Abstract

Structured light illumination, scanning along both horizontal and vertical directions, achieves more robust accuracy. By introducing the constraint of epipolar geometry, we previously proposed real-time 3D reconstruction using lookup tables; however, we only knew these offline derived tables were the combinations of the elements in calibration matrices of a camera and a projector, and suffered from long-time computation. In this Letter, by parameterizing the line perspectively mapping a 3D world coordinate into the camera and projector spaces, we propose to extend the epipolar analysis by defining phase and optical poles. Thus, we can geometrically address these parameters via analytic closed-form equations, with which we can (1) directly derive lookup tables in real time from the calibration matrices and (2) optimally reduce the number of tables from 11 to 5 to save much more memory space while further accelerating the processing rate. Experiments show that with the same level of accuracy, we significantly reduce the time to compute the lookup tables from more than 20 min to 20 ms, and increase the speed of computing point clouds from approximately 320 to 492 fps.

© 2020 Optical Society of America

Extending epipolar geometry for real-time structured light illumination II: lossless accuracy

Kai Liu, Xuening Ran, Jun Gong, Jianwen Song, Daniel L. Lau, Ce Zhu, and Bin Xu
Opt. Lett. 46(4) 837-840 (2021)

Reconstructing 3D point clouds in real time with look-up tables for structured light scanning along both horizontal and vertical directions

Kai Liu, Jianwen Song, Daniel L. Lau, Xiujuan Zheng, Ce Zhu, and Xiaomei Yang
Opt. Lett. 44(24) 6029-6032 (2019)

Correcting projector lens distortion in real time with a scale-offset model for structured light illumination

Geyou Zhang, Bin Xu, Daniel L. Lau, Ce Zhu, and Kai Liu
Opt. Express 30(14) 24507-24522 (2022)

Divide and conquer: high-accuracy and real-time 3D reconstruction of static objects using multiple-phase-shifted structured light illumination

Kai Liu, Wenqi Hua, Jinghe Wei, Jianwen Song, Daniel L. Lau, Ce Zhu, and Bin Xu
Opt. Express 28(5) 6995-7007 (2020)

Real-time three-dimensional shape measurement of moving objects without edge errors by time-synchronized structured illumination

Daniel L. Lau, Kai Liu, and Laurence G. Hassebrook
Opt. Lett. 35(14) 2487-2489 (2010)