BFBox: Searching Face-Appropriate Backbone and Feature Pyramid Network for Face Detector

Popular backbones designed on image classification have demonstrated their considerable compatibility on the task of general object detection. However, the same phenomenon does not appear on the face detection. This is largely due to the average scale of ground-truth in the WiderFace dataset is far smaller than that of generic objects in theCOCO one. To resolve this, the success of Neural Archi-tecture Search (NAS) inspires us to search face-appropriate backbone and featrue pyramid network (FPN) architecture.Firstly, we design the search space for backbone and FPN by comparing performance of feature maps with different backbones and excellent FPN architectures on the face detection. Second, we propose a FPN-attention module to joint search the architecture of backbone and FPN. Finally,we conduct comprehensive experiments on popular bench-marks, including Wider Face, FDDB, AFW and PASCALFace, display the superiority of our proposed method.