I. Introduction
Person re-identification [1]–[4] has received considerable academic attention, owing to its tremendous potential in security applications such as people tracking [5] and behavior analysis [6]. The essential objective of person Re-ID is to identify target persons from a large number of person images. These images are taken under various viewpoints, different illuminations, and human poses, which leads to a large intra-personal variation severely hindering the identification. The recent success of person Re-ID models stems from the deep convolutional neural networks [7]–[9]. Due to its convincing discriminative ability, the deep leaning methods provide a powerful person image representation that can partly alleviate these issues and hence show the superiority.