The SIFT (Scale Invariant Feature Transform) benchmark is derived from the code provided by Andrea Vedaldi at http://www.vlfeat.org/~vedaldi/code/sift.html, retrieved June 18, 2007. A later version of the component has been incorporated into the VLFeat open source package (http://VLFeat.org), 0.9.4.1.

The header files of the code contain the following license:  

/* AUTORIGHTS
Copyright (C) 2006 Regents of the University of California
All rights reserved

Written by Andrea Vedaldi (UCLA VisionLab).

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the University of California, Berkeley nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

In addition to the copyright terms mentioned above, the VLFeat.org webpage contains the following text:

  <p>This software program is Copyright &copy; 2006 The Regents of the
  University of California and can be freely used for academic purposes
  (see the included license file for details).  Although this
  implementation is original (in particular, it is <em>not</em> derived
  from <a shape="rect" href="http://www.cs.ubc.ca/~lowe/keypoints/">Lowe's
   implementation</a>), the SIFT algorithm has been issued a
  patent. Thus you should note that:</p>

 <blockquote style="font-style:italic;">
  This software embodies a method for which the following patent has
  been issued: &quot;Method and apparatus for identifying scale invariant
  features in an image and use of same for locating an object in an
  image,&quot; David G. Lowe, US Patent 6,711,293 (March 23,
  2004). Provisional application filed March 8, 1999. Asignee: The
  University of British Columbia.
 </blockquote>

We have modified SIFT in the following ways:

- we generated a standalone C version from the Matlab source files of SIFT.
- we augmented the code in order to support collection of benchmarking data (matlab and C)
- we create benchmark inputs for the code (matlab and C)
- we modified the code to use our own standardized library for common functions (matlab and C)

Our modifications are available under the same license as above, since UCSD is also
part of the University of California.