ize) ;
 f(3,:) = binSize/magnif ;
 f(4,:) = 0 ;
 [f_, d_] = vl_sift(I, 'frames', f) ;
</pre></dd><dt>
Remark
</dt><dd><p>
The equivalence is never exact due to (i) boundary effects
and (ii) the fact that <a href="%pathto:vl_sift;">VL_SIFT</a>() downsamples the image to save
computation. It is, however, usually very good.
</p></dd><dt>
Remark
</dt><dd><p>
In categorization it is often useful to under-smooth the image,
comared to standard SIFT, in order to keep the gradients
sharp.
</p></dd></dl><p>
FURTHER D