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Learn from the Learnt: Source-Free Active Domain Adaptation via Contrastive Sampling and Visual Persistence

26 Jul 2024arXiv:2407.18899archive 2025-07-28

Mengyao Lyu, Tianxiang Hao, Xinhao Xu, Hui Chen, Zijia Lin, Jungong Han, Guiguang Ding

Domain Adaptation (DA) facilitates knowledge transfer from a source domain to a related target domain. This paper investigates a practical DA paradigm, namely Source data-Free Active Domain Adaptation (SFADA), where source data becomes inaccessible during adaptation, and a minimum amount of annotation budget is available in the target domain. Without referencing the source data, new challenges emerge in identifying the most informative target samples for labeling, establishing cross-domain alignment during adaptation, and ensuring continuous performance improvements through the iterative query-and-adaptation process. In response, we present learn from the learnt (LFTL), a novel paradigm for SFADA to leverage the learnt knowledge from the source pretrained model and actively iterated models without extra overhead. We propose Contrastive Active Sampling to learn from the hypotheses of the preceding model, thereby querying target samples that are both informative to the current model and persistently challenging throughout active learning. During adaptation, we learn from features of actively selected anchors obtained from previous intermediate models, so that the Visual Persistence-guided Adaptation can facilitate feature distribution alignment and active sample exploitation. Extensive experiments on three widely-used benchmarks show that our LFTL achieves state-of-the-art performance, superior computational efficiency and continuous improvements as the annotation budget increases. Our code is available at https://github.com/lyumengyao/lftl.

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MixedDataset lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran · metamorphic tier: deterministic fingerprinted no licence file found · pointer only · b79fcefc19df1ff4 · report
Strategy lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran no licence file found · pointer only · 5237eafffa541c27 · report
cal_acc lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran · our draft was wrong fingerprinted no licence file found · pointer only · e5b1dfbb42d000c2 · report
cosine_metric lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran · our draft was wrong fingerprinted no licence file found · pointer only · c5bba296dc9e0db3 · report
cross_entropy_loss lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran · our draft was wrong no licence file found · pointer only · a84c8b8443596255 · report
info_maximize_loss lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology ran · our draft was wrong fingerprinted no licence file found · pointer only · bec6249a0ed0c414 · report
CASampling lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology unverified no licence file found · pointer only · b7d77cf003e36c17 · report
print_log lyumengyao/lftl/mining/contrastive_sampling.py found in paper text by Syntology unverified no licence file found · pointer only · 2448f73c9a9561b9 · report

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Active LearningComputational EfficiencyDomain AdaptationTransfer Learning

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