从一段视频中按帧提取图片

这里实现的是从一段视频中每10帧读取第10帧图片，代码如下：

# -*- coding:utf-8 -*-
#视频中按序列提取帧，获得训练数据
import cv2
import os

video_src_path = "D:/mtcnn"
video_save_path = "D:/mtcnn/mydata"

videos = os.listdir(video_src_path)
videos = filter(lambda x : x.endswith("mp4") , videos)

for each_video in videos:
    print each_video

    each_video_name , _ = each_video.split('.')
    m = video_save_path + '/' + each_video_name

    if(os.path.exists(m) == False):
        os.mkdir(m)  #新建“D:/mtcnn/Mathbook_pic/Mathbook/”文件夹
    each_video_save_full_path = os.path.join(video_save_path, each_video_name) + '/'

    each_video_full_path = video_src_path + '/' + each_video
    print each_video_full_path
    cap = cv2.VideoCapture(each_video_full_path)

    if False == cap.isOpened():
        print 'open video failed'  
    else:
        print 'open video succeeded'

    count = 0   #统计帧数
    frame_gap = 10  #间隔为10帧，每个10帧读取第10帧
    success = True
    i = 0
    #每隔10帧读取一帧
    while(success):
        success , frame = cap.read()
        i = i + 1
        if(i == frame_gap):  #每个10帧读取第10帧
            print success
            #print 'Read a new frame:' , success
            params = []
            params.append(int(cv2.IMWRITE_JPEG_QUALITY))
            params.append(95)
            cv2.imwrite(each_video_save_full_path + each_video_name + '_%d.jpg' % count , frame , params)
            count = count + 1
            i = 0

    cap.release()
print 'OK！'

注意的是，对于cv2库的VideoCapture函数，如果之前使用的是Pip 安装的opencv的python库，则没有安装FFmPeg，会导致无法正常打开视频，需要按下面步骤进行操作：

参考链接：http://blog.csdn.net/yedasha/article/details/78128345