function?[output]=NLmeansfilter（inputtfh）
?
?%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
?%
?%??input:?image?to?be?filtered
?%??t:?radio?of?search?window
?%??f:?radio?of?similarity?window
?%??h:?degree?of?filtering
?%
?%??Author:?Jose?Vicente?Manjon?Herrera?&?Antoni?Buades
?%??Date:?09-03-2006
?%
?%??Implementation?of?the?Non?local?filter?proposed?for?A.?Buades?B.?Coll?and?J.M.?Morel?in
?%??“A?non-local?algorithm?for?image?denoising“
?%
?%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

?%?Size?of?the?image
?[m?n]=size（input）;
?
?
?%?Memory?for?the?output
?Output=zeros（mn）;

?%?Replicate?the?boundaries?of?the?input?image
?input2?=?padarray（input[f?f]‘symmetric‘）;
?
?%?Used?kernel
?kernel?=?make_kernel（f）;
?
?kernel?=?kernel?/?sum（sum（kernel））;
?
?
?for?i=1:m
?????for?j=1:n
?????????????????
?????????i1?=?i+?f;
?????????j1?=?j+?f;
????????
?????????
?????????W1=?input2（i1-f:i1+f??j1-f:j1+f）;
?????????
?????????wmax=0;?
?????????average=0;
?????????sweight=0;
?????????
?????????rmin?=?max（i1-tf+1）;
?????????rmax?=?min（i1+tm+f）;
?????????smin?=?max（j1-tf+1）;
?????????smax?=?min（j1+tn+f）;
?????????
?????????for?r=rmin:1:rmax
?????????????for?s=smin:1:smax
??????????????????????????????
?????????????????
?????????????????if（r==i1?&&?s==j1）?continue;?end;
????????????????
?????????????????
?????????????????W2=?input2（r-f:r+f??s-f:s+f）;????????????????
?????????????????
?????????????????d?=?sum（sum（kernel.*（W1-W2）.*（W1-W2）））;
??????????????????????????????
?????????????????
?????????????????w=exp（-d/h）;
?????????????????
?????????????????????????????????
?????????????????if?w>wmax
????????????????
????????????????????wmax=w;
???????????????????
????????????????end
????????????????
????????????????sweight?=?sweight?+?w;
????????????????average?=?average?+?w*input2（rs）;
??????????????????????????????????
?????????????end
?
?????????end
?????????????
????????average?=?average?+?wmax*input2（i1j1）;
????????sweight?=?sweight?+?wmax;
????????
???????????
????????if?sweight?>?0
????????????output（ij）?=?average?/?sweight;
????????else
????????????output（ij）?=?input（ij）;
????????end
????????
????????
?????end
?end
?
?
????
?
?function?[kernel]?=?make_kernel（f）
????????
????????
?
????kernel=zeros（2*f+12*f+1）;

????for?d=1:f
????
????????value=?1?/?（2*d+1）^2?;
????
????????for?i=-d:d
????????????for?j=-d:d
????????????????kernel（f+1-if+1-j）=?kernel（f+1-if+1-j）?+?value?;
????????end
????end
end


kernel?=?kernel?./?f

????????

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????2623??2007-09-15?00:51??NLmeansfilter.m