import numpy as np
import cv2

img = cv2.imread('cornerR.png')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
gray = np.float32(gray)

corners = cv2.goodFeaturesToTrack(gray, 800, 0.01, 0.5)
corners = np.int0(corners)

for corner in corners:
    x,y = corner.ravel()
    cv2.circle(img, (x,y), 3, (0, 0, 255), -1)
    
cv2.imshow('CornerUgao', img)

