Abstract:
A 3D shape measurement method combining sinusoidal pulse width modulation fringe with phase coding fringe was proposed. Two kinds of coding fringes were projected onto the object with defocus. Using a phase-shift algorithm, the wrapped phase was obtained by the sinusoidal pulse width modulation fringe, the fringe order was got by the phase coding fringe. Then, the three-dimensional shape of the measurement object can be restored. The experimental results demonstrate that the proposed method has two merits:(1) It can decrease the measurement error because of filtering the harmonics with slight defocus;(2) It can measure the different contrast object because it is based on phase code.