LECalib: Line-Based Event Camera Calibration

TL;DR

LECalib introduces a fast, line-based calibration method for event cameras that detects lines directly from event streams, avoiding manual pattern placement and enabling accurate calibration in dynamic scenarios.

Contribution

The paper proposes a novel line-based calibration framework that directly detects lines from event streams and uses an event-line model for initial estimation, improving speed and applicability.

Findings

Effective in both simulation and real-world tests

Applicable to monocular and stereo event cameras

Achieves high calibration accuracy

Abstract

Camera calibration is an essential prerequisite for event-based vision applications. Current event camera calibration methods typically involve using flashing patterns, reconstructing intensity images, and utilizing the features extracted from events. Existing methods are generally time-consuming and require manually placed calibration objects, which cannot meet the needs of rapidly changing scenarios. In this paper, we propose a line-based event camera calibration framework exploiting the geometric lines of commonly-encountered objects in man-made environments, e.g., doors, windows, boxes, etc. Different from previous methods, our method detects lines directly from event streams and leverages an event-line calibration model to generate the initial guess of camera parameters, which is suitable for both planar and non-planar lines. Then, a non-linear optimization is adopted to refine camera parameters. Both simulation and real-world experiments have demonstrated the feasibility and accuracy of our method, with validation performed on monocular and stereo event cameras. The source code is released at https://github.com/Zibin6/line_based_event_camera_calib.