Fringe demodulation using the two-dimensional phase differencing operator

The Letter proposes a method for phase estimation from a fringe pattern. The proposed method relies on a parametric approach where the phase is locally approximated as a two-dimensional (2D) polynomial, with the ensuing polynomial coefficients as the respective parameters. These coefficients are then estimated using the phase differencing operator. Because of the 2D formulation, the proposed method simultaneously analyzes signal samples along the horizontal and vertical dimensions, which enables robust estimation in the presence of noise. In addition, the method directly provides the desired phase without the requirement of complex unwrapping algorithms. Simulation and experimental results are presented to validate the method's potential.