Abstract
Source-free domain adaptive person re-identification (ReID) aims to address the cross-domain person ReID task with a well-trained source model, which solves the limitations of data privacy and transmission costs in real-world scenarios. Existing methods mainly generate pseudo labels for target data, which are unreliable because of distribution shifts. First, the ubiquitous difficult samples may lead to the ambiguity of the model prediction. Second, the source model may have a bias towards certain classes. To alleviate these two problems, we propose a source-free domain adaptive person ReID method via the uncertain label refinery (RULER). RULER consists of uncertainty-aware pseudo-labeling refinery (UPLR) and frequency-weighted contrastive learning (FCL). To reduce the ambiguity of predictions caused by sample label uncertainty, UPLR generates pseudo labels by clustering samples after multiple random dropouts and then integrates the results to obtain high-confidence pseudo labels. Moreover, FCL defines the frequency of each class as the sample weight and introduces a frequency-weighted contrastive loss to alleviate the class biases of the model. RULER improves the quality of pseudo labels and mitigates the source model′s bias towards certain classes. We achieve competitive results compared to state-of-the-art methods on both real-to-real and synthetic-to-real source-free domain adaptation scenarios, validating the effectiveness of RULER.
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This work was supported in part by the National Natural Science Foundation of China (Nos. 62372003 and 62376004), the Natural Science Foundation of Anhui Province, China (Nos. 2308085Y40 and 2208085J18), and the University Synergy Innovation Program of Anhui Province, China (No. GXXT-2022-036).
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Aihua Zheng received the B. Eng. degree and finished Master-Doctor Combined Program in computer science and technology from Anhui University, China in 2006 and 2008, respectively, and the Ph. D. degree in computer science from University of Greenwich, UK in 2012. She visited University of Stirling, UK during June to September in 2013 and Texas State University, USA during September 2019 to August 2020, respectively. She is currently a professor and the Ph. D. supervisor at the School of Artificial Intelligence, Anhui University, China.
Her research interests include person/vehicle re-identification, audio-visual computing, and multi-modal intelligence.
Zhihao Fei received the B. Eng. degree in computer science and technology from West Anhui University, China in 2022, and is currently a master student in the School of Artificial Intelligence, Anhui University, China.
His research interests include computer vision, domain adaptation and person reidentification.
Yuhe Ding received the B. Eng. degree in computer science from Anhui University, China in 2019. She is currently a Ph. D. degree candidate in the School of Computer Science and Technology, Anhui University, China. From 2020 to 2022, she was a visiting student at Institute of Automation, Chinese Academy of Sciences, China.
Her research interests include transfer learning, pattern recognition, and computer vision.
Chenglong Li received the M. Sc. and Ph. D. degrees in computer application technology from the School of Computer Science and Technology, Anhui University, China in 2013 and 2016, respectively. From 2014 to 2015, he worked as a visiting student with the School of Data and Computer Science, Sun Yat-sen University, China. He was a postdoctoral research fellow at the Center for Research on Intelligent Perception and Computing (CRIPAC), National Laboratory of Pattern Recognition (NLPR), Institute of Automation, Chinese Academy of Sciences (CASIA), China. He is currently a professor and Ph. D. supervisor at the School of Artificial Intelligence, Anhui University, China. He was a recipient of the ACM Hefei Doctoral Dissertation Award in 2016.
His research interests include computer vision and deep learning.
Bin Luo received the B. Eng. degree in electronics and the M. Eng. degree in computer science from the Anhui University, China in 1984 and 1991, respectively, and the Ph. D. degree in computer science from the University of York, UK in 2002. He has authored or coauthored more than 200 papers in journals and refereed conferences. He is currently a professor with the Anhui University, China. He is currently the Chair of the IEEE Hefei Subsection. He was a peer reviewer of international academic journals, such as IEEE Transactions on Pattern Analysis and Machine Intelligence, Pattern Recognition, and Pattern Recognition Letters.
His research interests include random graph-based pattern recognition, image and graph matching, and spectral analysis.
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Zheng, A., Fei, Z., Ding, Y. et al. RULER: Source-free Domain Adaptive Person Re-identification via Uncertain Label Refinery. Mach. Intell. Res. 22, 900–916 (2025). https://doi.org/10.1007/s11633-025-1543-7
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DOI: https://doi.org/10.1007/s11633-025-1543-7