Ego4o: Egocentric Human Motion Capture and Understanding from Multi-Modal Input
This work addresses motion capture challenges for applications in VR/AR and wearable technology, representing an incremental advancement by integrating existing methods like VQ-VAE and LLMs for multi-modal inputs.
The paper tackles the problem of tracking and understanding human motion from diverse, multi-modal consumer wearable devices, achieving accurate motion prediction and high-quality motion descriptions through a framework that maintains performance with partial inputs and improves with combined modalities.
This work focuses on tracking and understanding human motion using consumer wearable devices, such as VR/AR headsets, smart glasses, cellphones, and smartwatches. These devices provide diverse, multi-modal sensor inputs, including egocentric images, and 1-3 sparse IMU sensors in varied combinations. Motion descriptions can also accompany these signals. The diverse input modalities and their intermittent availability pose challenges for consistent motion capture and understanding. In this work, we present Ego4o (o for omni), a new framework for simultaneous human motion capture and understanding from multi-modal egocentric inputs. This method maintains performance with partial inputs while achieving better results when multiple modalities are combined. First, the IMU sensor inputs, the optional egocentric image, and text description of human motion are encoded into the latent space of a motion VQ-VAE. Next, the latent vectors are sent to the VQ-VAE decoder and optimized to track human motion. When motion descriptions are unavailable, the latent vectors can be input into a multi-modal LLM to generate human motion descriptions, which can further enhance motion capture accuracy. Quantitative and qualitative evaluations demonstrate the effectiveness of our method in predicting accurate human motion and high-quality motion descriptions.