Sign Recognition

The task of automatically detecting, reading, and interpreting signs in an environment — for accessibility purposes, typically indoor directional signs (arrows pointing to corridors or facilities) and textual signs (room numbers, department names, wayfinding labels). Sign recognition combines object detection (to locate arrows or text regions), optical character recognition (to read the text), and a grouping step that associates each arrow with the text it belongs to, so that instructions such as 'Corridor 4200, to the right' can be delivered as audio to a blind traveller. Sign recognition is a key component of map-less indoor navigation systems because the signs themselves already encode the route information that a prebuilt map would otherwise have to store.