Structured light is a non-contact three-dimensional shape measurement method. The structured light system based on diffractive optical elements (DOEs) is widely used due to its low cost and compact structure.… Click to show full abstract
Structured light is a non-contact three-dimensional shape measurement method. The structured light system based on diffractive optical elements (DOEs) is widely used due to its low cost and compact structure. However, compared with a time sequence coded structured light system based on a digital projector, its projector cannot change the content, so it cannot be calibrated with a phase-shift-based method. This paper proposes a calibration method based on the pseudo-camera method and digital image correlation (DIC). It is suitable not only for the calibration of systems based on time series coding but also for the calibration of a speckle structured light system based on DOEs. Validation experiments were conducted in which our method achieved a reprojection error of 0.68 pixels in calibration and a radius error of less than 1% in a measurement of a cylinder in a 20cm×10cm field. Compared with existing calibration methods, this method does not need to set a datum plane, takes fewer photos, operates simply, and has higher calibration efficiency.
               
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