#!/usr/bin/env python2.7

import sys, math
import numpy as np
import cv2

def main(argv):

  if len(argv) == 2:
    # load a color image
    #img = cv2.imread(argv[1])
    # load a color image as grayscale
    img = cv2.imread(argv[1],0)
  
    # display
    cv2.imshow('image',img)
  
    # wait for key input
    k = cv2.waitKey(0)
    if k == 27:
      # wait for ESC key
      cv2.destroyAllWindows()
      # wait for 's' key to save and exit
    elif k == ord('s'):
      cv2.imwrite('DR400Markers_g.jpg',img)
      cv2.destroyAllWindows()
  else:
    print("Usage: ", argv[0], " <img>")
    sys.exit()

if __name__ == '__main__':
# main(sys.argv[1:])
  main(sys.argv)