python摄像头读取图片并保存为图片帧格式

import cv2import timecap = cv2.VideoCapture(0)width = 1280  #定义摄像头获取图像宽度heightht = 720   #定义摄像头获取图像长度capp.set(6, cv2.VideoWriter_fourcc('M','J','P','G'))# cap视频流格式.set(5, 10)# 帧率cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)  #设置宽度cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)  #设置长度while True:    ret, frame = cap.read()    if ret:        now = time.perf_counter()        print(cap.get(cv2.CAP_PROP_FPS))# 得到帧率        cv2.imshow('frame',frame)        cv2.waitKey(1)        end = time.perf_counter()        print('total time:%s'%(end-now))# 打印每个循环所需的时间    else:        print(‘摄像头未打开’)