We previously presented a technique calibrating a multiaperture array projector (MAAP) for performing high-speed three-dimensional (3-D) surface topology measurements with aperiodic sinusoidal fringe structured illumination. Although a stereo-camera setup used to be required for triangulation, the presented MAAP calibration technique re-enables photogrammetric 3-D measurements to be made using a single CCD or CMOS camera. For such a monocular-view photogrammetric system, intrinsic camera calibration, intrinsic projector calibration, and extrinsic system calibration are vital to obtain high-measurement performance. However, there is currently no such technique that can comprehensively perform the required extrinsic system calibration when using an MAAP and a single-camera setup. A comprehensive optimization-based method is proposed and the resulting measurement performance is evaluated. With the new calibration technique, we are able to achieve a surface standard deviation of ∼50 μm.
In this contribution, we present new 3D sensor technologies based on three different methods of near-infrared projection technologies in combination with a stereo vision setup of two cameras. We explain the optical principles of an NIR GOBO projector, an array projector and a modified multi-aperture projection method and compare their performance parameters to each other. Further, we show some experimental measurement results of applications where we realized fast, accurate, and irritation-free measurements of human faces.
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