I. Introduction
Egocentric vision can offer sufficient information about how people perceive the world and interact with the environment from a human-centric perspective, furnishing diverse opportunities for the analysis of human behavior and cognition [1], [2]. In general, an egocentric vision system can be composed of either head-mounted or chest-mounted cameras, capturing the visual data in a free-living environment with increased mobility and flexibility. Recent progress in egocentric vision has been widely penetrated in daily life assistive healthcare, including human behavior analysis [2], human-machine interaction [3], and social interaction characterization and assistance [4].