OpenCV 3 Computer Vision with Python Cookbook

How to do it...

You need to complete the following steps:

1. Import the necessary modules:

import cv2import numpy as np

2. Define a function which handles a video file. This function takes each frame, match the keypoints for this frame and the one 40 frames before:

def video_keypoints(matcher, cap=cv2.VideoCapture("../data/traffic.mp4"),                     detector=cv2.ORB_create(40)):    cap.set(cv2.CAP_PROP_POS_FRAMES, 0)    while True:        status_cap, frame = cap.read()        frame = cv2.resize(frame, (0, 0), fx=0.5, fy=0.5)        if not status_cap:            break        if (cap.get(cv2.CAP_PROP_POS_FRAMES) - 1) % 40 == 0:            key_frame = np.copy(frame)            key_points_1, descriptors_1 = detector.detectAndCompute(frame, None)        else:            key_points_2, descriptors_2 = detector.detectAndCompute(frame, None)