Structured Light with Redundancy Codes

TL;DR

This paper introduces a redundancy coding technique for structured light systems to enhance robustness against ambient light, interference, and global illumination, improving 3D reconstruction accuracy in challenging environments.

Contribution

The paper presents a novel redundancy coding approach for structured light that enables error correction, detection, and interference filtering, with practical hardware prototypes and real-world evaluations.

Findings

Significant performance improvements in structured light accuracy.

Effective error correction under strong ambient light.

Robust interference filtering in complex scenes.

Abstract

Structured light (SL) systems acquire high-fidelity 3D geometry with active illumination projection. Conventional systems exhibit challenges when working in environments with strong ambient illumination, global illumination and cross-device interference. This paper proposes a general-purposed technique to improve the robustness of SL by projecting redundant optical signals in addition to the native SL patterns. In this way, projected signals become more distinguishable from errors. Thus the geometry information can be more easily recovered using simple signal processing and the ``coding gain" in performance is obtained. We propose three applications using our redundancy codes: (1) Self error-correction for SL imaging under strong ambient light, (2) Error detection for adaptive reconstruction under global illumination, and (3) Interference filtering with device-specific projection sequence encoding, especially for event camera-based SL and light curtain devices. We systematically analyze the design rules and signal processing algorithms in these applications. Corresponding hardware prototypes are built for evaluations on real-world complex scenes. Experimental results on the synthetic and real data demonstrate the significant performance improvements in SL systems with our redundancy codes.