ArUco: Camera position detection using square markers | Hugonweb Annotated Link Bibliography

https://www.uco.es/investiga/grupos/ava/portfolio/aruco/

ArUco is a library using OpenCV (see at the OpenCV website here) that allows one to detect QRCode-like markers and estimate their or the camera's location in space.

A related project, UcoSLAM, does simultaneous location and mapping.