HORP: Human-Object Relation Priors Guided HOI Detection

Human-Object Interaction (HOI) detection aims to predict the $<$Human, Interaction, Object$>$ triplets, where the core challenge lies in recognizing the interaction of each human-object pair. Despite recent progress thanks to more advanced model architectures, HOI performance remains unsatisfactory. In this work, we first perform some failure analysis and find that the accuracy for the no-interaction category is extremely low, largely hindering the improvement of overall performance. We further look into the error types and find the mis-classification between no-interaction and with-interaction ones can be handled by human-object relation priors. Specifically, to better distinguish no-interaction from direct interactions, we propose 3D location prior, which indicates the distance between human and object; as of no-interaction vs. indirect interactions, we propose gaze area prior, which denotes whether human can see the object or not. The above two types of human-object relation priors are represented by text and are combined with the original visual features, generating multi-modal cues for interaction recognition.Experimental results on the HICO-DET and V-COCO datasets demonstrate that our proposed human-object relation priors are effective and our method HORP surpasses previous methods under various settings and scenarios. In particular, the usage of our priors significantly enhances the model's recognition ability for the no-interaction category, by a large margin of 10.9 pp.