Event-based Stereo Visual Odometry with Native Temporal Resolution via Continuous-time Gaussian Process Regression

TL;DR

This paper introduces a stereo visual odometry method that leverages continuous-time Gaussian process regression to directly utilize individual event measurements, preserving the native temporal resolution of event-based cameras and improving accuracy over existing methods.

Contribution

It presents a novel stereo VO pipeline that estimates trajectories directly from asynchronous event data without grouping, maintaining temporal fidelity with Gaussian process regression.

Findings

Achieves 7.9e-3 and 5.9e-3 RMS relative error on MVSEC sequences.

Outperforms existing event-based stereo VO pipelines by 2-4 times.

Maintains native temporal resolution of event data.

Abstract

Event-based cameras asynchronously capture individual visual changes in a scene. This makes them more robust than traditional frame-based cameras to highly dynamic motions and poor illumination. It also means that every measurement in a scene can occur at a unique time. Handling these different measurement times is a major challenge of using event-based cameras. It is often addressed in visual odometry (VO) pipelines by approximating temporally close measurements as occurring at one common time. This grouping simplifies the estimation problem but, absent additional sensors, sacrifices the inherent temporal resolution of event-based cameras. This paper instead presents a complete stereo VO pipeline that estimates directly with individual event-measurement times without requiring any grouping or approximation in the estimation state. It uses continuous-time trajectory estimation to maintain the temporal fidelity and asynchronous nature of event-based cameras through Gaussian process regression with a physically motivated prior. Its performance is evaluated on the MVSEC dataset, where it achieves 7.9e-3 and 5.9e-3 RMS relative error on two independent sequences, outperforming the existing publicly available event-based stereo VO pipeline by two and four times, respectively.