HOPNet: Learning Hand-Object-Person Interaction Network for Hand Contact State Detection

The detection of hand contact states, which involves identifying interactions between hands and objects or other entities, is essential for the development of human-computer interaction systems and the comprehension of social dynamics. Previous approaches have made progress in modeling hand-object interactions. Nonetheless, they neglect critical cues between their hands and bodies, as well as those of others, thus constraining their ability to accurately detect interpersonal contact. The task remains challenging due to frequent occlusions, especially in crowded multi-person scenarios with complex contexts. In this paper, a novel hand-object-person interaction network, called HOPNet, is proposed to model contextual information between hands and objects, as well as between hands and bodies. Specifically, HOPNet consists of two components: (i) the Hand-Object Relation (HOR) module analyzes interaction patterns between hands and objects, capturing spatial and semantic relationships; (ii) the Contrastive Spatial Refinement (CSR) module learns hand-body interactions through contrastive geometric embedding and relative spatial enhancement, improving interpersonal contact recognition in crowded scenarios. Experiments on ContactHands and 100DOH datasets demonstrate that HOPNet outperforms state-of-the-art methods.