--- a/python/cvutils.py	Fri Jun 05 13:26:51 2015 +0200
+++ b/python/cvutils.py	Fri Jun 05 17:13:28 2015 +0200
@@ -126,7 +126,8 @@
     def playVideo(filename, firstFrameNum = 0, frameRate = -1, interactive = False, printFrames = True, text = None, rescale = 1., step = 1):
         '''Plays the video'''
         windowName = 'frame'
-        cv2.namedWindow(windowName, cv2.WINDOW_NORMAL)
+        if rescale == 1.:
+            cv2.namedWindow(windowName, cv2.WINDOW_NORMAL)
         wait = 5
         if frameRate > 0:
             wait = int(round(1000./frameRate))
@@ -259,7 +260,7 @@
         if yCropMax != yCropMin and xCropMax != xCropMin and (yCropMax - yCropMin) * (xCropMax - xCropMin) > minNPixels:
             croppedImg = img[yCropMin : yCropMax, xCropMin : xCropMax]
         else:
-            croppedImg = []
+            croppedImg = None
         return croppedImg, yCropMin, yCropMax, xCropMin, xCropMax
 
 
@@ -273,7 +274,8 @@
         height = int(capture.get(cv2.cv.CV_CAP_PROP_FRAME_HEIGHT))
 
         windowName = 'frame'
-        #cv2.namedWindow(windowName, cv2.WINDOW_NORMAL)
+        if rescale == 1.:
+            cv2.namedWindow(windowName, cv2.WINDOW_NORMAL)
 
         if undistort: # setup undistortion
             [map1, map2] = computeUndistortMaps(width, height, undistortedImageMultiplication, intrinsicCameraMatrix, distortionCoefficients)