Fringe projection 3D imaging optimized for accuracy and efficiency

In three-dimensional (3D) imaging based on fringe projection profilometry (FPP), <i>N</i>-step phase-shifting algorithm (PSA) and three-frequency temporal phase unwrapping (TPU) are widely used for the high-precision and robust 3D shape restoration. However, the large number of fringes led to a decrease in measurement efficiency. The accuracy and efficiency in FPP are often contradictory. To reduce the number of fringes while achieving high-precision absolute phase extraction, this paper proposes a three-frequency TPU based on the 1H + 2M + 3L algorithm. The proposed method not only rivals the absolute phase recovery accuracy and phase unwrapping reliability of the commonly used 3H + 3M + 3L algorithm, but also improves 3D measurement efficiency. The experimental results have demonstrated the effectiveness of the proposed method. The proposed algorithm provides a reference for the balance accuracy and efficiency of FPP in actual 3D measurement.