Gray-level encoded fringe projection for profile measurements

摘要

An encoding algorithm to identify the fringe orders for Fourier transform profilometry is described. Phase unwrapping is then performed with reference to the encoding algorithm. Even though the inspected object is colorful or sensitive to the reflectance variation, unwrapping can be performed without ambiguity. The computation cost is very low, and its unwrapped errors can be confined in a local area.