title: include nonfree openCV 2.4.10 on ubuntu
body: <p>I've installed OpenCV on ubuntu using this <a href="https://help.ubuntu.com/community/OpenCV" rel="noreferrer">link</a> and I'm trying to use SURF descriptor. I knew that they changed the location of these type of descriptors to the nonfree module so we need to include it, which is something like this: <code>#include "opencv2/nonfree/features2d.hpp"</code>. The problem is that I'm getting this error at compile time: <code>opencv2/nonfree/features2d.hpp no such file or directory.</code></p>
  
  <p>Any idea how to fix it?</p>
  
  <p><strong>EDITED:</strong>
  The other parts of openCV are working fine. I'm including the following libraries and everything is looking good:</p>
  
  <pre><code>#include "opencv2/core/core.hpp"
  #include "opencv2/features2d/features2d.hpp"
  #include "opencv2/highgui/highgui.hpp"
  #include "opencv2/calib3d/calib3d.hpp"
  #include "opencv2/legacy/legacy.hpp"
  </code></pre>
  
  <p>I checked the inlcude folder in my OpenCV directory and the nonfree folder is there. Moreover, it's the only library that I can't access within QTCreator (The environment I'm using) because I tried to include all the other librairies found in the Inlcude folder and they looked good.</p>
  
  <p><strong>EDITED2:</strong>
  You can see a screenshot of what I saw when I ran <code>make VERBOSE=1</code> on this <a href="https://www.dropbox.com/s/if1sabues125je4/3.png?dl=0" rel="noreferrer">link</a></p>
  
  <p>So not sure where to look? Actually, I did not find the nonfree folder in ../usr/include/opencv2/</p>
  
  <p>Thanks.</p>