Proceedings

Semantic Geometric Calibration in Randomized Neural Feature Space

Download BibTeX Cite

Proceedings of the Thirty-Fifth International Joint Conference on Artificial Intelligence. Main Track. Pages 4116-4124.

https://doi.org/10.24963/ijcai.2026/458

Abstract

Modern neural networks can be accurate yet poorly calibrated. We present Random Geometric Calibration (RGC), a post hoc method that augments confidence estimation with a geometric signal derived from distances to training data in an aggregated semantic representation space. Prior geometric calibration methods in feature space often rely on architecture-specific layer choices, which can be unstable across models and datasets. To avoid this dependence, RGC samples a fixed number of intermediate blocks uniformly at random and reuses this set at both calibration and test time.

We instantiate RGC with RGCL, which applies spatial pyramid pooling to each sampled activation, projects features to a fixed dimension, and computes a nearest-neighbor separation score that is mapped to probabilities via isotonic regression.

We also present RGCC, which replaces pooling and projection with uniform coordinate sampling for improved computational efficiency.

We evaluate RGCL and RGCC across multiple datasets, including CIFAR-10, CIFAR-100, and Tiny-ImageNet, and across a diverse set of architectures such as ResNet, DenseNet, and DINOv2. Our results show that RGCL achieves state-of-the-art or near state-of-the-art calibration performance, reducing expected calibration error by approximately 78% on average and by up to 97% for some models.

Finally, we provide representation analysis that explains why RGCL and RGCC succeed without layer selection and characterize their computational overheads. We observe that layers exhibiting favorable geometric structure tend to emerge in later network blocks, and that randomized aggregation implicitly emphasizes these layers, leading to robust and reliable calibration performance.

  1. [Benkert et al., 2024] Ryan Benkert, Mohit Prabhushankar, and Ghassan AlRegib. Transitional uncertainty with lay- ered intermediate predictions. In Ruslan Salakhutdinov, Zico Kolter, Katherine A. Heller, Adrian Weller, Nuria Oliver, Jonathan Scarlett, and Felix Berkenkamp, editors, Forty-first International Conference on Machine Learning, ICML 2024, Vienna, Austria, July 21-27, 2024, Proceed- ings of Machine Learning Research, pages 3484-3505. PMLR / OpenReview.net, 2024.
  2. [Caruana and Niculescu-Mizil, 2006] Rich Caruana and Alexandru Niculescu-Mizil. An empirical comparison of supervised learning algorithms. In William W. Cohen and Andrew W. Moore, editors, Machine Learning, Proceed- ings of the Twenty-Third International Conference (ICML 2006), Pittsburgh, Pennsylvania, USA, June 25-29, 2006, ACM International Conference Proceeding Series, pages 161-168. ACM, 2006.
  3. [Chouraqui et al., 2022] Gabriella Chouraqui, Liron Cohen, Gil Einziger, and Liel Leman. A geometric method for improved uncertainty estimation in real-time. In James Cussens and Kun Zhang, editors, Uncertainty in Artificial Intelligence, Proceedings of the Thirty-Eighth Conference on Uncertainty in Artificial Intelligence, UAI 2022, 1-5 August 2022, Eindhoven, The Netherlands, Proceedings of Machine Learning Research, pages 422-432. PMLR, 2022.
  4. [Gal and Ghahramani, 2016] Yarin Gal and Zoubin Ghahra- mani. Dropout as a Bayesian approximation: Repre- senting model uncertainty in deep learning. In Maria- Florina Balcan and Kilian Q. Weinberger, editors, Pro- ceedings of the 33rd International Conference on Machine Learning, ICML 2016, New York City, NY, USA, June 19- 24, 2016, JMLR Workshop and Conference Proceedings, pages 1050-1059. JMLR.org, 2016.
  5. [Guo et al., 2017] Chuan Guo, Geoff Pleiss, Yu Sun, and Kilian Q. Weinberger. On calibration of modern neural networks. In Doina Precup and Yee Whye Teh, editors, Proceedings of the 34th International Conference on Ma- chine Learning, ICML 2017, Sydney, NSW, Australia, 6-11 August 2017, Proceedings of Machine Learning Research, pages 1321-1330. PMLR, 2017.
  6. [Gupta and Ramdas, 2021] Chirag Gupta and Aaditya Ram- das. Distribution-free calibration guarantees for histogram binning without sample splitting. In Marina Meila and Tong Zhang, editors, Proceedings of the 38th International Conference on Machine Learning, ICML 2021, 18-24 July 2021, Virtual Event, Proceedings of Machine Learning Re- search, pages 3942-3952. PMLR, 2021.
  7. [Gupta and Ramdas, 2022] Chirag Gupta and Aaditya Ram- das. Top-label calibration and multiclass-to-binary reduc- tions. In The Tenth International Conference on Learning Representations, ICLR 2022, Virtual Event, April 25-29, 2022. OpenReview.net, 2022.
  8. [He et al., 2015] Kaiming He, Xiangyu Zhang, Shaoqing Ren, and Jian Sun. Spatial pyramid pooling in deep con- volutional networks for visual recognition. IEEE Trans. Pattern Anal. Mach. Intell., 37(9):1904-1916, 2015.
  9. [He et al., 2016] Kaiming He, Xiangyu Zhang, Shaoqing Ren, and Jian Sun. Deep residual learning for image recog- nition. In 2016 IEEE Conference on Computer Vision and Pattern Recognition, CVPR 2016, Las Vegas, NV, USA, June 27-30, 2016, pages 770-778. IEEE Computer Soci- ety, 2016.
  10. [Hendrycks et al., 2019] Dan Hendrycks, Kimin Lee, and Mantas Mazeika. Using pre-training can improve model robustness and uncertainty. In Kamalika Chaudhuri and Ruslan Salakhutdinov, editors, Proceedings of the 36th In- ternational Conference on Machine Learning, ICML 2019, 9-15 June 2019, Long Beach, California, USA, Proceed- ings of Machine Learning Research, pages 2712-2721.
  11. PMLR, 2019.
  12. [Huang et al., 2017] Gao Huang, Zhuang Liu, Laurens van der Maaten, and Kilian Q. Weinberger. Densely con- nected convolutional networks. In 2017 IEEE Conference on Computer Vision and Pattern Recognition, CVPR 2017, Honolulu, HI, USA, July 21-26, 2017, pages 2261-2269. IEEE Computer Society, 2017.
  13. [Jiang et al., 2018] Heinrich Jiang, Been Kim, Melody Y. Guan, and Maya R. Gupta. To trust or not to trust a classifier. In Samy Bengio, Hanna M. Wallach, Hugo Larochelle, Kristen Grauman, Nicolò Cesa-Bianchi, and Roman Garnett, editors, Advances in Neural Information Processing Systems 31: Annual Conference on Neural In- formation Processing Systems 2018, NeurIPS 2018, De- cember 3-8, 2018, Montréal, Canada, pages 5546-5557, 2018.
  14. [Krizhevsky, 2009] Alex Krizhevsky. Learning multiple lay- ers of features from tiny images. Technical report, Univer- sity of Toronto, 2009.
  15. [Kull et al., 2017] Meelis Kull, Telmo de Menezes e Silva Filho, and Peter A. Flach. Beta calibration: a well- founded and easily implemented improvement on logistic calibration for binary classifiers. In Aarti Singh and Xiao- jin (Jerry) Zhu, editors, Proceedings of the 20th Interna- tional Conference on Artificial Intelligence and Statistics, AISTATS 2017, 20-22 April 2017, Fort Lauderdale, FL, USA, Proceedings of Machine Learning Research, pages 623-631. PMLR, 2017.
  16. [Kull et al., 2019] Meelis Kull, Miquel Perelló-Nieto, Markus Kängsepp, Telmo de Menezes e Silva Filho, Hao Song, and Peter A. Flach. Beyond temperature scaling: Obtaining well-calibrated multi-class probabilities with Dirichlet calibration. In Hanna M. Wallach, Hugo Larochelle, Alina Beygelzimer, Florence d'Alché-Buc, Emily B. Fox, and Roman Garnett, editors, Advances in Neural Information Processing Systems 32: Annual Conference on Neural Information Processing Systems 2019, NeurIPS 2019, December 8-14, 2019, Vancouver, BC, Canada, pages 12295-12305, 2019.
  17. [Lakshminarayanan et al., 2017] Balaji Lakshminarayanan, Alexander Pritzel, and Charles Blundell. Simple and scalable predictive uncertainty estimation using deep en- sembles. In Isabelle Guyon, Ulrike von Luxburg, Samy Bengio, Hanna M. Wallach, Rob Fergus, S. V. N. Vish- wanathan, and Roman Garnett, editors, Advances in Neu- ral Information Processing Systems 30: Annual Confer- ence on Neural Information Processing Systems 2017, De- cember 4-9, 2017, Long Beach, CA, USA, pages 6402- 6413, 2017.
  18. [Le and Yang, 2015] Ya Le and Xuan Yang. Tiny ImageNet visual recognition challenge, 2015. Stanford University CS231n Course Project.
  19. [Lee et al., 2018] Kimin Lee, Kibok Lee, Honglak Lee, and Jinwoo Shin. A simple unified framework for detect- ing out-of-distribution samples and adversarial attacks.
  20. In Samy Bengio, Hanna M. Wallach, Hugo Larochelle, Kristen Grauman, Nicolò Cesa-Bianchi, and Roman Gar- nett, editors, Advances in Neural Information Processing Systems 31: Annual Conference on Neural Information Processing Systems 2018, NeurIPS 2018, December 3-8, 2018, Montréal, Canada, pages 7167-7177, 2018.
  21. [Loshchilov and Hutter, 2017] Ilya Loshchilov and Frank Hutter. SGDR: stochastic gradient descent with warm restarts. In 5th International Conference on Learning Rep- resentations, ICLR 2017, Toulon, France, April 24-26, 2017, Conference Track Proceedings. OpenReview.net, 2017.
  22. [Mandelbaum and Weinshall, 2017] Amit Mandelbaum and Daphna Weinshall. Distance-based confidence score for neural network classifiers. CoRR, abs/1709.09844, 2017.
  23. [Nanda et al., 2023] Vedant Nanda, Till Speicher, John P. Dickerson, Krishna P. Gummadi, Soheil Feizi, and Adrian Weller. Diffused redundancy in pre-trained representa- tions. In Alice Oh, Tristan Naumann, Amir Globerson, Kate Saenko, Moritz Hardt, and Sergey Levine, editors, Advances in Neural Information Processing Systems 36: Annual Conference on Neural Information Processing Sys- tems 2023, NeurIPS 2023, New Orleans, LA, USA, Decem- ber 10 -16, 2023, 2023.
  24. [Nixon et al., 2019] Jeremy Nixon, Michael W. Dusenberry, Linchuan Zhang, Ghassen Jerfel, and Dustin Tran. Mea- suring calibration in deep learning. In Uncertainty and Ro- bustness in Deep Visual Learning Workshop, CVPR 2019, Long Beach, CA, USA, June 17, 2019, 2019.
  25. [Oquab et al., 2024] Maxime Oquab, Timothée Darcet, Théo Moutakanni, et al. DINOv2: Learning robust visual fea- tures without supervision. Trans. Mach. Learn. Res., 2024.
  26. [Papernot and McDaniel, 2018] Nicolas Papernot and Patrick D. McDaniel. Deep k-nearest neighbors: Towards confident, interpretable and robust deep learning. CoRR, abs/1803.04765, 2018.
  27. [Platt, 2000] John C. Platt. Probabilistic outputs for sup- port vector machines and comparisons to regularized like- lihood methods. In Alexander J. Smola, Peter L. Bartlett, Bernhard Schölkopf, and Dale Schuurmans, editors, Ad- vances in Large Margin Classifiers, pages 61-74. MIT Press, Cambridge, MA, 2000.
  28. [Schuirmann, 1987] Donald J Schuirmann. A comparison of the two one-sided tests procedure and the power ap- proach for assessing the equivalence of average bioavail- ability. Journal of pharmacokinetics and biopharmaceu- tics, 15(6):657-680, 1987.
  29. [Thulasidasan et al., 2019] Sunil Thulasidasan, Gopinath Chennupati, Jeff A. Bilmes, Tanmoy Bhattacharya, and Sarah Michalak. On Mixup training: Improved calibra- tion and predictive uncertainty for deep neural networks. In Hanna M. Wallach, Hugo Larochelle, Alina Beygelz- imer, Florence d'Alché-Buc, Emily B. Fox, and Roman Garnett, editors, Advances in Neural Information Process- ing Systems 32: Annual Conference on Neural Information Processing Systems 2019, NeurIPS 2019, December 8-14, 2019, Vancouver, BC, Canada, pages 13888-13899, 2019.
  30. [Tomani et al., 2023] Christian Tomani, Futa Kai Waseda, Yuesong Shen, and Daniel Cremers. Beyond in-domain scenarios: Robust density-aware calibration. In Andreas Krause, Emma Brunskill, Kyunghyun Cho, Barbara En- gelhardt, Sivan Sabato, and Jonathan Scarlett, editors, In- ternational Conference on Machine Learning, ICML 2023, 23-29 July 2023, Honolulu, Hawaii, USA, Proceedings of Machine Learning Research, pages 34344-34368. PMLR, 2023.
  31. [Xiong et al., 2023] Miao Xiong, Ailin Deng, Pang Wei W. Koh, Jiaying Wu, Shen Li, Jianqing Xu, and Bryan Hooi. Proximity-informed calibration for deep neural networks. In Alice Oh, Tristan Naumann, Amir Globerson, Kate Saenko, Moritz Hardt, and Sergey Levine, editors, Ad- vances in Neural Information Processing Systems 36: An- nual Conference on Neural Information Processing Sys- tems 2023, NeurIPS 2023, New Orleans, LA, USA, De- cember 10 -16, 2023, 2023.
  32. [Yüksekgönül et al., 2023] Mert Yüksekgönül, Linjun Zhang, James Y. Zou, and Carlos Guestrin. Beyond confidence: Reliable models should also consider atypi- cality. In Alice Oh, Tristan Naumann, Amir Globerson, Kate Saenko, Moritz Hardt, and Sergey Levine, editors, Advances in Neural Information Processing Systems 36: Annual Conference on Neural Information Processing Systems 2023, NeurIPS 2023, New Orleans, LA, USA, December 10 -16, 2023, 2023.
  33. [Zadrozny and Elkan, 2002] Bianca Zadrozny and Charles Elkan. Transforming classifier scores into accurate mul- ticlass probability estimates. In Proceedings of the Eighth ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, July 23-26, 2002, Edmonton, Alberta, Canada, pages 694-699. ACM, 2002.
  34. [Zhang and Haghani, 2015] Yanru Zhang and Ali Haghani. A gradient boosting method to improve travel time predic- tion. Transportation Research Part C-emerging Technolo- gies, 58:308-324, 2015.

References were extracted automatically from the PDF and may contain errors.

Welcome Future Conferences AI Journal Division IJCAI Proceedings About IJCAI IJCAI Awards