Multi-demodulation phase-shifting and intensity pattern projection profilometry

Phase-shifting is a powerful phase demodulation method for three-dimensional imaging by fringe projection. However, numerous fringe patterns, which encode a single-phase function, are required. In this paper, the use of intensity patterns, which encode multiple phase functions, is proposed. A multi-demodulation phase-shifting algorithm and the intensity pattern projection profilometry approach are developed. A computer simulation and an experimental three-dimensional object measurement are performed to validate the proposal and demonstrate its effectiveness. The results exhibit that a similar accuracy than conventional fringe projection is achieved while using a reduced number of patterns. The proposed approach is a feasible alternative to increase the efficiency of three-dimensional imaging systems based on phase-shifting.