🤖 AI Summary
Existing HOI detection methods are limited to pairwise relationship modeling, failing to capture collective interactions involving multiple humans and objects co-occurring in realistic scenes. To address this, we propose the first group-centric HOI detection framework, which dynamically clusters HOI instances via a learnable spatial proximity grouping mechanism. We further design a local context-enhanced Transformer decoder that explicitly models soft HOI correspondences in self-attention, while jointly encoding bounding box geometry and semantic features to strengthen higher-order interaction representation. Our approach achieves state-of-the-art performance on HICO-DET and V-COCO, and significantly outperforms prior methods on the more challenging non-linguistic interaction detection task—demonstrating superior generalization to complex, multi-agent interactive scenarios.
📝 Abstract
Human-Object Interaction Detection (HOI-DET) aims to localize human-object pairs and identify their interactive relationships. To aggregate contextual cues, existing methods typically propagate information across all detected entities via self-attention mechanisms, or establish message passing between humans and objects with bipartite graphs. However, they primarily focus on pairwise relationships, overlooking that interactions in real-world scenarios often emerge from collective behaviors (multiple humans and objects engaging in joint activities). In light of this, we revisit relation modeling from a group view and propose GroupHOI, a framework that propagates contextual information in terms of geometric proximity and semantic similarity. To exploit the geometric proximity, humans and objects are grouped into distinct clusters using a learnable proximity estimator based on spatial features derived from bounding boxes. In each group, a soft correspondence is computed via self-attention to aggregate and dispatch contextual cues. To incorporate the semantic similarity, we enhance the vanilla transformer-based interaction decoder with local contextual cues from HO-pair features. Extensive experiments on HICO-DET and V-COCO benchmarks demonstrate the superiority of GroupHOI over the state-of-the-art methods. It also exhibits leading performance on the more challenging Nonverbal Interaction Detection (NVI-DET) task, which involves varied forms of higher-order interactions within groups.