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| import cv2, numpy as np, os | |
| board_w, board_h = 6, 9 | |
| board_size = (board_w, board_h) | |
| img_w, img_h = 720, 1280 | |
| img_size = (img_w, img_h) | |
| square_mm = 21 | |
| def get_obect_img_pts(board_img, debug=False): | |
| board_img_grey = cv2.cvtColor(board_img, cv2.COLOR_BGR2GRAY) | |
| # Find chessboard corners | |
| found, corners = cv2.findChessboardCorners( | |
| image=board_img_grey, | |
| patternSize=board_size, | |
| flags=cv2.CALIB_CB_ADAPTIVE_THRESH | cv2.CALIB_CB_FILTER_QUADS | cv2.CALIB_CB_FAST_CHECK) | |
| # Refine corner locations | |
| cv2.cornerSubPix( | |
| image=board_img_grey, | |
| corners=corners, | |
| winSize=(11, 11), | |
| zeroZone=(-1, -1), | |
| criteria=(cv2.TERM_CRITERIA_EPS | cv2.TERM_CRITERIA_COUNT, 30, 0.1)) | |
| if debug: | |
| chessboard_debug_img = np.copy(board_img) | |
| chessboard_debug_img = cv2.cvtColor(chessboard_debug_img,cv2.COLOR_BGR2GRAY) | |
| chessboard_debug_img = cv2.cvtColor(chessboard_debug_img,cv2.COLOR_GRAY2BGR) | |
| cv2.drawChessboardCorners(chessboard_debug_img, board_size, corners, found) | |
| cv2.imshow("board", chessboard_debug_img) | |
| cv2.waitKey() | |
| # Correctly arrange arrays of corresponding points | |
| object_pts = np.zeros((np.prod(board_size), 3), np.float32) | |
| object_pts[:, :2] = np.indices(board_size).T.reshape(-1, 2) * square_mm | |
| image_pts = corners.reshape(-1, 2) | |
| return object_pts, image_pts | |
| def get_intrinsic_camera_params(object_pts, image_pts, debug=False): | |
| _, cam_mat, dist_coefs, _, _ = cv2.calibrateCamera( | |
| objectPoints=object_pts, | |
| imagePoints=image_pts, | |
| imageSize=img_size) | |
| if debug: | |
| print dist_coefs | |
| print cam_mat | |
| print 'fx = {}, fy = {}'.format(cam_mat[0][0], cam_mat[1][1]) | |
| print 'cx = {}, cy = {}'.format(cam_mat[0][2], cam_mat[1][2]) | |
| return cam_mat, dist_coefs | |
| #---------------------------------------- | |
| # FIND INTRINSIC CAMERA PARAMETERS | |
| #---------------------------------------- | |
| if __name__ == '__main__': | |
| calibration_imgs_path = 'camera_calibration' | |
| calibration_imgs = map(lambda x: cv2.imread(os.path.join(calibration_imgs_path, x)), | |
| os.listdir(calibration_imgs_path)) | |
| all_object_pts, all_img_pts = [], [] | |
| for img in calibration_imgs: | |
| object_pts, image_pts = get_obect_img_pts(img, debug=True) | |
| all_object_pts.append(object_pts) | |
| all_img_pts.append(image_pts) | |
| cam_mat, dist_coefs = get_intrinsic_camera_params(all_object_pts, all_img_pts, True) | |
| params_file = open('camera_matrix_N7.txt', 'w') | |
| params_file.write('fx = {}\nfy = {}\ncx = {}\ncy = {}'.format(cam_mat[0][0], cam_mat[1][1], cam_mat[0][2], cam_mat[1][2])) | |
| params_file.close() |