  Identifying different objects (man and cup) is an important problem on its
own, but identifying the relationship between them (holding) is critical for
many real world use cases. This paper describes an approach to reduce a visual
relationship detection problem to object detection problems. The method was
applied to Google AI Open Images V4 Visual Relationship Track Challenge, which
was held in conjunction with 2018 European Conference on Computer Vision (ECCV
2018) and it finished as a prize winner. The challenge was to build an
algorithm that detects pairs of objects in particular relations: things like
"woman playing guitar," "beer on table," or "dog inside car.".
