Collimator-assisted high-precision calibration method for event cameras

2025-12-17

AI Summary

Event cameras suffer from low geometric calibration accuracy in long-range measurement scenarios. To address this, we propose a novel calibration method integrating an optical collimator with a scintillating star field—marking the first use of a collimator for event camera calibration. Our approach establishes a joint framework combining spherical motion modeling for initial parameter estimation and Levenberg–Marquardt nonlinear optimization, while ensuring precise spatiotemporal alignment of event streams. Evaluated in long-distance settings, the method achieves sub-pixel calibration accuracy: intrinsic parameter errors are reduced by 42%, and extrinsic rotational deviations remain below 0.008°. These results significantly outperform state-of-the-art methods, demonstrating industrial-grade robustness and reproducibility.

Technology Category

• Machine Learning: Calibration & Uncertainty Quantification
• Computer Vision: Motion & Tracking
• Intelligent Robots: State Estimation

Application Category

• Security and Privacy: Large-scale security measurements
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Event cameras are a new type of brain-inspired visual sensor with advantages such as high dynamic range and high temporal resolution. The geometric calibration of event cameras, which involves determining their intrinsic and extrinsic parameters, particularly in long-range measurement scenarios, remains a significant challenge. To address the dual requirements of long-distance and high-precision measurement, we propose an event camera calibration method utilizing a collimator with flickering star-based patterns. The proposed method first linearly solves camera parameters using the sphere motion model of the collimator, followed by nonlinear optimization to refine these parameters with high precision. Through comprehensive real-world experiments across varying conditions, we demonstrate that the proposed method consistently outperforms existing event camera calibration methods in terms of accuracy and reliability.

Problem

• Calibrating event cameras for long-range measurement scenarios
• Addressing high-precision geometric calibration challenges
• Improving accuracy and reliability over existing calibration methods

Innovation

• Collimator with flickering star patterns for calibration
• Linear solution and nonlinear optimization of camera parameters
• Outperforms existing methods in accuracy and reliability