Flexible Extrinsic Structured Light Calibration Using Circles

Abstract

We introduce a novel structured light extrinsic calibration framework that emphasizes calibration flexibility while maintaining satisfactory accuracy. The proposed method facilitates extrinsic calibration by projecting circles into non-planar and dynamically changing scenes over multiple distances without relying on the structured light’s intrinsics. Our approach relies on extracting depth information using stereo-cameras. The implementation reconstructs light-rays by detecting the center of circles and reconstructing their 3D-positions using triangulation. We evaluate our method by using synthetically rendered images under relevant lighting- and scene conditions, including detection drop-out, circle-center detection error, impact of distances and impact of different scenes. Our implementation achieves a rotational accuracy of below 1 degree and a translational accuracy of approximately 1 cm. Based on our experimental results we expect our approach to be applicable for use cases in w hich more flexible extrinsic structured light calibration techniques are required, such as automotive headlight calibration.