Rethinking Few-Shot Image Classification: a Good Embedding Is All You Need?
About
The focus of recent meta-learning research has been on the development of learning algorithms that can quickly adapt to test time tasks with limited data and low computational cost. Few-shot learning is widely used as one of the standard benchmarks in meta-learning. In this work, we show that a simple baseline: learning a supervised or self-supervised representation on the meta-training set, followed by training a linear classifier on top of this representation, outperforms state-of-the-art few-shot learning methods. An additional boost can be achieved through the use of self-distillation. This demonstrates that using a good learned embedding model can be more effective than sophisticated meta-learning algorithms. We believe that our findings motivate a rethinking of few-shot image classification benchmarks and the associated role of meta-learning algorithms. Code is available at: http://github.com/WangYueFt/rfs/.
Related benchmarks
| Task | Dataset | Result | Rank | |
|---|---|---|---|---|
| Image Classification | ImageNet 1k (test) | Top-1 Accuracy55.9 | 798 | |
| Image Classification | STL-10 (test) | Accuracy95 | 357 | |
| Image Classification | Stanford Cars (test) | Accuracy70 | 306 | |
| Few-shot classification | tieredImageNet (test) | Accuracy84.41 | 282 | |
| Few-shot Image Classification | Mini-Imagenet (test) | -- | 235 | |
| Image Classification | FGVC-Aircraft (test) | Accuracy36 | 231 | |
| 5-way Classification | miniImageNet (test) | -- | 231 | |
| Image Classification | MiniImagenet | Accuracy79.64 | 206 | |
| Image Classification | DTD (test) | Accuracy64.3 | 181 | |
| Few-shot classification | Mini-ImageNet | 1-shot Acc64.8 | 175 |