ProgressFace: Scale-Aware Progressive Learning for Face Detection

Jiashu Zhu, Dong Li, Tiantian Han, Lu Tian, Yi Shan ;

Scale variation stands out as one of key challenges in face detection. Recent attempts have been made to cope with this issue by incorporating image / feature pyramids or adjusting anchor sampling / matching strategies. In this work, we propose a novel scale-aware progressive training mechanism to address large scale variations across faces. Inspired by curriculum learning, our method gradually learns large-to-small face instances. The preceding models learned with easier samples (i.e., large faces) can provide good initialization for succeeding learning with harder samples (i.e., small faces), ultimately deriving a better optimum of face detectors. Moreover, we propose an auxiliary anchor-free enhancement module to facilitate the learning of small faces by supplying positive anchors that may be not covered according to the criterion of IoU overlap. Such anchor-free module will be removed during inference and hence no extra computation cost is introduced. Extensive experimental results demonstrate the superiority of our method compared to the state-of-the-arts on the standard FDDB and WIDER FACE benchmarks. Especially, our ProgressFace-Light with MobileNet-0.25 backbone achieves 87.9% AP on the hard set of WIDER FACE, surpassing largely RetinaFace with the same backbone by 9.7%. Code and our trained face detection models are available at https://github.com/jiashu-zhu/ProgressFace."