REVIEW 2 major objections 5 minor 111 references
Outlier Synthesis via Hamiltonian Monte Carlo for Out-of-Distribution Detection
T0 review · 2 major / 5 minor · reviewed 2026-08-10 · deepseek-v4-flash
Pith's one-line read HamOS generates diverse virtual outliers from in-distribution data alone by running Hamiltonian Monte Carlo chains in the hyperspherical feature space, and reports state-of-the-art OOD detection on CIFAR-10, CIFAR-100, and ImageNet-1K.
desk verdict HamOS genuinely does something new — Hamiltonian Monte Carlo for virtual outlier synthesis — and the standard-benchmark gains hold up, but its own hard-OOD table shows the 'diverse and representative' claim is only true between clusters. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The load-bearing object is the OOD-ness potential energy $U^{OOD}(z; Z_u, Z_v) = -\log P^{OOD}(z; Z_u, Z_v)$, where $P^{OOD}$ is the averaged Euclidean distance from $z$ to the $k$-th nearest neighbor in each of two ID class clusters; this function is used as the potential in spherical Hamiltonian Monte Carlo on the unit sphere. The machinery also includes the class-pair midpoints used as chain initializations, a hard margin derived from von Mises-Fisher kernel density estimation that rejects proposals landing near ID clusters, and the training objective $L_{HamOS} = L_{CE} + L_{ID-con} + \lambda_d L_{OOD-disc}$ that pushes synthesized outliers away from ID prototypes.
What would settle it
Take a fixed pretrained encoder and compare HamOS against a variant that synthesizes outliers on the sphere's periphery far from all clusters, evaluating both on a near-OOD test set built by corrupting in-distribution images; if the peripheral variant wins on near-OOD data, the between-cluster prior is not capturing the OOD geometries that matter.
Extended reading notes
Core claim
The central claim is that the missing ingredient for strong OOD detection is not real outlier data but a sampling scheme that explores the feature space with sufficient diversity; the paper argues that Markov-chain traversal guided by the averaged k-th nearest-neighbor distance to a pair of ID clusters produces exactly such outliers. Starting from cluster midpoints and moving along HMC trajectories from low to high OOD-ness regions, the chains collect points that occupy a continuum of OOD scores without entering the ID clusters, which the authors identify as the reason HamOS outperforms Gaussian-sampling baselines like VOS and NPOS. The authors further claim that this synthesis is cheap enough for large-scale use and that the framework is a general shell, working with several HMC variants, scoring functions, and ID contrastive losses.
Load-bearing premise
The whole method rests on the premise that the most effective OOD supervision signals live in the region between and around the in-distribution class clusters in the hyperspherical embedding, and that the averaged k-th nearest-neighbor distance to two clusters is a faithful measure of how out-of-distribution a point is.
Editorial extensions
If this is right
- OOD-aware training no longer depends on collecting natural outlier pools, which matters for domains where high-quality OOD data are scarce or expensive.
- The reported gains on fine-tuned pretrained models suggest that any deployed classifier can be made more reliable in 20 epochs using only its own training data.
- Because HamOS is compatible with multiple HMC variants, post-hoc scoring functions, and ID contrastive losses, improvements in any of those components can be absorbed directly.
- The same synthesis scheme could regularize other representation-learning tasks that need explicit negative supervision beyond class boundaries.
Reading between the lines
- The between-cluster prior is a substantive modeling choice: if deployment OOD data concentrates along other regions of the sphere (e.g., far from all clusters), the synthesized outliers may miss the critical boundary, and a hybrid that also samples peripheral regions could be needed.
- The Markov-chain view suggests a direct bridge to score-based generative models: replacing the k-NN energy with a learned score function could adapt synthesis to the data manifold, at the cost of extra parameters.
- The method's dependence on fine-grained cluster structure may make it sensitive to the number of classes and cluster separability, so a test on datasets with many overlapping classes (e.g., fine-grained recognition) would clarify how general the gain is.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes HamOS, a method for out-of-distribution (OOD) detection that synthesizes virtual outliers in the hyperspherical feature space of a pretrained classifier using only in-distribution data. OOD-ness of a candidate point is defined (Eqs. 1–2) as the average Euclidean distance to the k-th nearest neighbor in each of two ID classes; spherical Hamiltonian Monte Carlo chains are initialized at the midpoints of nearby class prototypes and evolved by Leapfrog updates driven by the gradient of the potential (Eq. 4), with a hard margin (Eq. 5) that rejects proposals whose estimated von Mises-Fisher KDE ID probability is too high. The collected trajectory points serve as virtual outliers in an OOD-discernment loss (Eq. 7), jointly optimized with the CE loss and a CIDER-style ID contrastive loss (Eq. 8); inference uses the KNN distance to the ID embedding set (Section 3.4). The main experiments (Tables 1–2) report averaged FPR95 of 10.48% on CIFAR-10 and 46.68% on CIFAR-100 over five OOD test sets, and 44.59% on ImageNet-1K, surpassing the compared baselines on the standard benchmarks; the appendix contains ablations over sampling algorithms, scoring functions, contrastive losses, feature dimensions, and all hyperparameters, plus results on hard OOD benchmarks and from-scratch training.
Significance. The paper's strengths are empirical and reproducible: public code, multi-run means with standard deviations throughout, precise algorithm specifications (Algorithms 1–2), and unusually complete ablations covering sampling algorithms, scoring functions, contrastive losses, feature dimensions, and every free hyperparameter (Tables 9–24). If correct, the central result is genuinely useful: feature-space outlier synthesis is not restricted to Gaussian perturbations around boundary anchors, and gradient-guided exploration of the hypersphere provides cheap, effective OOD supervision without any natural outlier data. Table 9 offers a clean decomposition showing that the gain over random-walk exploration (CIFAR-100 FPR95 50.05 vs 46.68) is attributable to the gradient guidance rather than to the Markov-chain machinery itself.
major comments (2)
- [Section 3.2 (Eqs. 1–2, Eq. 5); Appendix F.1 (Tables 6–7)] The construction confines the support of the synthesized outliers to the regions between pairs of ID clusters: chains are initialized at cluster midpoints, the potential in Eq. (2) averages the distances to two clusters, and the gradient in Eq. (4) pushes points away from both clusters simultaneously, while the hard margin in Eq. (5) only blocks points that enter the bulk of the ID distribution. OOD inputs that resemble a single ID class (the hard/near-OOD regime) can therefore have low OOD-ness under Eq. (1) and are underrepresented in the synthesized distribution. This mechanism is consistent with the paper's own Table 7: with CIFAR-100 as ID, HamOS obtains averaged FPR95 of 62.32, behind SSD+ (58.80) and CIDER (60.62), although it is best on the standard five-dataset benchmark (Table 1) and does win Table 6 with CIFAR-10 as ID. The abstract and Section 3.1 claims that the framework generates 'diverse and representative outliers' exposing the model to 'miscellaneous potential OOD scenarios' should be qualified to the between-cluster regime, and the unconditional SOTA phrasing in Section 4.2 should carry the Table 7 caveat; the hedged wording in Appendix F.1 is welcome but the main text and abstract overstate the generality.
- [Section 3.2 (Eqs. 2–5); Algorithm 1 (lines 17–19)] The text states that 'the virtual outliers collected along the Markov chains obey the marginal distribution ∝ P_OOD', but this does not hold for the implemented procedure. First, the same paragraph explicitly disclaims convergence and the method runs only R=5 rounds from cluster midpoints, collecting trajectory samples rather than stationary samples from the target. Second, the hard-margin filter in Eq. (5) and Algorithm 1 line 19 is applied on top of the Metropolis acceptance probability, which breaks detailed balance; the accepted samples are not drawn from exp(−U_OOD). Third, the gradient in Eq. (4) treats the k-th nearest neighbors as constants although they depend on the current position z, and the potential in Eq. (1) is non-smooth where the k-th neighbor index changes, so the Leapfrog updates do not integrate the exact Hamiltonian defined by Eq. (2). None of this invalidates the empirical gains, which the ablation against Random Walk in Table 9 shows come from gradient-guided exploration, but the theoretical framing should be corrected: the paper should describe the chain outputs as guided exploration trajectories and drop or qualify the target-distribution claim.
minor comments (5)
- [Throughout] Typos: 'establishs' (contribution list), 'demonstates' (Section 1), 'Temporature' (Appendix E.1), 'desnity' (Appendix G), 'verying' (text near Table 19); the manuscript would benefit from a proofread.
- [Section 3.2 (Eqs. 1–2)] Terminology: Eq. (1) defines P_OOD as a Euclidean distance, not a probability; the text variously calls it 'OOD-ness density', 'OOD-ness probability level', and 'likelihood' (Sections 2.2 and 3.2). Consistent terminology such as 'OOD-ness score' would avoid the implication that the quantity is normalized.
- [Abstract; Sections 2.2 and 3.2; Table 9] The abstract and Sections 2.2 and 3.2 claim an acceptance rate 'almost close to 1', but no empirical acceptance rate is reported anywhere, and the hard-margin filter necessarily rejects some proposals; Table 9 reports only synthesis time. Reporting the measured acceptance rate per configuration would substantiate the claim.
- [Section 3.4; Appendix E.1; Table 4] The inference-time KNN scorer uses k=50 (Appendix E.1) whereas the synthesis potential uses k=200 (Table 4); a sentence on the choice and sensitivity of the inference-time k would improve reproducibility.
- [Section 3.4; Tables 10–11] The synthesis potential (Eqs. 1–2) and the inference score (Section 3.4) both use KNN distance, which is a mild self-reference; the consistent gains under Mahalanobis distance (Table 10) and under the MSP/EBO/ASH/Scale/Relation scorers (Table 11) largely mitigate the concern, and this mitigation should be stated explicitly in the main text.
Circularity Check
No significant circularity: HamOS synthesizes outliers solely from ID embeddings and its headline FPR95/AUROC numbers are measured on held-out natural OOD sets; the only self-citation is a non-load-bearing related-work mention, and the KNN-based training/inference alignment does not force the external-benchmark results.
full rationale
HamOS's derivation chain is self-contained against external benchmarks. The virtual outliers are synthesized purely from ID feature embeddings: the OOD-ness potential is defined in Eqs. (1)-(2) as the averaged k-th nearest-neighbor distance to pairs of ID class clusters, HMC samples from the density proportional to that potential (Section 3.2, Eq. (3)), and the model is fine-tuned with CE, ID-contrastive, and OOD-discernment losses (Eq. (8)). All reported FPR95/AUROC/AUPR values are computed on held-out natural OOD test sets (MNIST, SVHN, Textures, Places365, LSUN for CIFAR IDs; iNaturalist, Textures, SUN, Places for ImageNet-1K) that are never used to synthesize outliers or to select hyperparameters, so the central claim does not reduce to fitting the benchmark. The single self-citation (Zhu et al., 2023a, 'Unleashing mask', which shares co-author Hengzhuang Li with the present paper) appears only as a one-line related-work remark in Appendix B.1 ('UM (Zhu et al., 2023a) inspects the middle training stage for better detection ability') and supports no load-bearing premise of HamOS, so it is not circular. The design choice of using KNN distance both for the synthesis potential (Eq. (2)) and for the inference-time score (Section 3.4) aligns the training objective with the evaluation metric, a mild self-reference shared with prior work (KNN, KNN+, NPOS); because the final evaluation uses real OOD data not seen during training, the SOTA result does not collapse into this self-reference. The paper's own hard-benchmark results (Table 7: HamOS averaged FPR95 of 62.32 with CIFAR-100 as ID, worse than SSD+ at 58.80 and CIDER at 60.62) are honestly reported and reveal a coverage limitation of the between-cluster synthesis region for near-distribution OOD; this is a robustness concern about the 'representative outliers' claim, explicitly acknowledged in Appendix F.1 ('none of the methods achieve absolute superiority with CIFAR-100 as the ID dataset, indicating the difficulty of this benchmark'), not an internal circularity. Overall the derivation is independent and externally falsifiable.
Assumptions & free parameters
free parameters (8)
- k (kNN neighbors for OOD-ness) =
200 for CIFAR, 100 for ImageNet
- epsilon (HMC step size) =
0.1
- L (Leapfrog steps) =
3
- delta (hard margin) =
0.1
- Nadj (nearest ID clusters) =
4
- R (synthesis rounds) =
5
- lambda_d (OOD-discernment loss weight) =
0.1
- kappa (vMF KDE bandwidth) =
2.0
assumptions (4)
- domain assumption OOD-ness can be estimated by the average k-th nearest neighbor distance to a pair of ID clusters in the hyperspherical embedding.
- domain assumption The most informative virtual outliers lie between or around ID class clusters, so midpoints of cluster pairs are good initialization points.
- domain assumption The von Mises-Fisher kernel density estimate with fixed bandwidth kappa accurately models ID density for the hard margin rejection.
- domain assumption Pretrained model features provide a suitable space for synthesis, and no natural OOD data is needed for training.
Cite this review
Pith. "Pith review of Outlier Synthesis via Hamiltonian Monte Carlo for Out-of-Distribution Detection." pith.science (2026). https://pith.science/paper/JIUHOO2U
@misc{pith2026250116718,
author = {Pith},
title = {Pith review of: Outlier Synthesis via Hamiltonian Monte Carlo for Out-of-Distribution Detection},
year = {2026},
howpublished = {\url{https://pith.science/paper/JIUHOO2U}},
note = {Machine review of arXiv:2501.16718}
}
read the original abstract
Out-of-distribution (OOD) detection is crucial for developing trustworthy and reliable machine learning systems. Recent advances in training with auxiliary OOD data demonstrate efficacy in enhancing detection capabilities. Nonetheless, these methods heavily rely on acquiring a large pool of high-quality natural outliers. Some prior methods try to alleviate this problem by synthesizing virtual outliers but suffer from either poor quality or high cost due to the monotonous sampling strategy and the heavy-parameterized generative models. In this paper, we overcome all these problems by proposing the Hamiltonian Monte Carlo Outlier Synthesis (HamOS) framework, which views the synthesis process as sampling from Markov chains. Based solely on the in-distribution data, the Markov chains can extensively traverse the feature space and generate diverse and representative outliers, hence exposing the model to miscellaneous potential OOD scenarios. The Hamiltonian Monte Carlo with sampling acceptance rate almost close to 1 also makes our framework enjoy great efficiency. By empirically competing with SOTA baselines on both standard and large-scale benchmarks, we verify the efficacy and efficiency of our proposed HamOS.
Figures
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Reference graph
Works this paper leans on
-
[1]
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-
[2]
Abhijit Bendale and Terrance E. Boult. Towards open set deep networks. In Proceedings of the 29th IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 1563--1572, 2016
2016
-
[3]
Deep nearest neighbor anomaly detection
Liron Bergman, Niv Cohen, and Yedid Hoshen. Deep nearest neighbor anomaly detection. In Proceedings of the 33rd IEEE Conference on Computer Vision and Pattern Recognition, 2020
2020
-
[4]
representations of knowledge in complex systems
Julian Besag. Comments on “representations of knowledge in complex systems” by u. grenander and mi miller. Journal of the Royal Statistical Society Series B, 56 0 (591-592): 0 4, 1994
1994
-
[5]
On the opportunities and risks of foundation models
Rishi Bommasani, Drew A Hudson, Ehsan Adeli, Russ Altman, Simran Arora, Sydney von Arx, Michael S Bernstein, Jeannette Bohg, Antoine Bosselut, Emma Brunskill, et al. On the opportunities and risks of foundation models. arXiv preprint arXiv:2108.07258, 2021
arXiv 2021
-
[6]
Large-scale machine learning with stochastic gradient descent
L \'e on Bottou. Large-scale machine learning with stochastic gradient descent. In Proceedings of the 19th International Conference on Computational Statistics, pp.\ 177--186. Springer, 2010
2010
-
[7]
Split-ensemble: Efficient ood-aware ensemble via task and model splitting
Anthony Chen, Huanrui Yang, Yulu Gan, Denis A Gudovskiy, Zhen Dong, Haofan Wang, Tomoyuki Okuno, Yohei Nakata, Kurt Keutzer, and Shanghang Zhang. Split-ensemble: Efficient ood-aware ensemble via task and model splitting. In Proceedings of the 41st International Conference on Machine Learning, 2024 a
2024
-
[8]
Tagfog: Textual anchor guidance and fake outlier generation for visual out-of-distribution detection
Jiankang Chen, Tong Zhang, Wei-Shi Zheng, and Ruixuan Wang. Tagfog: Textual anchor guidance and fake outlier generation for visual out-of-distribution detection. In Proceedings of the 38th AAAI Conference on Artificial Intelligence, 2024 b
2024
Show all 111 references
-
[9]
Atom: Robustifying out-of-distribution detection using outlier mining
Jiefeng Chen, Yixuan Li, Xi Wu, Yingyu Liang, and Somesh Jha. Atom: Robustifying out-of-distribution detection using outlier mining. In Proceedings of the 24th European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, pp.\ 430--445, 2021
2021
-
[10]
A simple framework for contrastive learning of visual representations
Ting Chen, Simon Kornblith, Mohammad Norouzi, and Geoffrey Hinton. A simple framework for contrastive learning of visual representations. In Proceedings of the 37th International Conference on Machine Learning, pp.\ 1597--1607, 2020
2020
-
[11]
Cimpoi, S
M. Cimpoi, S. Maji, I. Kokkinos, S. Mohamed, , and A. Vedaldi. Describing textures in the wild. In Proceedings of the Computer Vision and Pattern Recognition, 2014
2014
-
[12]
Distance-based k-nearest neighbors outlier detection method in large-scale traffic data
Taurus T Dang, Henry YT Ngan, and Wei Liu. Distance-based k-nearest neighbors outlier detection method in large-scale traffic data. In Proceedings of the 2015 IEEE International Conference on Digital Signal Processing, pp.\ 507--510. IEEE, 2015
2015
-
[13]
The relationship between precision-recall and roc curves
Jesse Davis and Mark Goadrich. The relationship between precision-recall and roc curves. In Proceedings of the 23rd International Conference on Machine Learning, pp.\ 233--240, 2006
2006
-
[14]
Imagenet: A large-scale hierarchical image database
Jia Deng, Wei Dong, Richard Socher, Li-Jia Li, Kai Li, and Li Fei-Fei. Imagenet: A large-scale hierarchical image database. In Proceedings of the 22nd IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 248--255. Ieee, 2009
2009
-
[15]
The mnist database of handwritten digit images for machine learning research [best of the web]
Li Deng. The mnist database of handwritten digit images for machine learning research [best of the web]. IEEE signal processing magazine, 29 0 (6): 0 141--142, 2012
2012
-
[16]
Extremely simple activation shaping for out-of-distribution detection
Andrija Djurisic, Nebojsa Bozanic, Arjun Ashok, and Rosanne Liu. Extremely simple activation shaping for out-of-distribution detection. In Proceedings of the 11th International Conference on Learning Representations, 2023
2023
-
[17]
Towards unknown-aware learning with virtual outlier synthesis
Xuefeng Du, Zhaoning Wang, Mu Cai, and Sharon Li. Towards unknown-aware learning with virtual outlier synthesis. In Proceedings of the 10th International Conference on Learning Representations, 2022 a
2022
-
[18]
Vos: Learning what you don’t know by virtual outlier synthesis
Xuefeng Du, Zhaoning Wang, Mu Cai, and Yixuan Li. Vos: Learning what you don’t know by virtual outlier synthesis. Proceedings of the 10th International Conference on Learning Representations, 2022 b
2022
-
[19]
Dream the impossible: Outlier imagination with diffusion models
Xuefeng Du, Yiyou Sun, Jerry Zhu, and Yixuan Li. Dream the impossible: Outlier imagination with diffusion models. In Advances in Neural Information Processing Systems 36, 2023
2023
-
[20]
Kennedy, Brian J
Simon Duane, A.D. Kennedy, Brian J. Pendleton, and Duncan Roweth. Hybrid monte carlo. Physics Letters B, 195 0 (2): 0 216--222, 1987
1987
-
[21]
Taming transformers for high-resolution image synthesis
Patrick Esser, Robin Rombach, and Bjorn Ommer. Taming transformers for high-resolution image synthesis. In Proceedings of the 34th IEEE Conference on Computer Vision and Pattern Recognition Workshops, pp.\ 12873--12883, 2021
2021
-
[22]
Detecting hallucinations in large language models using semantic entropy
Sebastian Farquhar, Jannik Kossen, Lorenz Kuhn, and Yarin Gal. Detecting hallucinations in large language models using semantic entropy. Nature, 630 0 (8017): 0 625--630, 2024
2024
-
[23]
An introduction to roc analysis
Tom Fawcett. An introduction to roc analysis. Pattern Recognition Letters, 27 0 (8): 0 861--874, 2006
2006
-
[24]
Dispersion on a sphere
Ronald Aylmer Fisher. Dispersion on a sphere. Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 217 0 (1130): 0 295--305, 1953
1953
-
[25]
Riemann Manifold Langevin and Hamiltonian Monte Carlo Methods
Mark Girolami and Ben Calderhead. Riemann Manifold Langevin and Hamiltonian Monte Carlo Methods . Journal of the Royal Statistical Society Series B: Statistical Methodology, 73 0 (2): 0 123--214, 03 2011
2011
-
[26]
Generative adversarial networks
Ian Goodfellow, Jean Pouget-Abadie, Mehdi Mirza, Bing Xu, David Warde-Farley, Sherjil Ozair, Aaron Courville, and Yoshua Bengio. Generative adversarial networks. Communications of the ACM, 63 0 (11): 0 139--144, 2020
2020
-
[27]
Dense open-set recognition with synthetic outliers generated by real nvp
Matej Grcic, Petra Bevandić, and Sinisa Segvic. Dense open-set recognition with synthetic outliers generated by real nvp. In Proceedings of 16th International Conference on Computer Vision Theory and Applications, pp.\ 133--143, 2021
2021
-
[28]
Overconfidence is key: Verbalized uncertainty evaluation in large language and vision-language models
Tobias Groot and Matias Valdenegro Toro. Overconfidence is key: Verbalized uncertainty evaluation in large language and vision-language models. In Proceedings of the 4th Workshop on Trustworthy Natural Language Processing, 2024
2024
-
[29]
Statistical analysis of nearest neighbor methods for anomaly detection
Xiaoyi Gu, Leman Akoglu, and Alessandro Rinaldo. Statistical analysis of nearest neighbor methods for anomaly detection. In Advances in Neural Information Processing Systems 32, 2019
2019
-
[30]
On a General Method of Expressing the Paths of Light, and of the Planets, by the Coefficients of a Characteristic Function
William Rowan Hamilton. On a General Method of Expressing the Paths of Light, and of the Planets, by the Coefficients of a Characteristic Function. PD Hardy, 1833
-
[31]
Keith Hastings
W. Keith Hastings. Monte carlo sampling methods using markov chains and their applications. Biometrika, 57 0 (1): 0 97--109, 1970
1970
-
[32]
Deep residual learning for image recognition
Kaiming He, Xiangyu Zhang, Shaoqing Ren, and Jian Sun. Deep residual learning for image recognition. In Proceedings of the 29th IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 770--778, 2016
2016
-
[33]
o sch, Jonas L \
Florian Heidecker, Jasmin Breitenstein, Kevin R \"o sch, Jonas L \"o hdefink, Maarten Bieshaar, Christoph Stiller, Tim Fingscheidt, and Bernhard Sick. An application-driven conceptualization of corner cases for perception in highly automated driving. In Proceedings of the 32nd...
2021
-
[34]
Towards corner case detection by modeling the uncertainty of instance segmentation networks
Florian Heidecker, Abdul Hannan, Maarten Bieshaar, and Bernhard Sick. Towards corner case detection by modeling the uncertainty of instance segmentation networks. In Proceedings of the 25th International Conference on Pattern Recognition Workshops, pp.\ 361--374, 2021 b
2021
-
[35]
A baseline for detecting misclassified and out-of-distribution examples in neural networks
Dan Hendrycks and Kevin Gimpel. A baseline for detecting misclassified and out-of-distribution examples in neural networks. In Proceedings of the 5th International Conference on Learning Representations, 2017
2017
-
[36]
Deep anomaly detection with outlier exposure
Dan Hendrycks, Mantas Mazeika, and Thomas Dietterich. Deep anomaly detection with outlier exposure. In Proceedings of the 7th International Conference on Learning Representations, 2019
2019
-
[37]
Scaling out-of-distribution detection for real-world settings
Dan Hendrycks, Steven Basart, Mantas Mazeika, Andy Zou, Joseph Kwon, Mohammadreza Mostajabi, Jacob Steinhardt, and Dawn Song. Scaling out-of-distribution detection for real-world settings. In Proceedings of the 39th International Conference on Machine Learning, volume 162, pp....
2022
-
[38]
Learning probabilistic models from generator latent spaces with hat ebm
Mitch Hill, Erik Nijkamp, Jonathan Mitchell, Bo Pang, and Song-Chun Zhu. Learning probabilistic models from generator latent spaces with hat ebm. In Advances in Neural Information Processing Systems 35, 2022
2022
-
[39]
Denoising diffusion probabilistic models
Jonathan Ho, Ajay Jain, and Pieter Abbeel. Denoising diffusion probabilistic models. In Advances in Neural Information Processing Systems 33, 2020
2020
-
[40]
On the importance of gradients for detecting distributional shifts in the wild
Rui Huang, Andrew Geng, and Yixuan Li. On the importance of gradients for detecting distributional shifts in the wild. In Advances in Neural Information Processing Systems 34, 2021
2021
-
[41]
Estimation of non-normalized statistical models by score matching
Aapo Hyv \"a rinen. Estimation of non-normalized statistical models by score matching. Journal of Machine Learning Research, 6 0 (24): 0 695--709, 2005
2005
-
[42]
DOS : Diverse outlier sampling for out-of-distribution detection
Wenyu Jiang, Hao Cheng, MingCai Chen, Chongjun Wang, and Hongxin Wei. DOS : Diverse outlier sampling for out-of-distribution detection. In Proceedings of the 12th International Conference on Learning Representations, 2024 a
2024
-
[43]
Negative label guided OOD detection with pretrained vision-language models
Xue Jiang, Feng Liu, Zhen Fang, Hong Chen, Tongliang Liu, Feng Zheng, and Bo Han. Negative label guided OOD detection with pretrained vision-language models. In Proceedings of the 12th International Conference on Learning Representations, 2024 b
2024
-
[44]
Cresswell, Anthony L
Hamidreza Kamkari, Brendan Leigh Ross, Jesse C. Cresswell, Anthony L. Caterini, Rahul G. Krishnan, and Gabriel Loaiza-Ganem. A geometric explanation of the likelihood ood detection paradox. In Proceedings of the 41st International Conference on Machine Learning, 2024
2024
-
[45]
Supervised contrastive learning
Prannay Khosla, Piotr Teterwak, Chen Wang, Aaron Sarna, Yonglong Tian, Phillip Isola, Aaron Maschinot, Ce Liu, and Dilip Krishnan. Supervised contrastive learning. In Advances in Neural Information Processing Systems 33, 2020
2020
-
[46]
Neural relation graph: A unified framework for identifying label noise and outlier data
Jang-Hyun Kim, Sangdoo Yun, and Hyun Oh Song. Neural relation graph: A unified framework for identifying label noise and outlier data. Advances in Neural Information Processing Systems 36, 2023
2023
-
[47]
Opengan: Open-set recognition via open data generation
Shu Kong and Deva Ramanan. Opengan: Open-set recognition via open data generation. In Proceedings of the International Conference on Computer Vision, pp.\ 813--822, 2021
2021
-
[48]
Learning multiple layers of features from tiny images
Alex Krizhevsky and Geoffrey Hinton. Learning multiple layers of features from tiny images. Technical Report 0, University of Toronto, 2009
2009
-
[49]
Spherical hamiltonian monte carlo for constrained target distributions
Shiwei Lan, Bo Zhou, and Babak Shahbaba. Spherical hamiltonian monte carlo for constrained target distributions. In Proceedings of the 30th International Conference on Machine Learning, volume 32, pp.\ 629--637, 2013
2013
-
[50]
Tiny imagenet visual recognition challenge
Ya Le and Xuan Yang. Tiny imagenet visual recognition challenge. CS 231N, 7 0 (7): 0 3, 2015
2015
-
[51]
Training confidence-calibrated classifiers for detecting out-of-distribution samples
Kimin Lee, Honglak Lee, Kibok Lee, and Jinwoo Shin. Training confidence-calibrated classifiers for detecting out-of-distribution samples. In Proceedings of the 6th International Conference on Learning Representations, 2018 a
2018
-
[52]
A simple unified framework for detecting out-of-distribution samples and adversarial attacks
Kimin Lee, Kibok Lee, Honglak Lee, and Jinwoo Shin. A simple unified framework for detecting out-of-distribution samples and adversarial attacks. In Advances in Neural Information Processing Systems 31, 2018 b
2018
-
[53]
Reflexive guidance: Improving oodd in vision-language models via self-guided image-adaptive concept generation
Seulbi Lee, Jihyo Kim, and Sangheum Hwang. Reflexive guidance: Improving oodd in vision-language models via self-guided image-adaptive concept generation. arXiv preprint arXiv:2410.14975, 2024
2024 arXiv
-
[54]
Enhancing the reliability of out-of-distribution image detection in neural networks
Shiyu Liang, Yixuan Li, and Rayadurgam Srikant. Enhancing the reliability of out-of-distribution image detection in neural networks. In Proceedings of the 6th International Conference on Learning Representations, 2018
2018
-
[55]
Efficient out-of-distribution detection in digital pathology using multi-head convolutional neural networks
Jasper Linmans, Jeroen van der Laak, and Geert Litjens. Efficient out-of-distribution detection in digital pathology using multi-head convolutional neural networks. In Medical Imaging with Deep Learning, pp.\ 465--478. PMLR, 2020
2020
-
[56]
Fast decision boundary based out-of-distribution detector
Litian Liu and Yao Qin. Fast decision boundary based out-of-distribution detector. In Proceedings of the 41st International Conference on Machine Learning, 2024
2024
-
[57]
Energy-based out-of-distribution detection
Weitang Liu, Xiaoyun Wang, John Owens, and Yixuan Li. Energy-based out-of-distribution detection. In Advances in Neural Information Processing Systems 33, 2020
2020
-
[58]
Neuron activation coverage: Rethinking out-of-distribution detection and generalization
Yibing Liu, Chris XING TIAN, Haoliang Li, Lei Ma, and Shiqi Wang. Neuron activation coverage: Rethinking out-of-distribution detection and generalization. In Proceedings of the 12th International Conference on Learning Representations, 2024
2024
-
[59]
Semantic-aware scene recognition
Alejandro L \'o pez-Cifuentes, Marcos Escudero-Vinolo, Jes \'u s Besc \'o s, and \'A lvaro Garc \' a-Mart \' n. Semantic-aware scene recognition. Pattern Recognition, 102: 0 107256, 2020
2020
-
[60]
SGDR : Stochastic gradient descent with warm restarts
Ilya Loshchilov and Frank Hutter. SGDR : Stochastic gradient descent with warm restarts. In Proceedings of the 5th International Conference on Learning Representations, 2017
2017
-
[61]
Learning with mixture of prototypes for out-of-distribution detection
Haodong Lu, Dong Gong, Shuo Wang, Jason Xue, Lina Yao, and Kristen Moore. Learning with mixture of prototypes for out-of-distribution detection. In Proceedings of the 12th International Conference on Learning Representations, 2024
2024
-
[62]
On the generalised distance in statistics
Prasanta Chandra Mahalanobis. On the generalised distance in statistics. In Proceedings of the 12th National Institute of Science of India, pp.\ 49--55, 1936
1936
-
[63]
Foundations of statistical natural language processing
Christopher Manning and Hinrich Schutze. Foundations of statistical natural language processing. MIT press, 1999
1999
-
[64]
Directional statistics
Kanti V Mardia and Peter E Jupp. Directional statistics. John Wiley and Sons, 2009
2009
-
[65]
Equation of state calculations by fast computing machines
Nicholas Metropolis, Arianna W Rosenbluth, Marshall N Rosenbluth, Augusta H Teller, and Edward Teller. Equation of state calculations by fast computing machines. The journal of chemical physics, 21 0 (6): 0 1087--1092, 1953
1953
-
[66]
Poem: Out-of-distribution detection with posterior sampling
Yifei Ming, Ying Fan, and Yixuan Li. Poem: Out-of-distribution detection with posterior sampling. In Proceedings of the 39th International Conference on Machine Learning, pp.\ 15650--15665, 2022
2022
-
[67]
How to exploit hyperspherical embeddings for out-of-distribution detection? In Proceedings of the 11th International Conference on Learning Representations, 2023 a
Yifei Ming, Yiyou Sun, Ousmane Dia, and Yixuan Li. How to exploit hyperspherical embeddings for out-of-distribution detection? In Proceedings of the 11th International Conference on Learning Representations, 2023 a
2023
-
[68]
How to exploit hyperspherical embeddings for out-of-distribution detection? In Proceedings of the 11th International Conference on Learning Representations, 2023 b
Yifei Ming, Yiyou Sun, Ousmane Dia, and Yixuan Li. How to exploit hyperspherical embeddings for out-of-distribution detection? In Proceedings of the 11th International Conference on Learning Representations, 2023 b
2023
-
[69]
RODEO : Robust outlier detection via exposing adaptive out-of-distribution samples
Hossein Mirzaei, Mohammad Jafari, Hamid Reza Dehbashi, Ali Ansari, Sepehr Ghobadi, Masoud Hadi, Arshia Soltani Moakhar, Mohammad Azizmalayeri, Mahdieh Soleymani Baghshah, and Mohammad Hossein Rohban. RODEO : Robust outlier detection via exposing adaptive out-of-distribution sa...
2024
-
[70]
Coresets for data-efficient training of machine learning models
Baharan Mirzasoleiman, Jeff Bilmes, and Jure Leskovec. Coresets for data-efficient training of machine learning models. In Proceedings of the 37th International Conference on Machine Learning, volume 119, pp.\ 6950--6960, 2020
2020
-
[71]
Unsolvable problem detection: Evaluating trustworthiness of vision language models
Atsuyuki Miyai, Jingkang Yang, Jingyang Zhang, Yifei Ming, Qing Yu, Go Irie, Yixuan Li, Hai Li, Ziwei Liu, and Kiyoharu Aizawa. Unsolvable problem detection: Evaluating trustworthiness of vision language models. arXiv preprint arXiv: 2403.20331, 2024
2024 arXiv
-
[72]
Out-of-distribution detection and generation using soft brownian offset sampling and autoencoders
Felix Moller, Diego Botache, Denis Huseljic, Florian Heidecker, Maarten Bieshaar, and Bernhard Sick. Out-of-distribution detection and generation using soft brownian offset sampling and autoencoders. In Proceedings of the 34th IEEE Conference on Computer Vision and Pattern Rec...
2021
-
[73]
Probabilistic inference using markov chain monte carlo methods
Radford M Neal. Probabilistic inference using markov chain monte carlo methods. Department of Computer Science, University of Toronto Toronto, ON, Canada, 1993
1993
-
[74]
Reading digits in natural images with unsupervised feature learning
Yuval Netzer, Tao Wang, Adam Coates, Alessandro Bissacco, Baolin Wu, Andrew Y Ng, et al. Reading digits in natural images with unsupervised feature learning. In Advances in Neural Information Processing Systems 24 workshop on deep learning and unsupervised feature learning, 2011
2011
-
[75]
Deep neural networks are easily fooled: High confidence predictions for unrecognizable images
Anh Nguyen, Jason Yosinski, and Jeff Clune. Deep neural networks are easily fooled: High confidence predictions for unrecognizable images. In Proceedings of the 28th IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 427--436, 2015
2015
-
[76]
On the powerfulness of textual outlier exposure for visual ood detection
Sangha Park, Jisoo Mok, Dahuin Jung, Saehyung Lee, and Sungroh Yoon. On the powerfulness of textual outlier exposure for visual ood detection. In Advances in Neural Information Processing Systems 36, 2023
2023
-
[77]
Generating high fidelity synthetic data via coreset selection and entropic regularization
Omead Pooladzandi, Pasha Khosravi, Erik Nijkamp, and Baharan Mirzasoleiman. Generating high fidelity synthetic data via coreset selection and entropic regularization. In Advances in Neural Information Processing Systems 36 workshop on synthetic data for empowering ML research, 2023
2023
-
[78]
G2d: Generate to detect anomaly
Masoud Pourreza, Bahram Mohammadi, Mostafa Khaki, Samir Bouindour, Hichem Snoussi, and Mohammad Sabokrou. G2d: Generate to detect anomaly. In Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision, pp.\ 2002--2011, 2021
2002
-
[79]
Remarks on Some Nonparametric Estimates of a Density Function
Murray Rosenblatt. Remarks on Some Nonparametric Estimates of a Density Function . The Annals of Mathematical Statistics, 27 0 (3): 0 832 -- 837, 1956
1956
-
[80]
Ssd: A unified framework for self-supervised outlier detection
Vikash Sehwag, Mung Chiang, and Prateek Mittal. Ssd: A unified framework for self-supervised outlier detection. In Proceedings of the 9th International Conference on Learning Representations, 2021
2021
-
[81]
Scvlm: a vision-language model for driving safety critical event understanding
Liang Shi, Boyu Jiang, and Feng Guo. Scvlm: a vision-language model for driving safety critical event understanding. arXiv preprint arXiv: 2410.00982, 2024
2024 arXiv
-
[82]
Score-based generative modeling through stochastic differential equations
Yang Song, Jascha Sohl-Dickstein, Diederik P Kingma, Abhishek Kumar, Stefano Ermon, and Ben Poole. Score-based generative modeling through stochastic differential equations. In Proceedings of the 9th International Conference on Learning Representations, 2021
2021
-
[83]
Dice: Leveraging sparsification for out-of-distribution detection
Yiyou Sun and Yixuan Li. Dice: Leveraging sparsification for out-of-distribution detection. In Proceedings of the 17th European Conference on Computer Vision, pp.\ 691--708, 2022
2022
-
[84]
React: Out-of-distribution detection with rectified activations
Yiyou Sun, Chuan Guo, and Yixuan Li. React: Out-of-distribution detection with rectified activations. In Advances in Neural Information Processing Systems 34, 2021
2021
-
[85]
Out-of-distribution detection with deep nearest neighbors
Yiyou Sun, Yifei Ming, Xiaojin Zhu, and Yixuan Li. Out-of-distribution detection with deep nearest neighbors. In Proceedings of the 39th International Conference on Machine Learning, volume 162, pp.\ 20827--20840, 2022
2022
-
[86]
Csi: Novelty detection via contrastive learning on distributionally shifted instances
Jihoon Tack, Sangwoo Mo, Jongheon Jeong, and Jinwoo Shin. Csi: Novelty detection via contrastive learning on distributionally shifted instances. In H. Larochelle, M. Ranzato, R. Hadsell, M.F. Balcan, and H. Lin (eds.), Advances in Neural Information Processing Systems 33, 2020
2020
-
[87]
Non-parametric outlier synthesis
Leitian Tao, Xuefeng Du, Jerry Zhu, and Yixuan Li. Non-parametric outlier synthesis. In Proceedings of the 11th International Conference on Learning Representations, 2023
2023
-
[88]
Trust issues: Uncertainty estimation does not enable reliable ood detection on medical tabular data
Dennis Ulmer, Lotta Meijerink, and Giovanni Cin \`a . Trust issues: Uncertainty estimation does not enable reliable ood detection on medical tabular data. In Advances in Neural Information Processing Systems 33 workshop on the machine learning for health, 2020
2020
-
[89]
Visualizing data using t-sne
Laurens van der Maaten and Geoffrey Hinton. Visualizing data using t-sne. Journal of Machine Learning Research, 9 0 (86): 0 2579--2605, 2008
2008
-
[90]
The inaturalist species classification and detection dataset
Grant Van Horn, Oisin Mac Aodha, Yang Song, Yin Cui, Chen Sun, Alex Shepard, Hartwig Adam, Pietro Perona, and Serge Belongie. The inaturalist species classification and detection dataset. In Proceedings of the 31st IEEE Conference on Computer Vision and Pattern Recognition, pp...
2018
-
[91]
Vim: Out-of-distribution with virtual-logit matching
Haoqi Wang, Zhizhong Li, Litong Feng, and Wayne Zhang. Vim: Out-of-distribution with virtual-logit matching. In Proceedings of the 35th IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 4911--4920, 2022
2022
-
[92]
Out-of-distribution detection with implicit outlier transformation
Qizhou Wang, Junjie Ye, Feng Liu, Quanyu Dai, Marcus Kalander, Tongliang Liu, Jianye Hao, and Bo Han. Out-of-distribution detection with implicit outlier transformation. In Proceedings of the 11th International Conference on Learning Representations, 2023
2023
-
[93]
Mitigating neural network overconfidence with logit normalization
Hongxin Wei, Renchunzi Xie, Hao Cheng, Lei Feng, Bo An, and Yixuan Li. Mitigating neural network overconfidence with logit normalization. In Proceedings of the 39th International Conference on Machine Learning, pp.\ 23631--23644, 2022
2022
-
[94]
Bayesian learning via stochastic gradient langevin dynamics
Max Welling and Yee Whye Teh. Bayesian learning via stochastic gradient langevin dynamics. In Proceedings of the 28th International Conference on International Conference on Machine Learning, pp.\ 681–688, 2011
2011
-
[95]
Ledsam, Patricia MacWilliams, Pushmeet Kohli, Alan Karthikesalingam, Simon Kohl, A
Jim Winkens, Rudy Bunel, Abhijit Guha Roy, Robert Stanforth, Vivek Natarajan, Joseph R. Ledsam, Patricia MacWilliams, Pushmeet Kohli, Alan Karthikesalingam, Simon Kohl, A. Taylan Cemgil, S. M. Ali Eslami, and Olaf Ronneberger. Contrastive training for improved out-of-distribut...
2007 arXiv
-
[96]
Sun database: Large-scale scene recognition from abbey to zoo
Jianxiong Xiao, James Hays, Krista A Ehinger, Aude Oliva, and Antonio Torralba. Sun database: Large-scale scene recognition from abbey to zoo. In Proceedings of the 23rd IEEE Conference on Computer Vision and Pattern Recognition, pp.\ 3485--3492, 2010
2010
-
[97]
Scaling for training time and post-hoc out-of-distribution detection enhancement
Kai Xu, Rongyu Chen, Gianni Franchi, and Angela Yao. Scaling for training time and post-hoc out-of-distribution detection enhancement. In Proceedings of the 12th International Conference on Learning Representations, 2024
2024
-
[98]
Lsun: Construction of a large-scale image dataset using deep learning with humans in the loop
Fisher Yu, Ari Seff, Yinda Zhang, Shuran Song, Thomas Funkhouser, and Jianxiong Xiao. Lsun: Construction of a large-scale image dataset using deep learning with humans in the loop. arXiv preprint arXiv:1506.03365, 2015
2015 arXiv
-
[99]
What if the input is expanded in ood detection? In Advances in Neural Information Processing Systems 37, 2024
Boxuan Zhang, Jianing Zhu, Zengmao Wang, Tongliang Liu, Bo Du, and Bo Han. What if the input is expanded in ood detection? In Advances in Neural Information Processing Systems 37, 2024
2024
-
[100]
Mixture outlier exposure: Towards out-of-distribution detection in fine-grained environments
Jingyang Zhang, Nathan Inkawhich, Randolph Linderman, Yiran Chen, and Hai Li. Mixture outlier exposure: Towards out-of-distribution detection in fine-grained environments. In Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision, pp.\ 5531--5540, 2023 a
2023
-
[101]
Openood v1.5: Enhanced benchmark for out-of-distribution detection
Jingyang Zhang, Jingkang Yang, Pengyun Wang, Haoqi Wang, Yueqian Lin, Haoran Zhang, Yiyou Sun, Xuefeng Du, Kaiyang Zhou, Wayne Zhang, Yixuan Li, Ziwei Liu, Yiran Chen, and Hai Li. Openood v1.5: Enhanced benchmark for out-of-distribution detection. In Advances in Neural Informa...
2023
-
[102]
Analysis of knn density estimation
Puning Zhao and Lifeng Lai. Analysis of knn density estimation. IEEE Transactions on Information Theory, 68 0 (12): 0 7971--7995, 2022
2022
-
[103]
Towards optimal feature-shaping methods for out-of-distribution detection
Qinyu Zhao, Ming Xu, Kartik Gupta, Akshay Asthana, Liang Zheng, and Stephen Gould. Towards optimal feature-shaping methods for out-of-distribution detection. In Proceedings of the 12th International Conference on Learning Representations, 2024
2024
-
[104]
Out-of-distribution detection learning with unreliable out-of-distribution sources
Haotian Zheng, Qizhou Wang, Zhen Fang, Xiaobo Xia, Feng Liu, Tongliang Liu, and Bo Han. Out-of-distribution detection learning with unreliable out-of-distribution sources. In Advances in Neural Information Processing Systems 36, 2023
2023
-
[105]
Places: An image database for deep scene understanding
Bolei Zhou, Aditya Khosla, Agata Lapedriza, Antonio Torralba, and Aude Oliva. Places: An image database for deep scene understanding. Journal of Vision, 17 0 (10): 0 296--307, 2017
2017
-
[106]
Exploiting diffusion prior for out-of-distribution detection
Armando Zhu, Jiabei Liu, Li Keqin, Shuying Dai, Bo Hong, Peng Zhao, and Changsong Wei. Exploiting diffusion prior for out-of-distribution detection. Irish Interdisciplinary Journal of Science and Research, 08: 0 171--185, 2024
2024
-
[107]
Unleashing mask: explore the intrinsic out-of-distribution detection capability
Jianing Zhu, Hengzhuang Li, Jiangchao Yao, Tongliang Liu, Jianliang Xu, and Bo Han. Unleashing mask: explore the intrinsic out-of-distribution detection capability. In Proceedings of the 40th International Conference on Machine Learning, 2023 a
2023
-
[108]
Diversified outlier exposure for out-of-distribution detection via informative extrapolation
Jianing Zhu, Geng Yu, Jiangchao Yao, Tongliang Liu, Gang Niu, Masashi Sugiyama, and Bo Han. Diversified outlier exposure for out-of-distribution detection via informative extrapolation. In Advances in Neural Information Processing Systems 36, 2023 b
2023
-
[109]
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