The Early Bird Identifies the Worm: You Can't Beat a Head Start in Long-Term Body Re-ID (ECHO-BID)
This work addresses long-term person re-identification for surveillance and security applications, but it is incremental as it builds on existing backbone architectures and transfer learning protocols.
The paper tackled the problem of person identification in unconstrained environments with challenges like clothing changes and occlusions by introducing ECHO-BID, a model based on object-pretrained EVA-02 Large backbones, which achieved state-of-the-art results on long-term re-id, substantially outperforming other methods in occluded scenarios.
Person identification in unconstrained viewing environments presents significant challenges due to variations in distance, viewpoint, imaging conditions, and clothing. We introduce $\textbf{E}$va $\textbf{C}$lothes-Change from $\textbf{H}$idden $\textbf{O}$bjects - $\textbf{B}$ody $\textbf{ID}$entification (ECHO-BID), a class of long-term re-id models built on object-pretrained EVA-02 Large backbones. We compare ECHO-BID to 9 other models that vary systematically in backbone architecture, model size, scale of object classification pretraining, and transfer learning protocol. Models were evaluated on benchmark datasets across constrained, unconstrained, and occluded settings. ECHO-BID, with transfer learning on the most challenging clothes-change data, achieved state-of-the-art results on long-term re-id -- substantially outperforming other methods. ECHO-BID also surpassed other methods by a wide margin in occluded viewing scenarios. A combination of increased model size and Masked Image Modeling during pretraining underlie ECHO-BID's strong performance on long-term re-id. Notably, a smaller, but more challenging transfer learning dataset, generalized better across datasets than a larger, less challenging one. However, the larger dataset with an additional fine-tuning step proved best on the most difficult data. Selecting the correct pretrained backbone architecture and transfer learning protocols can drive substantial gains in long-term re-id performance.