Groupwise Query Specialization and Quality-Aware Multi-Assignment for Transformer-based Visual Relationship Detection

Visual Relationship Detection (VRD) has seen significant advancements with Transformer-based architectures recently. However we identify two key limitations in a conventional label assignment for training Transformer-based VRD models which is a process of mapping a ground-truth (GT) to a prediction. Under the conventional assignment an 'unspecialized' query is trained since a query is expected to detect every relation which makes it difficult for a query to specialize in specific relations. Furthermore a query is also insufficiently trained since a GT is assigned only to a single prediction therefore near-correct or even correct predictions are suppressed by being assigned 'no relation' as a GT. To address these issues we propose Groupwise Query Specialization and Quality-Aware Multi-Assignment (SpeaQ). Groupwise Query Specialization trains a 'specialized' query by dividing queries and relations into disjoint groups and directing a query in a specific query group solely toward relations in the corresponding relation group. Quality-Aware Multi-Assignment further facilitates the training by assigning a GT to multiple predictions that are significantly close to a GT in terms of a subject an object and the relation in between. Experimental results and analyses show that SpeaQ effectively trains 'specialized' queries which better utilize the capacity of a model resulting in consistent performance gains with 'zero' additional inference cost across multiple VRD models and benchmarks. Code is available at https://github.com/mlvlab/SpeaQ.