Novel quasi absolute phase unwrapping algorithm for 3D optical measurement

Obtaining fringe order map accurately and quickly can achieve high-precision optical three-dimensional (3D) measurement. To retrieve the absolute phase map, this letter presents a novel quasi absolute phase unwrapping method based on N+1 step line-coded phase-shifting profilometry (LPSP). Fringe order can be determined easily from wrapped phase and the single-pixel binarized (SPB) line pattern, the error occurring at the previous points will not be propagated along the phase unwrapping path, which can effectively avoid error accumulation.