th one
descriptor per column, in the same format of <a href="VL_SIFT.html">VL_SIFT</a>().
</p><p>
<a href="VL_DSIFT.html">VL_DSIFT</a>() does NOT compute a Gaussian scale space of the image
I. Instead, the image should be pre-smoothed at the desired scale
level, e.b. by using the <a href="VL_IMSMOOTH.html">VL_IMSMOOTH</a>() function.
</p><p>
The scale of the extracted descriptors is controlled by the option
SIZE, i.e. the width in pixels of a spatial bin (recall that a
SIFT descriptor is a spatial 