Motion-Induced Error Reduction for Motorized Digital Fringe Projection System

Abstract

In phase-shifting profilometry (PSP), errors can be introduced by any motion during the acquisition of fringe patterns, as it assumes both the object and the measurement system are stationary. To address this issue, we propose a pixel-wise motion-induced error reduction method when the measurement system is in motion due to a motorized system. Our proposed method introduces a novel motion-attentive phase-shifting algorithm and leverages the motor’s encoder and the pinhole model of the camera and projector. It enables accurate 3-D shape measurement with only three fringe patterns, leveraging the geometric constraints of the digital fringe projection system. We address the mismatch problem due to motion-induced camera pixel disparities and reduce phase shift errors. These processes are easy to implement and require low computational cost. Experimental results demonstrate that the presented method effectively reduces errors even in nonuniform 3-D motion.