Discovering the Structure of a Planar Mirror System from Multiple Observations of a Single Point
We investigate the problem of identifying the position of a viewer inside a room of planar mirrors with unknown geometry in conjunction with the room’s shape parameters. We consider the observations to consist of angularly resolved depth measurements of a single scene point that is being observed via many multi-bounce interactions with the specular room geometry. Applications of this problem statement include areas such as calibration, acoustic echo cancelation and time-of-flight imaging. We theoretically analyze the problem and derive sufficient conditions for a combination of convex room geometry, observer, and scene point to be reconstructable. The resulting constructive algorithm is exponential in nature and, therefore, not directly applicable to practical scenarios. To counter the situation, we propose theoretically devised geo- metric constraints that enable an efficient pruning of the solution space and develop a heuristic randomized search algorithm that uses these constraints to obtain an effective solution. We demon- strate the effectiveness of our algorithm on extensive simulations as well as in a challenging real-world calibration scenario.
AddressDr. Ivo Ihrke
INRIA Bordeaux Sud-Ouest
200 avenue de la vieille tour
If arriving by train, take tram line "C" towards "Les Aubiers" up to the stop "Quinconces", then switch to line "B" towards "Pessac". Exit at "Arts et Metiers". Then cross the bridge and turn left towards the INRIA building.