import numpy as np import cv2
img = cv2.imread('C:\\Users\\mlarn\\Downloads\\20170818_171339.jpg',0)
#cv2.namedWindow('C:\\Users\\mlarn\\Downloads\\20170818_171339.jpg', cv2.WINDOW_NORMAL)
cv2.imshow('C:\\Users\\mlarn\\Downloads\\20170818_171339.jpg',0)
cv2.waitKey(0) & 0xFF
cv2.destroyAllWindows()
Just opens a window like this 
If I uncomment the WINDOW_NORMAL flag and resize the window, it is just black. 
I've tried it on multiple files of differing types and get the same result.
What am I doing wrong?