Abstract
In fringe projection profilometry, using multi-frequency fringe patterns allows us to determine fringe orders automatically, thus unwrapping the measured phase maps. Simultaneously, doing this provides a possibility of correcting the effects of the projector nonlinearity directly from the captured fringe patterns. This projector nonlinearity decreases the measurement accuracies by inducing errors appearing as ripple-like artifacts on the phase maps and, further, on the reconstructed 3D shape surfaces. Theoretical analysis shows that these artifacts, depending on the number of phase shifts, have multiplied frequencies higher than the fringe frequencies, and their amplitudes are dependent on the extent of the projector nonlinearity. These facts imply that, we estimate the amplitude of the artifacts from two phase maps of the fringe patterns having different frequencies, by exploiting the statistics of the differences of their phase errors. By subtracting out the artifacts from the phase maps, the effects of the projector nonlinearity on the measurement results can be suppressed significantly. Experiment results demonstrate that this proposed method offers some advantages over others, such as working without a photometric calibration, being applicable when the projector nonlinearity varies with time, and being efficient in computation.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call