Space Engage: Collaborative Space Supervision for Contrastive-based Semi-Supervised Semantic Segmentation (ICCV 2023)

cover figure.pdf

This repository contains the code of CSS from the paper: Space Engage: Collaborative Space Supervision for Contrastive-based Semi-Supervised Semantic Segmentation

In this paper, we propose a novel apporach to use the pseudo-labels from the logit and representation space in a collabrative way. Meanwhile, we use the softmax similarity as the indicator to tilt training in representation space.

Updates

Sep. 2023 -- Upload the code.

Prepare

CSS is evaluated with two datasets: PASCAL VOC 2012 and CityScapes.

For PASCAL VOC, please download the original training images from the official PASCAL site: VOCtrainval_11-May-2012.tar and the augmented labels here: SegmentationClassAug.zip. Extract the folder JPEGImages and SegmentationClassAug as follows:
```
├── data
│   ├── VOCdevkit
│   │   ├──VOC2012
│   │   |   ├──JPEGImages
│   │   |   ├──SegmentationClassAug
```
For CityScapes, please download the original images and labels from the official CityScapes site: leftImg8bit_trainvaltest.zip and gtFine_trainvaltest.zip. Extract the folder leftImg8bit_trainvaltest.zip and gtFine_trainvaltest.zip as follows:
```
├── data
│   ├── cityscapes
│   │   ├──leftImg8bit
│   │   |   ├──train
│   │   |   ├──val
│   │   ├──train
│   │   ├──val
```
Folders train and val under leftImg8bit contains training and validation images while folders train and val under leftImg8bit contains labels.

The data split folder of VOC and CityScapes is as follows:

├── VOC(CityScapes)_split
│   ├── labeled number
│   │   ├──seed
│   │   |   ├──labeled_filename.txt
│   │   |   ├──unlabeled_filename.txt
│   │   |   ├──valid_filename.txt

You need to change the name of folders (labeled number and seed) according to your actual experiments.

CSS uses ResNet-101 pretrained on ImageNet and ResNet-101 with deep stem block, please download from here for ResNet-101 and here for ResNet-101 stem. Remember to change the directory in corresponding python file.

In order to install the correct environment, please run the following script:

conda create -n css_env python=3.8.5
conda activate css_env
pip install -r requirements.txt

It may takes a long time, take a break and have a cup of coffee! It is OK if you want to install environment manually, remember to check CAREFULLY!

Run

You can run our code with multiple GPUs.

For our baseline, please run the following script:
```
python ori_pseudo.py
```
For the mix label strategy, please run the following script:
```
python mix_label.py
```

For the cross label strategy, please run the following script:

python cross_label.py

The seed in our experiments is 3407. You can change the label rate and seed as you like, remember to change the corresponding config files and data_split directory.

Hyper-parameters

Some critical hyper-parameters used in the code are shown below:	Name	Discription
`alpha_t`	update speed of teacher model	`0.99`
`alpha_p`	update speed of prototypes	`0.99`
`un_threshold`	threshold in unsupervised loss	`0.97`
`weak_threshold`	weak threshold in contrastive loss	`0.7`
`strong_threshold`	strong threshold in contrastive loss	`0.8`
`temp`	temperature in contrastive loss	`0.5`
`num_queries`	number of queries in contrastive loss	`256`
`num_negatives`	number of negatives in contrastive loss	`512`
`warm_up`	warm up epochs if is needed	`20`

Acknowledgement

The data processing and augmentation (CutMix, CutOut, and ClassMix) are borrowed from ReCo.

ReCo: https://github.com/lorenmt/reco

Thanks a lot for their splendid work!

Citation

If you think this work is useful for you and your research, please considering citing the following:

@article{wang2023space,
  title={Space Engage: Collaborative Space Supervision for Contrastive-based Semi-Supervised Semantic Segmentation},
  author={Wang, Changqi and Xie, Haoyu and Yuan, Yuhui and Fu, Chong and Yue, Xiangyu},
  journal={arXiv preprint arXiv:2307.09755},
  year={2023}
}

Contact

If you have any questions or meet any problems, please feel free to contact us.

Changqi Wang, wangchangqi98@gmail.com

WangChangqi98 / CSS

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