Object-Based Camera Pose Estimation from a Single Object Detection and Gravity Vector

1 - Department of Automation, Technical University of Cluj-Napoca
Strada Memorandumului 28, 400114, Romania
{Szilard.Molnar,Levente.Tamas}@aut.utcluj.ro
2 - Institute of Informatics, University of Szeged
P.O. Box 652, H-6701 Szeged, Hungary,
{amstadt,kato}@inf.u-szeged.hu

Abstract

Recent results on pose estimation from ellipsoid-ellipse correspondences, which can be readily obtained from an object detector, allow a direct computation of the camera pose from object-level correspondences. Unfortunately, standard bounding boxes (either horizontal or minimal enclosing boxes) are symmetric, which introduces an inherent ambiguity in the correspondence, yielding multiple or even infinite solutions. Furthermore, the current state of the art requires minimum two such correspondences to provide sufficient constraints for camera rotation. Our contributions make object-based pose estimation efficient in practice: First, a novel object detection method is proposed, called Directional Object Bounding Box (DOBB), which is capable of detecting the object’s own direction together with its minimal enclosing box (OBB), yet independently from it, which not only breaks the symmetry of OBBs, but also provides the necessary additional geometric information for our pose estimation method. Second, a novel object-based robust camera pose estimation pipeline is proposed where a minimal solution can be obtained from a single object for outlier filtering when vertical direction and the object orientation w.r.t. that axis are known; followed by a closed-form least squares solution for multiple inlier objects to compute the camera pose. Comparative tests confirm the state-of-the-art performance of the proposed DOBB-based pose estimation method on the standard KITTI360 and 7-Scenes datasets.

Alternative Text

Acknowledgments

This work was supported by Romanian National Authority for Scientific Research, project nr. PN-IV-P7-7.1-PTE-2024-0105; by the ATLAS project funded by the EU CHIST-ERA programme (CHIST-ERA-23-MultiGIS-02) and the Hungarian National Research, Development and Innovation Fund under grants 2024-1.2.2-ERA-NET-2025-00020, TKP2021-NVA-09, and K135728 and HAS Domus.

BibTeX

@InProceedings{molnar2025isvc_dobb_objectbasedcamerapose,
      author    = {Molnar, Szilard and Amstadt, Zita and Tamas, Levente and Kato, Zoltan},
      booktitle = {{ISVC 2025 20th International Symposium on Visual Computing}},
      title     = {{Object-Based Camera Pose Estimation from a Single Object Detection and Gravity Vector}},
      year      = {2025},
      note      = {Presented at the conference, waiting for the proceeding publication},
    }