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Vision Transformer

An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale

Abstract

While the Transformer architecture has become the de-facto standard for natural language processing tasks, its applications to computer vision remain limited. In vision, attention is either applied in conjunction with convolutional networks, or used to replace certain components of convolutional networks while keeping their overall structure in place. We show that this reliance on CNNs is not necessary and a pure transformer applied directly to sequences of image patches can perform very well on image classification tasks. When pre-trained on large amounts of data and transferred to multiple mid-sized or small image recognition benchmarks (ImageNet, CIFAR-100, VTAB, etc.), Vision Transformer (ViT) attains excellent results compared to state-of-the-art convolutional networks while requiring substantially fewer computational resources to train.

Results and models

The training step of Vision Transformers is divided into two steps. The first step is training the model on a large dataset, like ImageNet-21k, and get the pre-trained model. And the second step is training the model on the target dataset, like ImageNet-1k, and get the fine-tuned model. Here, we provide both pre-trained models and fine-tuned models.

ImageNet-21k

The pre-trained models on ImageNet-21k are used to fine-tune, and therefore don’t have evaluation results.

Model	resolution	Params(M)	Flops(G)	Download
ViT-B16*	224x224	86.86	33.03	model
ViT-B32*	224x224	88.30	8.56	model
ViT-L16*	224x224	304.72	116.68	model

Models with * are converted from the official repo.

ImageNet-1k

Model	Pretrain	resolution	Params(M)	Flops(G)	Top-1 (%)	Top-5 (%)	Config	Download
ViT-B16*	ImageNet-21k	384x384	86.86	33.03	85.43	97.77	config	model
ViT-B32*	ImageNet-21k	384x384	88.30	8.56	84.01	97.08	config	model
ViT-L16*	ImageNet-21k	384x384	304.72	116.68	85.63	97.63	config	model
ViT-B16 (IPU)	ImageNet-21k	224x224	86.86	33.03	81.22	95.56	config	model | log

Models with * are converted from the official repo. The config files of these models are only for validation. We don’t ensure these config files’ training accuracy and welcome you to contribute your reproduction results.

Citation

@inproceedings{
  dosovitskiy2021an,
  title={An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale},
  author={Alexey Dosovitskiy and Lucas Beyer and Alexander Kolesnikov and Dirk Weissenborn and Xiaohua Zhai and Thomas Unterthiner and Mostafa Dehghani and Matthias Minderer and Georg Heigold and Sylvain Gelly and Jakob Uszkoreit and Neil Houlsby},
  booktitle={International Conference on Learning Representations},
  year={2021},
  url={https://openreview.net/forum?id=YicbFdNTTy}
}