Multi-Person Hierarchical 3D Pose Estimation in Natural Videos

Despite the increasing need of analyzing human poses on the street and in the wild, multi-person 3D pose estimation using monocular static or moving camera in real-world scenarios remains a challenge, either requiring large-scale training data or high computation complexity due to the high degrees of freedom in 3D human poses. We propose a novel scheme to effectively track and hierarchically estimate 3D human poses in natural videos in an efficient fashion. Without the need of using labelled 3D training data, we formulate torso estimation as a Perspective-N-Point (PNP) problem, and limb pose estimation as an optimization problem, and hierarchically structure the high dimensional poses to efficiently address the challenge. Experiments show good performance and high efficiency of multi-person 3D pose estimation on real-world videos, including street scenarios and various human daily activities from fixed and moving cameras, resulting in great new opportunities to understand and predict human behaviors.