python opencv 视频的读取并且写图片

#1 样本 2 特征 3 分类器 4 检验
# haar + adaboost ..>>face
#haar模板特征 adaboost 三级(强分类器 弱分类器 node节点)
#hog模板特征 + SVM分类器
#数据的生成

#1 loard 2 info 3 parse 4 imshow imwrite
import numpy as np
import cv2
#1 获取视频打开句柄
cap = cv2.VideoCapture("F:\\a.mp4")
#2 判断
isOpened = cap.isOpened()
#3 获取帧率
fps = cap.get(cv2.CAP_PROP_FPS)
print("fps", fps)
#4 获取图片的宽度高度信息
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
print(fps, width, height)
i = 0
while(isOpened):
    # if i == 10:
    #     break
    # else:
    #     i = i +1
    (flag, frame) = cap.read()#读取每一张 flag frame
    fileName = 'F:\\PIC\\image'+str(i)+'.jpg'
    # print(fileName)
    if flag:
        cv2.imwrite(fileName, frame, [cv2.IMWRITE_JPEG_QUALITY, 100])
        # cv2.imshow("video", frame)
        # cv2.waitKey(50)
print("END!")