6dof EMob: Occlusion-Free 3D Position and Orientation Measurement Under Clothing - 25.33
Title:
6dof EMob: Occlusion-Free 3D Position and Orientation Measurement Under Clothing
Authors:
Yixian CHENG 1, Hannah GULKA 1, Luis BOLANOS 1, Pearson WYDER-HODGE 1, Ye FAN 1,2, Dinesh K. PAI 1,2
1 University of British Columbia, Canada;
2 Vital Mechanics Research Inc., Canada
Keywords:
Measurement under clothing, SE(3), electromagnetic tracking, spatially varying corrections, neural networks, calibration framework
Abstract:
Measuring 3D human bodies under clothing remains a challenging problem due to occlusion. Yet, this
is an ultimate goal of many human body measurement systems. In a recent breakthrough, we introduced a novel system called EMob for measuring under clothing using electromagnetic (EM) tracking. EMob utilizes remarkably small (as small as 1.8mm diameter) electromagnetic sensors that can be attached to the skin or hidden layers of clothing. A sensor (EMu, ElectroMagnetic unit) can be tracked at high rates (up to 960 fps, though we use 240 fps in our experiments) using a Polhemus electromagnetic tracking system.
However, the previous work only utilized the positions of these sensors. The electromagnetic sensors are capable of measuring orientations as well, enabling full 6 degree-of-freedom (6dof) tracking. In this work, we extend the EMob system to leverage both position and orientation data. This 6dof tracking significantly complicates the calibration process, as the electromagnetic sensors are subject to spatially varying distortions caused by environmental factors, which can lead to inaccuracies in both position and orientation measurements. We address this challenge by implementing a neural network that learns spatially varying corrections on SE(3), the group of rigid body transformations, to improve the accuracy of the EM tracking system. With our novel data-driven calibration, the EMob system can be effectively used in challenging environments, such as inside a 3D body scanner.
The 6dof EMob system offers numerous practical applications. Anthropometric landmarks can be accurately located under clothing during 3D body scanning and consistently tracked across different body poses. We have also successfully demonstrated the system's effectiveness in a real-world application, measuring and quantifying the relative motion between skin and clothing during dynamic activities.
Abstract:
Presentation:
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How to Cite (MLA):
Cheng, Yixian, et al., "6dof EMob: Occlusion-Free 3D Position and Orientation Measurement Under Clothing", Proceedings of 3DBODY.TECH 2025 - 16th International Conference and Expo on 3D/4D Body Scanning, Data and Processing Technologies, Lugano, Switzerland, 21-22 Oct. 2025, #33
Details:
Proceedings: 3DBODY.TECH 2025, 21-22 Oct. 2025, Lugano, Switzerland
Paper/Presentation: #33
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