Papers › Focal Self-attention for Local-Global Interactions in Vision Transformers

Focal Self-attention for Local-Global Interactions in Vision Transformers

1 Jul 2021arXiv:2107.00641archive 2025-07-28

Jianwei Yang, Chunyuan Li, Pengchuan Zhang, Xiyang Dai, Bin Xiao, Lu Yuan, Jianfeng Gao

Recently, Vision Transformer and its variants have shown great promise on various computer vision tasks. The ability of capturing short- and long-range visual dependencies through self-attention is arguably the main source for the success. But it also brings challenges due to quadratic computational overhead, especially for the high-resolution vision tasks (e.g., object detection). In this paper, we present focal self-attention, a new mechanism that incorporates both fine-grained local and coarse-grained global interactions. Using 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 focal self-attention, we propose a new variant of Vision Transformer models, called Focal Transformer, which achieves superior performance over the state-of-the-art vision Transformers on a range of public image classification and object detection benchmarks. In particular, our Focal Transformer models with a moderate size of 51.1M and a larger size of 89.8M achieve 83.5 and 83.8 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 Swin Transformers 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, creating new SoTA on three of the most challenging computer vision tasks.

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Tasks

Image ClassificationInstance SegmentationObject DetectionSemantic Segmentationimage-classificationobject-detection

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Instance Segmentation COCO minival Focal-L (HTC++, multi-scale) mask AP 50.9 #21 of 93 Archive leaderboard report
Instance Segmentation COCO test-dev Focal-L (HTC++, multi-scale) AP50 75.4 #19 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev Focal-L (HTC++, multi-scale) AP75 56.5 #19 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev Focal-L (HTC++, multi-scale) APL 64.2 #19 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev Focal-L (HTC++, multi-scale) APS 35.6 #19 of 112 Archive leaderboard report
Instance Segmentation COCO test-dev Focal-L (HTC++, multi-scale) mask AP 51.3 #19 of 112 Archive leaderboard report
Object Detection COCO minival Focal-L (DyHead, multi-scale) AP50 77.2 #33 of 220 Archive leaderboard report
Object Detection COCO minival Focal-L (DyHead, multi-scale) APL 73.4 #33 of 220 Archive leaderboard report
Object Detection COCO minival Focal-L (DyHead, multi-scale) box AP 58.7 #33 of 220 Archive leaderboard report
Object Detection COCO test-dev Focal-L (DyHead, multi-scale) box mAP 58.9 #33 of 225 Archive leaderboard report
Semantic Segmentation ADE20K Focal-L (UperNet, ImageNet-22k pretrain) Validation mIoU 55.40 #47 of 235 Archive leaderboard report
Semantic Segmentation ADE20K val Focal-L (UperNet, ImageNet-22k pretrain) mIoU 55.4 #30 of 95 Archive leaderboard report

Ranks are positions in the archive's leaderboards as they stood at the 2025-07-28 snapshot. Results published since then are not among these rows, so a rank here is not a current standing.

Methods

Introduced by this paper: Focal Transformers

Absolute Position EncodingsAdamAttentionBPEDense ConnectionsDropoutFocal TransformersLabel SmoothingLayer NormalizationLinear LayerMulti-Head AttentionPosition-Wise Feed-Forward LayerResidual ConnectionSoftmaxTransformerVision Transformer

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