README.md

BatchFormer: Learning to Explore Sample Relationships for Robust Representation Learning

Introduction

This is the official PyTorch implementation of BatchFormer for Long-Tailed Recognition, Domain Generalization, Compositional Zero-Shot Learning, Contrastive Learning.

Sample Relationship Exploration for Robust Representation Learning

Please also refer to BatchFormerV2, in which we introduce a BatchFormerV2 module for vision Transformers.

Main Results

Long-Tailed Recognition

ImageNet-LT

	All(R10)	Many(R10)	Med(R10)	Few(R10)	All(R50)	Many(R50)	Med(R50)	Few(R50)
RIDE(3 experts)[1]	44.7	57.0	40.3	25.5	53.6	64.9	50.4	33.2
+BatchFormer	45.7	56.3	42.1	28.3	54.1	64.3	51.4	35.1
PaCo[2]	-	-	-	-	57.0	64.8	55.9	39.1
+BatchFormer	-	-	-	-	57.4	62.7	56.7	42.1

Here, we demonstrate the result on one-stage RIDE (ResNext-50)

	All	Many	Medium	Few
RIDE(3 experts)*	55.9	67.3	52.8	34.6
+BatchFormer	56.5	66.6	54.2	36.0

iNaturalist 2018

	All	Many	Medium	Few
RIDE(3 experts)	72.5	68.1	72.7	73.2
+BatchFormer	74.1	65.5	74.5	75.8

Object Detection (V2)

	AP	AP50	AP75	APS	APM	APL	Model
DETR	34.8	55.6	35.8	14.0	37.2	54.6
+BatchFormerV2	36.9	57.9	38.5	15.6	40.0	55.9	download
Conditional DETR	40.9	61.8	43.3	20.8	44.6	59.2
+BatchFormerV2	42.3	63.2	45.1	21.9	46.0	60.7	download
Deformable DETR	43.8	62.6	47.7	26.4	47.1	58.0
+BatchFormerV2	45.5	64.3	49.8	28.3	48.6	59.4	download

The backbone is ResNet-50. The training epoch is 50.

Panoptic segmentation (V2)

	PQ	SQ	RQ	PQ(th)	SQ(th)	RQ(th)	PQ(st)	SQ(st)	RQ(st)	AP
DETR	43.4	79.3	53.8	48.2	79.8	59.5	36.3	78.5	45.3	31.1
+BatchFormerV2	45.1	80.3	55.3	50.5	81.1	61.5	37.1	79.1	46.0	33.4

Contrastive Learning

	Epochs	Top-1	Pretrained
MoCo-v2[3]	200	67.5
+BatchFormer	200	68.4	download
MoCo-v3[4]	100	68.9
+BatchFormer	100	70.1	download

Here, we provide the pretrained MoCo-V3 model corresponding to this strategy.

Domain Generalization

ResNet-18

	PACS	VLCS	OfficeHome	Terra
SWAD[5]	82.9	76.3	62.1	42.1
+BatchFormer	83.7	76.9	64.3	44.8

Compositional Zero-Shot Learning

	MIT-States(AUC)	MIT-States(HM)	UT-Zap50K(AUC)	UT-Zap50K(HM)	C-GQA(AUC)	C-GQA(HM)
CGE*[6]	6.3	20.0	31.5	46.5	3.7	14.9
+BatchFormer	6.7	20.6	34.6	49.0	3.8	15.5

Few-Shot Learning

Experiments on CUB.

	Unseen	Seen	Harmonic mean
CUB[7]*	67.5	65.1	66.3
+BatchFormer	68.2	65.8	67.0

Image Classification (V2)

	Top-1	Top-5
DeiT-T	72.2	91.1
+BatchFormerV2	72.7	91.5
DeiT-S	79.8	95.0
+BatchFormerV2	80.4	95.2
DeiT-B	81.7	95.5
+BatchFormerV2	82.2	95.8

Reference

1. Long-tailed recognition by routing diverse distribution-aware experts. In ICLR, 2021
2. Parametric contrastive learning. In ICCV, 2021
3. Improved baselines with momentum contrastive learning.
4. An empirical study of training self-supervised vision transformers. In CVPR, 2021
5. Domain generalization by seeking flat minima. In NeurIPS, 2021.
6. Learning graph embeddings for compositional zero-shot learning. In CVPR, 2021
7. Contrastive learning based hybrid networks for long- tailed image classification. In CVPR, 2021

PyTorch Code

The proposed BatchFormer can be implemented with a few lines as follows,

def BatchFormer(x, y, encoder, is_training):
    # x: input features with the shape [N, C]
    # encoder: TransformerEncoderLayer(C,4,C,0.5)
    if not is_training:
        return x, y
    pre_x = x
    x = encoder(x.unsqueeze(1)).squeeze(1)
    x = torch.cat([pre_x, x], dim=0)
    y = torch.cat([y, y], dim=0)
    return x, y

Citation

If you find this repository helpful, please consider cite:

@inproceedings{hou2022batch,
    title={BatchFormer: Learning to Explore Sample Relationships for Robust Representation Learning},
    author={Hou, Zhi and Yu, Baosheng and Tao, Dacheng},
    booktitle={CVPR},
    year={2022}
}
@article{hou2022batchformerv2,
   title={BatchFormerV2: Exploring Sample Relationships for Dense Representation Learning},
   author={Hou, Zhi and Yu, Baosheng and Wang, Chaoyue and Zhan, Yibing and Tao, Dacheng},
   journal={arXiv preprint arXiv:2204.01254},
   year={2022}
}

Feel free to contact "zhou9878 at uni dot sydney dot edu dot au" if you have any questions.