A Two-step Method for Extrinsic Calibration between a Sparse 3D LiDAR and a Thermal Camera

Abstract

To obtain the 6 DOF extrinsic parameters (rotation and translation matrix) between a 3D ranging sensor and a thermal camera, previous methods require a high-resolution 3D ranging sensor to reliably detect features. Although sparse 3D LiDARs are widely used on autonomous robots, to the best of our knowledge, the extrinsic calibration between a sparse 3D LiDAR (particularly Velodyne VLP-16) and a thermal camera has not been considered in the literature. In this paper, we present a two-step method to address the problem, where a monocular visual camera is used to assist the process. The proposed method decomposes the problem into two steps: extrinsic calibration between a sparse 3D LiDAR and a visual camera; extrinsic calibration between a visual camera and a thermal camera. Experiments are conducted to demonstrate the effectiveness of the proposed two-step method.