title: Parameters of detectMultiScale in OpenCV using Python
body: <p>I am not able to understand the parameters passed to detectMultiScale. I know that the general syntax is detectMultiScale(image, rejectLevels, levelWeights) 
  However, what do the parameters rejectLevels and levelWeights mean? And what are the optimal values used for detecting objects?</p>
  
  <p>I want to use this to detect pupil of the eye</p>