Papers › PolyLoss: A Polynomial Expansion Perspective of Classification Loss Functions

PolyLoss: A Polynomial Expansion Perspective of Classification Loss Functions

26 Apr 2022ICLR 2022 4arXiv:2204.12511archive 2025-07-28

Zhaoqi Leng, Mingxing Tan, Chenxi Liu, Ekin Dogus Cubuk, Xiaojie Shi, Shuyang Cheng, Dragomir Anguelov

Cross-entropy loss and focal loss are the most common choices when training deep neural networks for classification problems. Generally speaking, however, a good loss function can take on much more flexible forms, and should be tailored for different tasks and datasets. Motivated by how functions can be approximated via Taylor expansion, we propose a simple framework, named PolyLoss, to view and design loss functions as a linear combination of polynomial functions. Our PolyLoss allows the importance of different polynomial bases to be easily adjusted depending on the targeting tasks and datasets, while naturally subsuming the aforementioned cross-entropy loss and focal loss as special cases. Extensive experimental results show that the optimal choice within the PolyLoss is indeed dependent on the task and dataset. Simply by introducing one extra hyperparameter and adding one line of code, our Poly-1 formulation outperforms the cross-entropy loss and focal loss on 2D image classification, instance segmentation, object detection, and 3D object detection tasks, sometimes by a large margin.

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Code

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19 repositories listed; official and paper-mentioned ones first.

abhuse/polyloss-pytorch mentioned on GitHubpytorchMIT report
frgfm/Holocron mentioned on GitHubpytorch report
jahongir7174/MaskRCNN mentioned on GitHubpytorchMIT report
jahongir7174/PolyLoss mentioned on GitHubpytorchMIT report
lumia-group/apl mentioned on GitHubpytorchMIT report
nachiket273/loss-tryout mentioned on GitHubpytorchMIT report
yiyixuxu/polyloss-pytorch mentioned on GitHubpytorch report
pwc-1/Paper-9 mindspore report

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to_one_hot yiyixuxu/polyloss-pytorch/PolyLoss.py community (archive-listed) ran · fixture could not drive it no licence file found · pointer only · 6806c813ec675aab · report
crossentropyfirstn nachiket273/loss-tryout/polynloss.py community (archive-listed) unverified MIT (permissive) · f6b1da081133f2de · report
focallossfirstn nachiket273/loss-tryout/polynloss.py community (archive-listed) unverified MIT (permissive) · 75f93a5098113ec2 · report
polynloss nachiket273/loss-tryout/polynloss.py community (archive-listed) unverified MIT (permissive) · f31e8ddcecd510f0 · report
resize jahongir7174/MaskRCNN/utils/util.py community (archive-listed) unverified MIT (permissive) · e6a94a5bc4d9e8f4 · report
xy2wh jahongir7174/MaskRCNN/utils/util.py community (archive-listed) unverified MIT (permissive) · 9ead510a24af1caa · report
xyn2xy jahongir7174/MaskRCNN/utils/util.py community (archive-listed) unverified MIT (permissive) · e79b32bd70ec5c58 · report

Tasks

3D Object DetectionImage ClassificationInstance SegmentationObject DetectionSemantic Segmentationimage-classification

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Image Classification ImageNet EfficientNetV2 (PolyLoss) Top 1 Accuracy 87.2% #99 of 1060 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

Focal Loss

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