Update kalibr_camera_focus

solves ethz-asl#247

aslam_offline_calibration/kalibr/python/kalibr_camera_focus

@@ -2,7 +2,6 @@
 print "importing libraries"
 import rospy
 import cv2
-import cv
 import numpy as np
 from sensor_msgs.msg import Image
 from cv_bridge import CvBridge, CvBridgeError
@@ -12,7 +11,6 @@ class CameraFocus:
     def __init__(self, topic):
         self.topic = topic
         self.windowNameOrig = "Camera: {0}".format(self.topic)
-        cv2.namedWindow(self.windowNameOrig, 2)
         self.bridge = CvBridge()
         self.image_sub = rospy.Subscriber(self.topic, Image, self.callback)
 
@@ -58,4 +56,4 @@ if __name__ == "__main__":
     except KeyboardInterrupt:
         print "Shutting down" 
 
-    cv.DestroyAllWindows()
+    cv2.DestroyAllWindows()