Towards Accurate and Calibrated Classification: Regularizing Cross-Entropy From A Generative Perspective
Summary
Researchers from the University of Pennsylvania introduce Generative Cross-Entropy (GCE), a novel loss function designed to improve both predictive accuracy and calibration in deep neural networks. Modern DNNs often suffer from overconfidence due to overfitting the negative log-likelihood, and while existing solutions like focal loss improve calibration, they typically reduce accuracy. GCE addresses this by maximizing the posterior likelihood $p(xy)$, which is equivalent to cross-entropy augmented with a class-level confidence regularizer. The method is strictly proper under mild conditions and, when combined with an adaptive piecewise temperature scaling (ATS) technique, achieves calibration competitive with focal-loss variants without sacrificing accuracy. Experiments on CIFAR-10/100, Tiny-ImageNet, and a medical imaging benchmark (Tau PET AV1451) demonstrate GCE's consistent improvements in both metrics, especially in long-tailed scenarios, and its negligible computational overhead compared to standard cross-entropy.
Key takeaway
For AI Engineers deploying deep learning models in high-stakes applications like medical diagnosis or autonomous driving, you should consider integrating Generative Cross-Entropy (GCE) into your training pipeline. GCE offers a principled way to achieve better-calibrated confidence estimates and higher predictive accuracy simultaneously, overcoming the traditional trade-off seen with focal loss variants. Your models will be more trustworthy, especially when combined with adaptive temperature scaling, leading to more reliable downstream decision-making.
Key insights
Generative Cross-Entropy improves DNN accuracy and calibration by regularizing class-level confidence from a generative perspective.
Principles
- Strictly proper loss functions are essential for accurate posterior probability estimation.
- Generative models can offer robustness against overfitting compared to discriminative models.
Method
GCE reformulates the training objective to maximize $p(xy)$, equivalent to cross-entropy plus a class-level confidence regularizer. It is complemented by an adaptive piecewise temperature scaling for post-hoc calibration.
In practice
- Use GCE to mitigate overconfidence in DNNs without accuracy trade-offs.
- Combine GCE with adaptive temperature scaling for state-of-the-art calibration.
- Apply GCE in long-tailed datasets for improved robustness and performance.
Topics
- Generative Cross-Entropy
- Model Calibration
- Predictive Accuracy
- Deep Neural Networks
- Adaptive Temperature Scaling
Best for: AI Engineer, Computer Vision Engineer, Research Scientist, AI Scientist, Machine Learning Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.