text: import cv2
  import numpy as np
  
  img = cv2.imread("/home/python/Desktop/opencv_test/opencv_test1/card_1.jpg")
  img = cv2.GaussianBlur(img, (3, 3), 0)
  img1 = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
  ret, img_thresh = cv2.threshold(img1, 0, 255, cv2.THRESH_OTSU)
  
  cv2.imshow("img_thresh", img_thresh)
  cv2.waitKey(0)
  cv2.destroyAllWindows()
  