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. Capture frames from the camera, detect a chessboard pattern on each frame, and accumulate the frames and corners until we have a big enough number of samples:

cap = cv2.VideoCapture(0)pattern_size = (10, 7)samples = []while True:    ret, frame = cap.read()    if not ret:        break        res, corners = cv2.findChessboardCorners(frame, pattern_size)        img_show = np.copy(frame)    cv2.drawChessboardCorners(img_show, pattern_size, corners, res)    cv2.putText(img_show, 'Samples captured: %d' % len(samples), (0,     40),                 cv2.FONT_HERSHEY_SIMPLEX, 1.0, (0, 255, 0), 2)    cv2.imshow('chessboard', img_show)        wait_time = 0 if res else 30 k = cv2.waitKey(wait_time) ...