detect low contrast image opencv code example

Example 1: feature to determine image too dark opencv

blur = cv2.blur(image, (5, 5))  # With kernel size depending upon image size
if cv2.mean(blur) > 127:  # The range for a pixel's value in grayscale is (0-255), 127 lies midway
    return 'light' # (127 - 255) denotes light image
else:
    return 'dark' # (0 - 127) denotes dark image

Example 2: python opencv check image read

import cv2 
import os.path

while not os.path.isfile("myImage.jpg"):
    #ignore if no such file is present.
    pass

img = cv2.imread("myImage.jpg", 0)

cv2.imwrite("result.jpg", img)