python: 'cv2.' -> 'cv.' via 'import cv2 as cv'

doc/py_tutorials/py_feature2d/py_brief/py_brief.markdown

@@ -52,16 +52,16 @@ detector is called STAR detector in OpenCV)
 note, that you need [opencv contrib](https://github.com/opencv/opencv_contrib)) to use this.
 @code{.py}
 import numpy as np
-import cv2
+import cv2 as cv
 from matplotlib import pyplot as plt
 
-img = cv2.imread('simple.jpg',0)
+img = cv.imread('simple.jpg',0)
 
 # Initiate FAST detector
-star = cv2.xfeatures2d.StarDetector_create()
+star = cv.xfeatures2d.StarDetector_create()
 
 # Initiate BRIEF extractor
-brief = cv2.xfeatures2d.BriefDescriptorExtractor_create()
+brief = cv.xfeatures2d.BriefDescriptorExtractor_create()
 
 # find the keypoints with STAR
 kp = star.detect(img,None)