A Free Lunch for Unsupervised Domain Adaptive Object Detection without Source Data

Authors

  • Xianfeng Li South China University of Technology
  • Weijie Chen Zhejiang University Hikvision Research Institute
  • Di Xie Hikvision Research Institute
  • Shicai Yang Hikvision Research Institute
  • Peng Yuan Hikvision Research Institute
  • Shiliang Pu Hikvision Research Institute
  • Yueting Zhuang Zhejiang University

Keywords:

Transfer/Adaptation/Multi-task/Meta/Automated Learning

Abstract

Unsupervised domain adaptation (UDA) assumes that source and target domain data are freely available and usually trained together to reduce the domain gap. However, considering the data privacy and the inefficiency of data transmission, it is impractical in real scenarios. Hence, it draws our eyes to optimize the network in the target domain without accessing labeled source data. To explore this direction in object detection, for the first time, we propose a source data-free domain adaptive object detection (SFOD) framework via modeling it into a problem of learning with noisy labels. Generally, a straightforward method is to leverage the pre-trained network from the source domain to generate the pseudo labels for target domain optimization. However, it is difficult to evaluate the quality of pseudo labels since no labels are available in target domain. In this paper, self-entropy descent (SED) is a metric proposed to search an appropriate confidence threshold for reliable pseudo label generation without using any handcrafted labels. Nonetheless, completely clean labels are still unattainable. After a thorough experimental analysis, false negatives are found to dominate in the generated noisy labels. Undoubtedly, false negatives mining is helpful for performance improvement, and we ease it to false negatives simulation through data augmentation like Mosaic. Extensive experiments conducted in four representative adaptation tasks have demonstrated that the proposed framework can easily achieve state-of-the-art performance. From another view, it also reminds the UDA community that the labeled source data are not fully exploited in the existing methods.

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Published

2021-05-18

How to Cite

Li, X., Chen, W., Xie, D., Yang, S., Yuan, P., Pu, S., & Zhuang, Y. (2021). A Free Lunch for Unsupervised Domain Adaptive Object Detection without Source Data. Proceedings of the AAAI Conference on Artificial Intelligence, 35(10), 8474-8481. Retrieved from https://ojs.aaai.org/index.php/AAAI/article/view/17029

Issue

Section

AAAI Technical Track on Machine Learning III