VL_SIFT.html">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 DETAILS ON THE GEOMETRY
</p><p>
As mentioned, the <a href="VL_DSIFT.html">VL_DSIFT</a>() descriptors cover the bounding box
specified by BOUNDS = [XMIN YMIN XMAX YMAX]. Thus the top-left bin
of the top-lef