title: OpenCV Python unsupported array type error
body: <p>I am new to Python (but not new to openCV) and I am pretty sure everything is installed correctly, I have tested some programs and the seem to work fine, but when ever I want to draw on an image, for example this code taken from a Python openCV tutorial : </p>
  
  <pre><code>import numpy as np
  import cv2
  # Create a black image
  img = np.zeros((512,512,3), np.uint8)
  # Draw a diagonal blue line with thickness of 5 px
  img = cv2.line(img,(0,0),(511,511),(255,0,0),5)
  cv2.imshow('img',img)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  </code></pre>
  
  <p>I get this following error:</p>
  
  <pre><code>OpenCV Error: Bad flag (parameter or structure field) (Unrecognized or unsupported array type) in cvGetMat, file /build/buildd/opencv-2.3.1/modules/core/src/array.cpp, line 2482
  Traceback (most recent call last):
  File "/home/dccv/rec 2.py", line 17, in &lt;module&gt;
  cv2.imshow('img',img)
  cv2.error: /build/buildd/opencv-2.3.1/modules/core/src/array.cpp:2482: error: (-206)
  Unrecognized or unsupported array type in function cvGetMat
  </code></pre>
  
  <p>any help would be appreciated, I get the same error on both windows and ubuntu.  </p>