Revision history [back]

do you really need the ellipse? or just the corners of the cross is sufficient?

warning: it has not been tested on other orientation

f1 = cv2.goodFeaturesToTrack (
            cv2.pyrDown(img), 3,
            0.95, 
            50.)*2.

features = cv2.goodFeaturesToTrack (
            img, 10,
            0.33, 
            50.)

for f in f1:
    cv2.circle(img, tuple(f[0]), 5, (255))

for f in features:
    cv2.circle(img, tuple(f[0]), 2, (255))