opencv 跟踪黑色区域， 摄像头读取

import cv2import numpy as np cap = cv2.VideoCapture(0)  # 或传入0，使用摄像头 while(True):     # 读取一帧    _, frame = cap.read()     # 把 BGR 转为 HSV    hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)     # HSV中黑色范围    lower_blue = np.array([0,0,0])     upper_blue = np.array([180,255,46])      # 获得黑色区域的mask    mask = cv2.inRange(hsv, lower_blue, upper_blue)     # 和原始图片进行and操作，获得黑色区域    res = cv2.bitwise_and(frame,frame, mask= mask)     cv2.namedWindow('frame', cv2.WINDOW_NORMAL)    cv2.imshow('frame',frame)    cv2.namedWindow('mask', cv2.WINDOW_NORMAL)    cv2.imshow('mask',mask)    cv2.namedWindow('res', cv2.WINDOW_NORMAL)    cv2.imshow('res',res)     k = cv2.waitKey(5) & 0xFF    if k == 27:        break cv2.destroyAllWindows() 

import numpy as npimport cv2cap = cv2.VideoCapture(0)while(cap.isOpened()):  # check !    # capture frame-by-frame    ret, frame = cap.read()    if ret: # check ! (some webcam's need a "warmup")        # our operation on frame come here        gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)        # Display the resulting frame        cv2.imshow('frame', gray)    if cv2.waitKey(1) & 0xFF == ord('q'):        break# When everything is done release the capturecap.release()cv2.destroyAllWindows()