import?numpy?as?np??
import?cv2??
??
cap?=?cv2.VideoCapture（‘slow.flv‘）??
??
#?params?for?ShiTomasi?corner?detection??
feature_params?=?dict（?maxCorners?=?100??
???????????????????????qualityLevel?=?0.3??
???????????????????????minDistance?=?7??
???????????????????????blockSize?=?7?）??
??
#?Parameters?for?lucas?kanade?optical?flow??
lk_params?=?dict（?winSize??=?（1515）??
??????????????????maxLevel?=?2??
??????????????????criteria?=?（cv2.TERM_CRITERIA_EPS?|?cv2.TERM_CRITERIA_COUNT?10?0.03））??
??
#?Create?some?random?colors??
color?=?np.random.randint（0255（1003））??
??
#?Take?first?frame?and?find?corners?in?it??
ret?old_frame?=?cap.read（）??
old_gray?=?cv2.cvtColor（old_frame?cv2.COLOR_BGR2GRAY）??
p0?=?cv2.goodFeaturesToTrack（old_gray?mask?=?None?**feature_params）??
??
#?Create?a?mask?image?for?drawing?purposes??
mask?=?np.zeros_like（old_frame）??
??
while（1）: