import sys
import cv2 as cv

def test():
 src = cv.imread("/home/sc/disk/keepgoing/opencv_test/lights.jpeg") 
 top = int(0.05 * src.shape[0]) # shape[0] = rows
 bottom = top
 left = int(0.04 * src.shape[1]) # shape[1] = cols
 right = left
 
 value = [0,0,0]
 borderType = cv.BORDER_CONSTANT
 dst1 = cv.copyMakeBorder(src, top, bottom, left, right, borderType, None, value)
 
 borderType = cv.BORDER_REPLICATE
 dst2 = cv.copyMakeBorder(src, top, bottom, left, right, borderType, None, value)
 
 cv.imshow("blackborder",dst1)
 cv.imshow("BORDER_REPLICATE",dst2)
 
 if 27 == cv.waitKey():
  cv.destroyAllWindows()
  
test()