title: How do I convert an RGB picture into graysacle using simplecv?
body: <p>So working with windows, python 2.7 and simplecv I am making a live video with my webcam and want simplecv to give me a grayscale version of the video. Is there any simple way to achieve that? 
  I found the command </p>
  
  <pre><code>grayscale()
  </code></pre>
  
  <p>on the opencv page, which should do exactly that but when I run it I get the error:</p>
  
  <pre><code>NameError: name "grayscale" is not defined
  </code></pre>
  
  <p>I am currently using this prewritten code for object tracking but I don't know whether I should use the command I found, and where in the code I should put it, does anybody have an idea? :</p>
  
  <pre><code>print __doc__
  
  import SimpleCV
  
  display = SimpleCV.Display()
  cam = SimpleCV.Camera()
  normaldisplay = True
  
  while display.isNotDone():
  
        if display.mouseRight:
            normaldisplay = not(normaldisplay)
            print "Display Mode:", "Normal" if normaldisplay else "Segmented" 
  
        img = cam.getImage().flipHorizontal()
        dist = img.colorDistance(SimpleCV.Color.BLACK).dilate(2)
        segmented = dist.stretch(200,255)
        blobs = segmented.findBlobs()
        if blobs:
           circles = blobs.filter([b.isCircle(0.2) for b in blobs])
           if circles:
               img.drawCircle((circles[-1].x, circles[-1].y), circles[-1].radius(),SimpleCV.Color.BLUE,3)
  
  if normaldisplay:
      img.show() 
  else:
      segmented.show()
  </code></pre>