text: import numpy as np
  import cv2
  
  IMAGES_FOLDER = "/Users/frank/Development/shoptrail/shoptrail-camera/images/"
  
  # Load an color image in grayscale
  cv2.namedWindow('image', cv2.WINDOW_NORMAL)
  img = cv2.imread(IMAGES_FOLDER + 'kollegen.jpg', 0)
  cv2.imshow('image',img)
  k = cv2.waitKey(0)
  if k == 27:         # wait for ESC key to exit
      cv2.destroyAllWindows()
  elif k == ord('s'): # wait for 's' key to save and exit
      cv2.imwrite(IMAGES_FOLDER + 'messigray.png',img)
      cv2.destroyAllWindows()
  