Robust video person re-identification via hierarchical cross-attention mechanisms
摘要
Video person re-identification (ReID) aims to retrieve video sequences of the same individual across non-overlapping camera views. Despite rich temporal cues, cross-camera trajectories often suffer from temporal misalignment and inconsistent action phases due to varying viewpoints and motion states. We propose a robust two-stage video retrieval system tailored for compute-budget-constrained surveillance deployments. The first stage employs a self-attention-based Transformer to learn global video representations and generate a high-recall Top-K candidate set. The second stage introduces a Hierarchical Cross-Attention Reordering (HCAR) module to capture fine-grained spatial correspondences and perform content-based keyframe matching, mitigating occlusion and temporal misalignment. Experiments on MARS, iLIDS-VID, and PRID2011, together with controlled analyses on MARS, show that the proposed sparse refinement improves retrieval performance over the same baseline retriever while avoiding dense full-gallery re-ranking. The source code is publicly available at: https://github.com/Lwj-68668/HCAR-ReID. https://doi.org/10.6084/m9.figshare.31410519.