title: Open CV Python Face Detection
body: <p>I am looking it to using haar cascades for face detection, so I tried following the tutorial here:
  <a href="http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_objdetect/py_face_detection/py_face_detection.html" rel="nofollow">http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_objdetect/py_face_detection/py_face_detection.html</a></p>
  
  <p>When I run it though, the image window populates, but the rectangles are not drawn. I checked over the code and everything makes sense to me or if maybe I was using a function that was obsolete, but everything seemed alright.</p>
  
  <p>I am not sure why I cannot get this working. Any suggestions as to what might be wrong?
  I am using Python 2.7.3.</p>
  
  <pre><code>import numpy as np
  import cv2
  
  face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
  eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
  
  img = cv2.imread('searchin2.jpg')
  gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
  
  faces = face_cascade.detectMultiScale(gray, 1.3, 5)
  
  for (x,y,w,h) in faces:
      cv2.Rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
      roi_gray = gray[y:y+h, x:x+w]
      roi_color = img[y:y+h, x:x+w]
      eyes = eye_cascade.detectMultiScale(roi_gray)
      for(ex,ey,ew,eh) in eyes:
          cv2.Rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2)
  
  cv2.imshow('img',img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>