Consistent GT-Proposal Assignment for Challenging Pedestrian Detection

Accurate pedestrian classification and localization has garnered significant attention due to their extensive applications in various multimedia applications such as security monitoring, autonomous driving, and more. We have observed that the commonly employed Intersection over Union (IoU) metric in many pedestrian detectors is susceptible to an inconsistent GT-Proposal assignment issue. This issue arises when spatially adjacent proposals, which have highly similar features, are assigned to distinct ground-truth boxes, leading to confusion during the training process and an increased number of false positives during inference. To address this challenge, our work presents a novel algorithm named
D
irectional
A
ssignment
S
trategy (
DAS
). Firstly, in conjunction with depth distribution, our approach transforms the assignment metric from a two-dimensional (2D) view into a three-dimensional (3D) space, enabling the optimization of the regression head under the constraint of depth direction. Secondly, in contrast to the conventional IoU-based
one-to-one
assignment of one proposal to one ground-truth box, our method aims to establish a more reasoned matching between sets of proposals and ground-truth boxes. By doing so, the detector is less reliant on the setting of a specific threshold. Leveraging this strategy as a plug-in module within state-of-the-art pedestrian detectors, we demonstrate a notable improvement in performance.