Decision boundaries and convex hulls in the feature space that deep learning functions learn from images
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Abstract (arXiv)
The success of deep neural networks in image classification and learning can be partly attributed to the features they extract from images. It is often speculated about the properties of a low-dimensional manifold that models extract and learn from images. However, there is not sufficient understanding about this low-dimensional space based on theory or empirical evidence. For image classification models, their last hidden layer is the one where images of each class is separated from other classes and it also has the least number of features. Here, we develop methods and formulations to study that feature space for any model. We study the partitioning of the domain in feature space, identify regions guaranteed to have certain classifications, and investigate its implications for the pixel space. We observe that geometric arrangements of decision boundaries in feature space is significantly different compared to pixel space, providing insights about adversarial vulnerabilities, image morphing, extrapolation, ambiguity in classification, and the mathematical understanding of image classification models.
Key facts. Cited by 5 papers in the map (data through 7 Oct 2026). Builds on 25 of its 42 references that are in the map. First posted on arXiv 5 Feb 2022.
Builds on
25 of 42 references.
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13 more
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Citing papers per year: 2022: 1; 2023: 3; 2024: 0; 2025: 1.
5 papers.
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- 2023Scalable Attribution of Adversarial Attacks via Multi-Task Learningcited by 2
- 2025SHRUG-FM: Reliability-Aware Foundation Models for Earth Observationcited by 2
- 2022Over-parameterization: A Necessary Condition for Models that Extrapolatecited by 1
- 2023An Ambiguity Measure for Recognizing the Unknowns in Deep Learningcited by 1
- 2025SHRUG-FM: Reliability-Aware Foundation Models for Earth Observation13 Nov 2025
- 2023An Ambiguity Measure for Recognizing the Unknowns in Deep Learning11 Dec 2023
- 2023Scalable Attribution of Adversarial Attacks via Multi-Task Learning25 Feb 2023
- 2023Reverse engineering adversarial attacks with fingerprints from adversarial examples31 Jan 2023
- 2022Over-parameterization: A Necessary Condition for Models that Extrapolate20 Mar 2022