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#!/usr/bin/env python
import argparse
import os
import time
from argaze.ArUcoMarkers import ArUcoMarkersDictionary, ArUcoBoard, ArUcoDetector, ArUcoCamera
import cv2
def main():
"""
Captures board pictures and finally outputs camera calibration data into a calibration.json file.
- Export and print a calibration board using aruco_calibration_board_export.py script.
- Place the calibration board face to the camera.
- Move the calibration board in a manner to view it entirely on screen in various configurations (orientation and distance):
The script will automatically take pictures. Do this step with a good lighting and a clear background.
- Once enough pictures have been captured (~20), press Esc key then, wait for the camera calibration processing.
- Finally, check rms parameter: it should be between 0. and 1. if the calibration succeeded (lower is better).
### Reference:
- [Camera calibration using ArUco marker tutorial](https://automaticaddison.com/how-to-perform-camera-calibration-using-opencv/)
"""
# Manage arguments
parser = argparse.ArgumentParser(description=main.__doc__.split('-')[0])
parser.add_argument('columns', metavar='COLS_NUMBER', type=int, default=7, help='expected board columns number')
parser.add_argument('rows', metavar='ROWS_NUMBER', type=int, default=5, help='expected board rows number')
parser.add_argument('square_size', metavar='SQUARE_SIZE', type=float, default=5, help='expected square size in cm')
parser.add_argument('marker_size', metavar='MARKER_SIZE', type=float, default=3, help='expected marker size in cm')
parser.add_argument('dictionary', metavar='DICTIONARY', type=ArUcoMarkersDictionary.ArUcoMarkersDictionary, default='DICT_ARUCO_ORIGINAL', help='expected dictionary name: DICT_4X4_50, DICT_4X4_100, DICT_4X4_250, DICT_4X4_1000, DICT_5X5_50, DICT_5X5_100, DICT_5X5_250, DICT_5X5_1000, DICT_6X6_50, DICT_6X6_100, DICT_6X6_250, DICT_6X6_1000, DICT_7X7_50, DICT_7X7_100, DICT_7X7_250, DICT_7X7_1000, DICT_ARUCO_ORIGINAL, DICT_APRILTAG_16h5, DICT_APRILTAG_25h9, DICT_APRILTAG_36h10, DICT_APRILTAG_36h11')
parser.add_argument('-d', '--device', metavar='DEVICE', type=int, default=0, help='video capture device id')
parser.add_argument('-o', '--output', metavar='OUT', type=str, default='.', help='destination folder filepath')
args = parser.parse_args()
# Enable camera video capture
video_capture = cv2.VideoCapture(args.device)
frame_width = int(video_capture.get(cv2.CAP_PROP_FRAME_WIDTH))
frame_height = int(video_capture.get(cv2.CAP_PROP_FRAME_HEIGHT))
# Create aruco camera
aruco_camera = ArUcoCamera.ArUcoCamera(dimensions=(frame_width, frame_height))
# Create aruco board
aruco_board = ArUcoBoard.ArUcoBoard(args.columns, args.rows, args.square_size, args.marker_size, args.dictionary)
# Create aruco detector
aruco_detector = ArUcoDetector.ArUcoDetector(dictionary=args.dictionary, marker_size=args.marker_size)
print(f'{aruco_camera.dimensions[0]}x{aruco_camera.dimensions[1]} pixels camera calibration starts')
print("Waiting for calibration board...")
expected_markers_number = aruco_board.markers_number
expected_corners_number = aruco_board.corners_number
# Capture loop
try:
# Capture frames with a full displayed board inside
while video_capture.isOpened():
success, video_frame = video_capture.read()
if success:
# Detect calibration board
aruco_detector.detect_board(video_frame, aruco_board, expected_markers_number)
# Draw detected markers
aruco_detector.draw_detected_markers(video_frame)
# Draw current calibration data count
cv2.putText(video_frame, f'Capture: {aruco_camera.calibration_data_count}', (50, 50), cv2.FONT_HERSHEY_SIMPLEX, 1, (255, 255, 255), 2, cv2.LINE_AA)
cv2.imshow('Camera Calibration', video_frame)
# If all board corners are detected
if aruco_detector.board_corners_number == expected_corners_number:
# Draw board corners to notify a capture is done
aruco_detector.draw_board(video_frame)
# Append calibration data
aruco_camera.store_calibration_data(aruco_detector.board_corners, aruco_detector.board_corners_identifier)
cv2.imshow('Camera Calibration', video_frame)
# Stop calibration by pressing 'Esc' key
if cv2.waitKey(1) == 27:
break
# Stop calibration on 'ctrl+C' interruption
except KeyboardInterrupt:
pass
# Stop frame display
cv2.destroyAllWindows()
print('\nCalibrating camera...')
aruco_camera.calibrate(aruco_board)
print('\nCalibration succeeded!')
print(f'\nRMS:\n{aruco_camera.rms}')
print(f'\nDimensions:\n{frame_width}x{frame_height}')
print(f'\nCamera matrix:\n{aruco_camera.K}')
print(f'\nDistortion coefficients:\n{aruco_camera.D}')
aruco_camera.to_json(f'{args.output}/calibration.json')
print(f'\ncalibration.json file exported into {args.output} folder')
if __name__ == '__main__':
main()
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