title: What constants (codes) are available in opencv
body: <p>When calling Opencv function, usually a constant is provided to function call, like:</p>
  
  <pre><code>im_hsv = cv2.cvtColor(im, cv2.COLOR_BGR2HSV)
  </code></pre>
  
  <p>while I can't find reference to all available constants. Opencv distribution download (~250MB) doesn't contain <code>constants.h</code> file.</p>
  
  <p>Google shows this pointer: <a href="https://code.ros.org/trac/opencv/browser/trunk/opencv/interfaces/swig/filtered/constants.h?rev=277" rel="nofollow">https://code.ros.org/trac/opencv/browser/trunk/opencv/interfaces/swig/filtered/constants.h?rev=277</a> which is deprecated as 8 years old.  </p>
  
  <p>In Opencv project at Github , there doesn't seem to be such file also, so does anyone have a link to a file that contains all available Opencv constants?</p>