Event-Driven Fringe Projection Structured Light 3-D Reconstruction Based on Time–Frequency Analysis

Event-based structured light (eSL) 3-D measurement systems overcome intrinsic limitations of frame-based structured light (fSL) 3-D measurement systems, such as sensor dynamic range, pixel bandwidth, and system optical power. However, most of the existing methods are based on laser scanning, and they are not only limited by the speed of acquisition but are also very sensitive to noise events. This article proposes an efficient event-driven fringe projection structured light (eFPSL) 3-D reconstruction system, aiming for high-precision 3-D measurements at increased acquisition speeds. Leveraging a digital light processing fringe projection system, eFPSL enhances the acquisition speed. We further develop a time–frequency analysis algorithm capable of efficiently converting event streams into 2-D fringe intensity images with high signal-to-noise ratio and excellent sinusoidality, thus mitigating noise event impacts. Moreover, a novel events-count-based shadow mask extraction (eSME) strategy is proposed to eliminate shadow noise. Experimental validations demonstrate eFPSL’s ability to produce higher precision 3-D reconstructions, reducing mean absolute error (MAE) by 64% compared to the existing eSL methods. In addition, eFPSL impressively safeguards comprehensive 3-D results while reducing system power consumption, achieving an 82% reduction in system optical power compared to traditional fSL systems. Most importantly, for high dynamic range (HDR) scenes, eFPSL achieves visual representation and measurement accuracy comparable to eight measurements of fSL systems using only a single measurement, indicating an 87.5% improvement in measurement efficiency. Hence, our experiments confirm that eFPSL’s adaptability can extend to HDR scenes involving high-speed motion.