Tutorials

Checker board

https://docs.opencv.org/4.x/d6/d55/tutorial_table_of_content_calib3d.html https://docs.opencv.org/4.x/d9/db7/tutorial_py_table_of_contents_calib3d.html

Aruco

https://docs.opencv.org/4.x/d2/d64/tutorial_table_of_content_objdetect.html

Sample code

CPP

https://github.com/opencv/opencv/tree/4.x/samples/cpp/tutorial_code/objectDetection

Python

https://github.com/opencv/opencv_contrib/tree/4.x/modules/aruco