title: AttributeError: 'module' object has no attribute 'xfeatures2d' [Python/OpenCV 2.4]
body: <p>This line:</p>
  
  <pre><code>sift = cv2.xfeatures2d.SIFT_create()
  </code></pre>
  
  <p>return error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:/Python27/openCVskrypty/GUI/SOLUTION2.py", line 11, in &lt;module&gt;
      sift = cv2.xfeatures2d.SIFT_create()
  AttributeError: 'module' object has no attribute 'xfeatures2d'
  </code></pre>
  
  <p>I read something about this error and it appears in OpenCV version 3.0. 
  This is quite weird because I have 2.4.11 version. </p>
  
  <p>I check dir(cv2) and I haven't got xfeatures2d module. Does anyone know why? Can I download it separately? </p>
  
  <p>Thanks for help how fix this.</p>