Phase shifts extraction based on time-domain orthogonal character of phase-shifting interferograms

Based on the time-domain orthogonal character of different pixel intensity variation of phase-shifting interferograms, a novel non-iterative algorithm is proposed to achieve the phase shifts in random phase-shifting interferometry. Due to there is no requirement for the fringe number of phase-shifting interferograms, the proposed algorithm can work well even in the case that the fringe number of interferogram is less than one, which is a difficult problem in interferometry. Moreover, only two one-dimensional vectors, achieved from the average intensity of several pixels of interferogram, are enough to perform the phase shifts extraction, the proposed algorithm reveals rapid processing speed. Specially, compared with the conventional phase shifts extraction algorithms, the proposed algorithm does not need to perform the pixel-pixel calculation or the iterative calculation, so its processing speed is greatly improved. Both the simulation and the experiment demonstrate the outstanding performance of the proposed algorithm.