# Person Re-identification in Aerial Imagery

## TL;DR

This paper introduces a new large-scale dataset for person re-identification in aerial imagery captured by UAVs and proposes a novel feature representation method that improves re-identification performance in this challenging setting.

## Contribution

The paper presents the PRAI-1581 dataset for aerial person ReID and a subspace pooling method for discriminative feature learning, advancing research in UAV-based surveillance.

## Key findings

- ReID in aerial imagery is highly challenging.
- Proposed method outperforms existing approaches.
- Dataset facilitates future UAV surveillance research.

## Abstract

Nowadays, with the rapid development of consumer Unmanned Aerial Vehicles (UAVs), visual surveillance by utilizing the UAV platform has been very attractive. Most of the research works for UAV captured visual data are mainly focused on the tasks of object detection and tracking. However, limited attention has been paid to the task of person Re-identification (ReID) which has been widely studied in ordinary surveillance cameras with fixed emplacements. In this paper, to facilitate the research of person ReID in aerial imagery, we collect a large scale airborne person ReID dataset named as Person ReID for Aerial Imagery (PRAI-1581), which consists of 39,461 images of 1581 person identities. The images of the dataset are shot by two DJI consumer UAVs flying at an altitude ranging from 20 to 60 meters above the ground, which covers most of the real UAV surveillance scenarios. In addition, we propose to utilize subspace pooling of convolution feature maps to represent the input person images. Our method can learn a discriminative and compact feature representation for ReID in aerial imagery and can be trained in an end-to-end fashion efficiently. We conduct extensive experiments on the proposed dataset and the experimental results demonstrate that re-identify persons in aerial imagery is a challenging problem, where our method performs favorably against state of the arts. Our dataset can be accessed via \url{https://github.com/stormyoung/PRAI-1581}.