Focal Transformer
This is the official implementation of our Focal Transformer -- "Focal Self-attention for Local-Global Interactions in Vision Transformers", by Jianwei Yang, Chunyuan Li, Pengchuan Zhang, Xiyang Dai, Bin Xiao, Lu Yuan and Jianfeng Gao.
Introduction
Our Focal Transfomer introduced a new self-attention mechanism called focal self-attention for vision transformers. In this new mechanism, each token attends the closest surrounding tokens at fine granularity but the tokens far away at coarse granularity, and thus can capture both short- and long-range visual dependencies efficiently and effectively.
With our Focal Transformers, we achieved superior performance over the state-of-the-art vision Transformers on a range of public benchmarks. In particular, our Focal Transformer models with a moderate size of 51.1M and a larger size of 89.8M achieve 83.6 and 84.0
Top-1 accuracy, respectively, on ImageNet classification at 224x224 resolution. Using Focal Transformers as the backbones, we obtain consistent and substantial improvements over the current state-of-the-art methods for 6 different object detection methods trained with standard 1x and 3x schedules. Our largest Focal Transformer yields 58.7/58.9 box mAPs
and 50.9/51.3 mask mAPs
on COCO mini-val/test-dev, and 55.4 mIoU
on ADE20K for semantic segmentation.
Benchmarking
ImageNet-1K
Image Classification onModel | Pretrain | Use Conv | Resolution | [email protected] | [email protected] | #params | FLOPs | Checkpoint | Config |
---|---|---|---|---|---|---|---|---|---|
Focal-T | IN-1K | No | 224 | 82.2 | 95.9 | 28.9M | 4.9G | download | yaml |
Focal-T | IN-1K | Yes | 224 | 82.7 | 96.1 | 30.8M | 4.9G | download | yaml |
Focal-S | IN-1K | No | 224 | 83.6 | 96.2 | 51.1M | 9.4G | download | yaml |
Focal-B | IN-1K | No | 224 | 84.0 | 96.5 | 89.8M | 16.4G | download | yaml |
COCO
Object Detection and Instance Segmentation onMask R-CNN
Backbone | Pretrain | Lr Schd | #params | FLOPs | box mAP | mask mAP |
---|---|---|---|---|---|---|
Focal-T | ImageNet-1K | 1x | 49M | 291G | 44.8 | 41.0 |
Focal-T | ImageNet-1K | 3x | 49M | 291G | 47.2 | 42.7 |
Focal-S | ImageNet-1K | 1x | 71M | 401G | 47.4 | 42.8 |
Focal-S | ImageNet-1K | 3x | 71M | 401G | 48.8 | 43.8 |
Focal-B | ImageNet-1K | 1x | 110M | 533G | 47.8 | 43.2 |
Focal-B | ImageNet-1K | 3x | 110M | 533G | 49.0 | 43.7 |
RetinaNet
Backbone | Pretrain | Lr Schd | #params | FLOPs | box mAP |
---|---|---|---|---|---|
Focal-T | ImageNet-1K | 1x | 39M | 265G | 43.7 |
Focal-T | ImageNet-1K | 3x | 39M | 265G | 45.5 |
Focal-S | ImageNet-1K | 1x | 62M | 367G | 45.6 |
Focal-S | ImageNet-1K | 3x | 62M | 367G | 47.3 |
Focal-B | ImageNet-1K | 1x | 101M | 514G | 46.3 |
Focal-B | ImageNet-1K | 3x | 101M | 514G | 46.9 |
Other detection methods
Backbone | Pretrain | Method | Lr Schd | #params | FLOPs | box mAP |
---|---|---|---|---|---|---|
Focal-T | ImageNet-1K | Cascade Mask R-CNN | 3x | 87M | 770G | 51.5 |
Focal-T | ImageNet-1K | ATSS | 3x | 37M | 239G | 49.5 |
Focal-T | ImageNet-1K | RepPointsV2 | 3x | 45M | 491G | 51.2 |
Focal-T | ImageNet-1K | Sparse R-CNN | 3x | 111M | 196G | 49.0 |
ADE20K
Semantic Segmentation onBackbone | Pretrain | Method | Resolution | Iters | #params | FLOPs | mIoU | mIoU (MS) |
---|---|---|---|---|---|---|---|---|
Focal-T | ImageNet-1K | UPerNet | 512x512 | 160k | 62M | 998G | 45.8 | 47.0 |
Focal-S | ImageNet-1K | UPerNet | 512x512 | 160k | 85M | 1130G | 48.0 | 50.0 |
Focal-B | ImageNet-1K | UPerNet | 512x512 | 160k | 126M | 1354G | 49.0 | 50.5 |
Focal-L | ImageNet-22K | UPerNet | 640x640 | 160k | 240M | 3376G | 54.0 | 55.4 |
Getting Started
- Please follow get_started_for_image_classification.md to get started for image classification.
- Please follow get_started_for_object_detection.md to get started for object detection.
- Please follow get_started_for_semantic_segmentation.md to get started for semantic segmentation.
Citation
If you find this repo useful to your project, please consider to cite it with following bib:
@misc{yang2021focal,
title={Focal Self-attention for Local-Global Interactions in Vision Transformers},
author={Jianwei Yang and Chunyuan Li and Pengchuan Zhang and Xiyang Dai and Bin Xiao and Lu Yuan and Jianfeng Gao},
year={2021},
eprint={2107.00641},
archivePrefix={arXiv},
primaryClass={cs.CV}
}
Acknowledgement
Our codebase is built based on Swin-Transformer. We thank the authors for the nicely organized code!
Contributing
This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.
When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.
Trademarks
This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.