AR Marker

A printed visual pattern (often a square with a distinctive black-and-white code) placed in the environment that a smartphone or AR headset camera can recognise to determine its own position and orientation with high precision. In blind-navigation research, AR markers are placed on walls or floors and scanned by the user's phone to provide an initial localisation fix, after which visual inertial odometry tracks the user's movement. This 'marker + VIO' pattern is simpler and often more accurate for indoor assistance than Wi-Fi RSS or BLE-beacon localisation, but it requires one-time environmental preparation and maintenance of the markers.