Monitoring large volumes of interest by using voxel visibility

Classical visual hull implementations are fonded on the hypothesis that the object is entirely visible by all the cameras. This limits the size of the volume to monitor. By adding visibility to the classical occupancy description, we limit the impact of each camera to the sub-volume of interest viewed by it. Different parts of the volume of interest are reconstructed by different sub-groups of cameras. Within a distributed reconstruction system, the volume of interest is no more constrained by camera placement but by the cost of the equipment and the latency of the system. We demonstrate the usage of visibility with a real time system using pinhole cameras and with sequences acquired on board of a moving train with fish eye lenses.