Discussion on accurate phase–height mapping in fringe projection profilometry

Establishing a highly accurate phase-to-height mapping relationship is very important in fringe projection profilometry, which guarantees the accuracy of final three-dimensional reconstruction. The influence coming from lens distortion, random noises, and the nontelecentric projecting and imaging of the measurement system is analyzed in detail, followed by the exhaustive discussion of a more accurate phase-to-height mapping method. The mapping tabulation between absolute phase and height information is set up by the piecewise linear fitting method within the whole measurement range for per-pixel. Our method is compared with the previously used methods, such as linear fitting (LF), quadratic fitting (QF), and cubic fitting (CF) methods. Computer simulations and experiments verify that the reconstructed height distribution employing our method is more accurate than either LF or QF methods when the random noise is obvious. In addition, if the random noise can be controlled to low level and the lens distortion is considered, the reconstruction accuracy of our method is better than that of the CF method.