# CSWin-BOAT

This implementation is based on the official implementation of ["CSWin Transformer: A General Vision Transformer Backbone with Cross-Shaped Windows"](https://arxiv.org/pdf/2107.00652.pdf). 

## Requirements

timm==0.3.4, pytorch>=1.4, opencv, ... , run:

```
bash install_req.sh
```

Apex for mixed precision training is used for finetuning. To install apex, run:

```
git clone https://github.com/NVIDIA/apex
cd apex
pip install -v --disable-pip-version-check --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" ./
```

Data prepare: ImageNet with the following folder structure, you can extract imagenet by this [script](https://gist.github.com/BIGBALLON/8a71d225eff18d88e469e6ea9b39cef4).
Please follow the train-test splits of CSwin.

```
│imagenet/
├──train/
│  ├── n01440764
│  │   ├── n01440764_10026.JPEG
│  │   ├── n01440764_10027.JPEG
│  │   ├── ......
│  ├── ......
├──val/
│  ├── n01440764
│  │   ├── ILSVRC2012_val_00000293.JPEG
│  │   ├── ILSVRC2012_val_00002138.JPEG
│  │   ├── ......
│  ├── ......
```

## Train

Train the three lite variants: CSWin-Tiny, CSWin-Small and CSWin-Base:
```
bash train.sh 8 --data <data path> --model CSWin_64_12211_tiny_224 -b 256 --lr 2e-3 --weight-decay .05 --amp --img-size 224 --warmup-epochs 20 --model-ema-decay 0.99984 --drop-path 0.2
```
```
bash train.sh 8 --data <data path> --model CSWin_64_24322_small_224 -b 256 --lr 2e-3 --weight-decay .05 --amp --img-size 224 --warmup-epochs 20 --model-ema-decay 0.99984 --drop-path 0.4
```
```
bash train.sh 8 --data <data path> --model CSWin_96_24322_base_224 -b 128 --lr 1e-3 --weight-decay .1 --amp --img-size 224 --warmup-epochs 20 --model-ema-decay 0.99992 --drop-path 0.5
```

## Pre-trained models

[BOAT-CSwin-Tiny](https://www.dropbox.com/s/rsmtu6r0v2lt0y5/cswin_tiny.pth.tar?dl=0)

[BOAT-CSwin-Small](https://www.dropbox.com/s/cnl00d1faxxoi19/cswin_small.pth.tar?dl=0)

[BOAT-CSwin-Base](https://www.dropbox.com/s/92sr8r8zhng1mqg/cswin_base.pth.tar?dl=0)

## Acknowledgement
This is developped based on CSWin Transformer