Recent Advances in Open Set Recognition: A Survey
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Abstract (arXiv)
In real-world recognition/classification tasks, limited by various objective factors, it is usually difficult to collect training samples to exhaust all classes when training a recognizer or classifier. A more realistic scenario is open set recognition (OSR), where incomplete knowledge of the world exists at training time, and unknown classes can be submitted to an algorithm during testing, requiring the classifiers to not only accurately classify the seen classes, but also effectively deal with the unseen ones. This paper provides a comprehensive survey of existing open set recognition techniques covering various aspects ranging from related definitions, representations of models, datasets, evaluation criteria, and algorithm comparisons. Furthermore, we briefly analyze the relationships between OSR and its related tasks including zero-shot, one-shot (few-shot) recognition/learning techniques, classification with reject option, and so forth. Additionally, we also overview the open world recognition which can be seen as a natural extension of OSR. Importantly, we highlight the limitations of existing approaches and point out some promising subsequent research directions in this field.
Key facts. Cited by 310 papers in the map (data through 14 Oct 2026). First posted on arXiv 21 Nov 2018.
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Citing papers per year: 2020: 1; 2021: 51; 2022: 59; 2023: 59; 2024: 60; 2025: 42; 2026: 38.
310 papers.
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- 2022Learning to Prompt for Open-Vocabulary Object Detection with Vision-Language Model28 Mar 2022
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- 2022Language-driven Semantic Segmentationcited by 717
- 2021Towards Out-Of-Distribution Generalization: A Surveycited by 436
- 2022ADBench: Anomaly Detection Benchmarkcited by 232
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- 2022A Model or 603 Exemplars: Towards Memory-Efficient Class-Incremental Learningcited by 154
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- 2022Plex: Towards Reliability using Pretrained Large Model Extensionscited by 102
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- 2026SPOC-Net: Single-Primitive Online Composition Network for GNSS Jamming Set Recognition28 Sep 2026
- 2026Cross-Dataset Transfer and Unknown-Class Detection in Imbalanced SAR Ship Classification15 Sep 2026
- 2026Generalized Biomedicine Discovery9 Sep 2026
- 2026CoGe-GCD: Reframing Generalized Category Discovery with Compositional Generalization9 Sep 2026
- 2026Open-Set Cattle Muzzle Identification: A Leakage-Controlled Benchmark and Evaluation Protocol22 Aug 2026
- 2026MedXplore: Towards Reliable and Unbiased Generalized Category Discovery in Medical Imaging30 Jul 2026
- 2026Rank-1 Identity Consensus Predicts Gallery Enrollment in 1:N Face Matching More Accurately than Score Thresholding14 Jul 2026
- 2026Position: Stop Reactively Patching Your Model Every Time and Start Proactive Test-Driven AI Development10 Jul 2026
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- 2026Few-Shot Open-Set Audio Classification Using Attention Information-Fused Prototypes1 Jul 2026
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