Multiprojector Multicamera Structured Light Surface Scanner

Structured light surface scanners are usually limited to a single projector and cannot provide a full surface profile in a single scan. Multiple projectors must be employed to extend the imaging area over the whole surface of the imaged object. Using multiple projectors is a challenging problem due to inter-projector interference which makes pattern decoding hard. We describe a practical approach to multi-projector structured light surface scanning based on sinusoidal fringe patterns and temporal phase shifting which allows simultaneous projector employment. In our approach a different set of temporal phase shifts is assigned to each projector to enable an efficient and robust separation of observed combined patterns into the contributions of each projector. The proposed approach does not place any restrictions on projector placement nor on the upper limit of the number of projectors used. We demonstrate the applicability of the proposed approach on a structured light surface scanner comprised of three projectors and six cameras.