VFNet
VarifocalNet
**VarifocalNet** is a method aimed at accurately ranking a huge number of candidate detections in object detection. It consists of a new loss function, named [Varifocal Loss](https://paperswithcode.com/method/varifocal-loss), for training a dense object detector to predict the IACS, and a new efficient star-shaped bounding box feature representation for estimating the IACS and refining coarse bounding boxes. Combining these two new components and a bounding box refinement branch, results in a dense object detector on the [FCOS](https://paperswithcode.com/method/fcos) architecture, what the authors call VarifocalNet or VFNet for short.
VarifocalNet: An IoU-aware Dense Object Detector
https://paperswithcode.com/paper/varifocalnet-an-iou-aware-dense-object
VarifocalNet: An IoU-aware Dense Object Detector