function?[fx?fy?ft]?=?computeDerivatives（im1?im2）

if?size（im21）==0
????im2=zeros（size（im1））;
end

%?Horn-Schunck?original?method
fx?=?conv2（im10.25*?[-1?1;?-1?1]‘same‘）?+?conv2（im2?0.25*[-1?1;?-1?1]‘same‘）;
fy?=?conv2（im1?0.25*[-1?-1;?1?1]?‘same‘）?+?conv2（im2?0.25*[-1?-1;?1?1]?‘same‘）;
ft?=?conv2（im1?0.25*ones（2）‘same‘）?+?conv2（im2?-0.25*ones（2）‘same‘）;

%?derivatives?as?in?Barron
%?fx=?conv2（im1（1/12）*[-1?8?0?-8?1]‘same‘）;
%?fy=?conv2（im1（1/12）*[-1?8?0?-8?1]‘‘same‘）;
%?ft?=?conv2（im1?0.25*ones（2）‘same‘）?+?conv2（im2?-0.25*ones（2）‘same‘）;
%?fx=-fx;fy=-fy;

%?An?alternative?way?to?compute?the?spatiotemporal?derivatives?is?to?use?simple?finite?difference?masks.
%?fx?=?conv2（im1[1?-1]）;
%?fy?=?conv2（im1[1;?-1]）;
%?ft=?im2-im1;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2013-06-20?10:45??HS\
?????文件????????2756??2009-01-22?13:08??HS\HS.m
?????文件??????236079??2009-01-22?13:14??HS\HSsnapshot.JPG
?????文件?????????759??2009-01-05?18:05??HS\computeDerivatives.m
?????文件????????1081??2009-01-22?13:04??HS\gaussFilter.m
?????文件????????1383??2009-01-22?12:46??HS\plotFlow.m
?????文件?????????944??2009-01-22?13:04??HS\smoothImg.m
?????文件???????78886??2008-03-03?11:56??HS\yos10.tif
?????文件???????78908??2008-03-03?11:56??HS\yos9.tif