opencv提取颜色做追踪

import cv2
import numpy as np
# flags = [i for i in dir(cv2) if i stratswith('COLOR_')]
# print flags

cap = cv2.VideoCapture(0)

while(1):
    ret,frame=cap.read()

    hsv=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)

    lower_blue=np.array([110,50,50])
    upper_blue=np.array([130,250,250])

    mask=cv2.inRange(hsv,lower_blue,upper_blue)

    res=cv2.bitwise_and(frame,frame,mask=mask)

    cv2.imshow('frame',frame)
    cv2.imshow('mask',mask)
    cv2.imshow('res',res)
    k=cv2.waitKey(5)&0xFF
    if k==27:
        break
cv2.destroyAllWindows()