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

Abstract
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.
Code Repositories
Benchmarks
| Benchmark | Methodology | Metrics |
|---|---|---|
| long-tail-learning-on-cifar-100-lt-r-10 | CBD+TailCalibX | Error Rate: 38.87 |
| long-tail-learning-on-cifar-100-lt-r-100 | CBD+TailCalibX | Error Rate: 53.41 |
| long-tail-learning-on-cifar-100-lt-r-50 | CBD+TailCalibX | Error Rate: 49.1 |
| long-tail-learning-on-mini-imagenet-lt | TailCalibX | Error Rate: 55.27 |
Build AI with AI
From idea to launch — accelerate your AI development with free AI co-coding, out-of-the-box environment and best price of GPUs.