title: cannot locate haarcascade default frontal face XML file on windows
body: <p>I am new to image processing and i've been getting my hands dirty with opencv for python for past few weeks. Today I tried to use the default haarcascade XML file for the face detection. Here is my code:</p>
  
  <pre><code>import cv2
  import numpy as np
  
  front_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
  
  img = cv2.imread('lena.jpg')
  gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
  
  faces = front_cascade.detectMultiScale(gray, 1.3, 6)
  #for (x, y, w, h) in faces:
  #    cv2.rectangle(img, (x, y), (x + w, y + h), (0, 255, 155), 3)
  
  print faces
  
  cv2.imshow('frame', img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>
  
  <p>Problem here is that it prints out an empty set. And to my surprise when I change the name of the XML file to something like 'aaa.xml', it still produces the same output. Any help would be highly appreciated.</p>