Papers › Feature Generation for Long-tail Classification

Feature Generation for Long-tail Classification

10 Nov 2021arXiv:2111.05956archive 2025-07-28

Rahul Vigneswaran, Marc T. Law, Vineeth N. Balasubramanian, Makarand Tapaswi

The visual world naturally exhibits an imbalance in the number of object or scene instances resulting in a \emph{long-tailed distribution}. This imbalance poses significant challenges for classification models based on deep learning. Oversampling instances of the tail classes attempts to solve this imbalance. However, the limited visual diversity results in a network with poor representation ability. A simple counter to this is decoupling the representation and classifier networks and using oversampling only to train the classifier. In this paper, instead of repeatedly re-sampling the same image (and thereby features), we explore a direction that attempts to generate meaningful features by estimating the tail category's distribution. Inspired by ideas from recent work on few-shot learning, we create calibrated distributions to sample additional features that are subsequently used to train the classifier. Through several experiments on the CIFAR-100-LT (long-tail) dataset with varying imbalance factors and on mini-ImageNet-LT (long-tail), we show the efficacy of our approach and establish a new state-of-the-art. We also present a qualitative analysis of generated features using t-SNE visualizations and analyze the nearest neighbors used to calibrate the tail class distributions. Our code is available at https://github.com/rahulvigneswaran/TailCalibX.

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Tasks

ClassificationFew-Shot LearningGeneral ClassificationLong-tail Learningimbalanced classification

Datasets

Introduced by this paper, per the archive.

mini-ImageNet-LT

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Long-tail Learning CIFAR-100-LT (ρ=10) CBD+TailCalibX Error Rate 38.87 #25 of 31 Archive leaderboard report
Long-tail Learning CIFAR-100-LT (ρ=100) CBD+TailCalibX Error Rate 53.41 #42 of 66 Archive leaderboard report
Long-tail Learning CIFAR-100-LT (ρ=50) CBD+TailCalibX Error Rate 49.1 #22 of 25 Archive leaderboard report
Long-tail Learning mini-ImageNet-LT TailCalibX Error Rate 55.27 #1 of 1 Archive leaderboard report

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