I（i+1j）;
????????????mat（3）=I（ij-1）;
????????????mat（4）=I（ij+1）;
????????????d（1）=sqrt（（i-（i-1））^2）;
????????????d（2）=sqrt（（i-（i+1））^2）;
????????????d（3）=sqrt（（j-（j-1））^2）;
????????????d（4）=sqrt（（j-（j+1））^2）;
????????????mn=mean（mean（mat））;
????????????c=mat-mn;
????????????c2=c.^2;
????????????c3=c/（c2+.0000001）;
????????????Cs=0.25*sum（sum（c3））;
????????????m（1）=exp（-K*Cs*d（1））;
????????????m（2）=exp（-K*Cs*d（2））;
????????????m（3）=exp（-K*Cs*d（3））;
????????????m（4）=exp（-K*Cs*d（4））;
????????????ms=sum（sum（m））;
????????????mp=m/ms;
????????????N（ij）=sum（sum（mp.*mat））;????????????????????
????????end
?????end
end
toc
ft=uint8（N）;

?屬性????????????大小?????日期????時間???名稱
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?????文件????????969??2009-03-31?08:01??frost.m

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??????????????????969????????????????????1