Pseudo-label based unsupervised fine-tuning of a monocular 3D pose estimation model for sports motions
Tomohiro Suzuki, Ryota Tanaka, Kazuya Takeda, Keisuke Fujii
Abstract
Accurate motion capture is useful for sports motion analysis, but requires higher acquisition costs. Monocular or few camera multi-view pose estimation provides an accessible but less accurate alternative, especially for sports motion, due to training on datasets of daily activities. In addition, multi-view estimation is still costly due to camera calibration. Therefore, it is desirable to develop an accurate and cost-effective motion capture system for the daily training in sports. In this paper, we propose an accurate and convenient sports motion capture system based on unsupervised fine-tuning. The proposed system estimates 3D joint positions by multi-view estimation based on automatic calibration with the human body. These results are used as pseudo-labels for fine-tuning of the recent higher performance monocular 3D pose estimation model. Since the fine-tuning improves the model accuracy for sports motion, we can choose multi-view or monocular estimation depending on the situation. We evaluated the system using a running motion dataset and ASPset-510, and showed that fine-tuning improved the performance of monocular estimation to the same level as that of multi-view estimation for running motion. Our proposed system can be useful for the daily motion analysis in sports.