Camera Calibration using a Collimator System

TL;DR

This paper presents a novel camera calibration method using a collimator system that simplifies the calibration process by reducing the motion model, and demonstrates superior performance over existing methods in both synthetic and real-world tests.

Contribution

The paper introduces a collimator-based calibration approach that simplifies motion modeling and provides closed-form solutions, improving calibration accuracy and flexibility.

Findings

Method outperforms state-of-the-art calibration techniques.

Collimator system effectively simplifies the calibration process.

Validated with both synthetic and real-world experiments.

Abstract

Camera calibration is a crucial step in photogrammetry and 3D vision applications. In practical scenarios with a long working distance to cover a wide area, target-based calibration methods become complicated and inflexible due to site limitations. This paper introduces a novel camera calibration method using a collimator system, which can provide a reliable and controllable calibration environment for cameras with varying working distances. Based on the optical geometry of the collimator system, we prove that the relative motion between the target and camera conforms to the spherical motion model, reducing the original 6DOF relative motion to 3DOF pure rotation motion. Furthermore, a closed-form solver for multiple views and a minimal solver for two views are proposed for camera calibration. The performance of our method is evaluated in both synthetic and real-world experiments, which verify the feasibility of calibration using the collimator system and demonstrate that our method is superior to the state-of-the-art methods. Demo code is available at https://github.com/LiangSK98/CollimatorCalibration.