function?descriptors?=?do_descriptor（octave?oframes??sigma0?Ssminvarargin）

for?k=1:2:length（varargin）
	switch?lower（varargin{k}）
??????case?‘magnif‘
????????magnif?=?varargin{k+1}?;??????
??????case?‘numspatialbins‘
????????NBP?=?varargin{k+1}?;???????
??????case??‘numorientbins‘
????????NBO?=?varargin{k+1}?;???
??????otherwise
????????error（[‘Unknown?parameter?‘?varargin{k}?‘.‘]）?;
?????end
end?
???????????????????????????????????
num_spacialBins?=?NBP;
num_orientBins?=?NBO;
key_num?=?size（oframes?2）;
%?計算圖像梯度?
[M?N?s_num]?=?size（octave）;?
descriptors?=?[];
magnitudes?=?zeros（M?N?s_num）;
angles?=?zeros（M?N?s_num）;

for?si?=?1:?s_num
????img?=?octave（::si）;
????dx_filter?=?[-0.5?0?0.5];
????dy_filter?=?dx_filter‘;
????gradient_x?=?imfilter（img?dx_filter）;
????gradient_y?=?i

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1181??2010-05-20?12:41??新建文件夾\do_localmax.m

?????文件???????3278??2010-05-20?12:51??新建文件夾\do_extrefine.m

?????文件???????1753??2010-05-20?12:57??新建文件夾\do_orientation.m

?????文件???????4156??2010-05-20?13:02??新建文件夾\do_descriptor.m

?????文件???????2365??2010-05-20?12:30??新建文件夾\do_gaussian.m

?????文件????????323??2010-05-20?12:30??新建文件夾\do_diffofg.m

?????文件???????2423??2010-05-23?13:34??新建文件夾\do_sift.m

?????文件????????101??2010-05-21?10:53??新建文件夾\smooth.m

?????文件?????842240??2010-05-23?13:36??新建文件夾\片段.shs

?????目錄??????????0??2010-05-23?13:33??新建文件夾

-----------?---------??----------?-----??----

???????????????857820????????????????????10