3D Scene Capture by Multi-Wavelength Pattern Projection at Divergent Illumination of A Sinusoidal Phase Grating

The paper focuses on the performance of a phase-shifting profilometric system with a sinusoidal phase grating as a projection element under simultaneous multi-wavelength projection of four phase-shifted patterns at divergent illumination and simultaneous multi-camera registration. The quality of the projected fringes is evaluated by calculation of the Fresnel diffraction integral for a spherical wave illumination at paraxial approximation as well as by measurement of the contrast and the spectral content of the fringes as a function of the distance from the grating. The good quality of fringes is proved by simulation of the four-wavelength profilometric measurement. An accurate restoration of a 3D test object (dome) from experimental data is presented.