import cv2 
path = r'C:\Users\Rajnish\Desktop\geeksforgeeks\geeks.png'
image = cv2.imread(path, 0)
# represents the top left corner of rectangle
start_point = (100, 50)
# represents the bottom right corner of rectangle
end_point = (125, 80)
color = (0, 0, 0)
linethickness = -1
image = cv2.rectangle(image, start_point, end_point, color, linethickness)
cv2.imshow('Image', image)