import cv2
import numpy as np
import copy

img = cv2.imread('box.jpg')
img_orig = copy.copy(img)
grayimg = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

corners = cv2.goodFeaturesToTrack(grayimg,10,0.05,25)
corners = np.float32(corners)

for item in corners:
	x,y = item[0]
	cv2.circle(img,(x,y),5,255,-1)

cv2.imshow("Original",img_orig)
cv2.imshow("Top 10 corners",img)
if cv2.waitKey(0) & 0xff == 27:
    cv2.destroyAllWindows()