import cv2 as cv
import numpy as np

img = cv.imread('/home/arpitjain/Desktop/Code/Python/OpenCV/pictures/day.jpg')
# cv.imshow('image', img)

blank = np.zeros(img.shape[0:2], dtype='uint8')

mask = cv.circle(blank, (img.shape[1]//2,img.shape[0]//2),150, 255, -1)
# cv.imshow('mask', mask)

masked = cv.bitwise_and(img, img, mask=mask)
cv.imshow('masked', masked)


cv.waitKey(0)