title: Python Opencv - Find black dots inside contours
body: <p>I'm using the python wrapper for OpenCV 2.1. (I can't use any external library)</p>
  
  <p>Does anyone know how can I find a black dot put inside other 2 concentric black shapes?
  Now I'm using cv.FindCountours to detect the black areas, but then I don't know how to discard the 2 concentric shapes and keep only the internal dot</p>
  
  <p>link to image: <a href="http://img848.imageshack.us/img848/2797/visiodrawing11.png" rel="nofollow">http://img848.imageshack.us/img848/2797/visiodrawing11.png</a></p>