  Head and human detection have been rapidly improved with the development of
deep convolutional neural networks. However, these two tasks are often studied
separately without considering their inherent correlation, leading to that 1)
head detection is often trapped in more false positives, and 2) the performance
of human detector frequently drops dramatically in crowd scenes. To handle
these two issues, we present a novel joint head and human detection network,
namely JointDet, which effectively detects head and human body simultaneously.
Moreover, we design a head-body relationship discriminating module to perform
relational learning between heads and human bodies, and leverage this learned
relationship to regain the suppressed human detections and reduce head false
positives. To verify the effectiveness of the proposed method, we annotate head
bounding boxes of the CityPersons and Caltech-USA datasets, and conduct
extensive experiments on the CrowdHuman, CityPersons and Caltech-USA datasets.
As a consequence, the proposed JointDet detector achieves state-of-the-art
performance on these three benchmarks. To facilitate further studies on the
head and human detection problem, all new annotations, source codes and trained
models will be public.
