function?imDst?=?boxfilter（imSrc?r）


%???BOXFILTER???O（1）?time?box?filtering?using?cumulative?sum
%
%???-?Definition?imDst（x?y）=sum（sum（imSrc（x-r:x+ry-r:y+r）））;
%???-?Running?time?independent?of?r;?
%???-?Equivalent?to?the?function:?colfilt（imSrc?[2*r+1?2*r+1]?‘sliding‘?@sum）;
%???-?But?much?faster.


[hei?wid]?=?size（imSrc）;
imDst?=?zeros（size（imSrc））;


%cumulative?sum?over?Y?axis
imCum?=?cumsum（imSrc?1）;
%difference?over?Y?axis
imDst（1:r+1?:）?=?imCum（1+r:2*r+1?:）;
imDst（r+2:hei-r?:）?=?imCum（2*r+2:hei?:）?-?imCum（1:hei-2*r-1?:）;
imDst（hei-r+1:hei?:）?=?repmat（imCum（hei?:）?[r?1]）?-?imCum（hei-2*r:hei-r-1?:）;


%cumulative?sum?over?X?axis
imCum?=?cumsum（imDst?2）;
%difference?over?Y?axis
imDst（:?1:r+1）?=?imCum（:?1+r:2*r+1）;
imDst（:?r+2:wid-r）?=?imCum（:?2*r+2:wid）?-?imCum（:?1:wid-2*r-1）;
imDst（:?wid-r+1:wid）?=?repmat（imCum（:?wid）?[1?r]）?-?imCum（:?wid-2*r:wid-r-1）;
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-10-23?11:19??fog_off_matlab\
?????文件???????60238??2013-04-10?12:49??fog_off_matlab\18.jpg
?????文件?????????935??2017-10-23?10:53??fog_off_matlab\boxfilter.m
?????文件?????????969??2017-10-23?10:53??fog_off_matlab\guidedfilter.m
?????文件????????1849??2002-02-10?07:29??fog_off_matlab\maxfilt2.m
?????文件????????1849??2002-02-10?07:29??fog_off_matlab\minfilt2.m
?????文件????????1231??2017-10-23?11:10??fog_off_matlab\test.m
?????文件????????4841??2002-02-12?14:12??fog_off_matlab\vanherk.m