OpenCV将视频转存为一帧帧的图片(Python)

利用OpenCV将视频逐帧保存，代码如下。

#coding=utf-8
import cv2
import os

path = 'video'
video_list = os.listdir(path)
for video in video_list:
    video_path = os.path.join(os.getcwd(),path,video)
    vc=cv2.VideoCapture(video_path)
    if vc.isOpened():
        rval,frame=vc.read()
    else:
        rval=False

    c =1
    while rval:
        rval,frame=vc.read()
        if rval==False:
        	break
        cv2.imwrite('./video2img/'+str(video)+str(c)+'.jpg',frame)
        print(c)
        c=c+1
        cv2.waitKey(1)
    vc.release()

不过，将视频逐帧保存，可能会图片信息冗余的问题，毕竟一秒保存几十帧图片，难免图片重复。
以下代码是每隔30帧保存一张图片，基本算是一秒保存一帧了。

#coding=utf-8
import cv2
import os

path = 'video'
video_list = os.listdir(path)
for video in video_list:
    video_path = os.path.join(os.getcwd(),path,video)
    vc=cv2.VideoCapture(video_path)
    if vc.isOpened():
        rval,frame=vc.read()
    else:
        rval=False

    c =1
    i = 0
    Num_Threshold = 30
    while rval:
        rval,frame=vc.read()
        i += 1
        if i % Num_Threshold==0:
            cv2.imwrite('./video2img/'+str(video)+str(c)+'.jpg',frame)
            i = 0
        print(c)
        c=c+1
        cv2.waitKey(1)
    vc.release()