by Binhui Xie, Longhui Yuan, Shuang Li, Chi Harold Liu and Xinjing Cheng

[Arxiv] [Paper]

🥳 We are happy to announce that RIPU was accepted at CVPR22 Oral Presentation.

We propose a simple region-based active learning approach for semantic segmentation under a domain shift, aiming to automatically query a small partition of image regions to be labeled while maximizing segmentation performance.

Our algorithm, Region Impurity and Prediction Uncertainty (RIPU), introduces a new acquisition strategy characterizing the spatial adjacency of image regions along with the prediction confidence. We show that the proposed region-based selection strategy makes more efficient use of a limited budget than image-based or point-based counterparts.

We show some qualitative examples from the Cityscapes validation set,

and also visualize the queried regions to annotate.

For more information on DAFormer, please check our [Paper].

If you find this project useful in your research, please consider citing:

@InProceedings{Xie_2022_CVPR,
    author    = {Xie, Binhui and Yuan, Longhui and Li, Shuang and Liu, Chi Harold and Cheng, Xinjing},
    title     = {Towards Fewer Annotations: Active Learning via Region Impurity and Prediction Uncertainty for Domain Adaptive Semantic Segmentation},
    booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
    month     = {June},
    year      = {2022},
    pages     = {8068-8078}
}

• Python 3.7
• Pytorch 1.7.1
• torchvision 0.8.2

Step-by-step installation

conda create --name ADASeg -y python=3.7
conda activate ADASeg

# this installs the right pip and dependencies for the fresh python
conda install -y ipython pip

# this installs required packages
pip install -r requirements.txt

• Download The Cityscapes Dataset, The GTAV Dataset, and The SYNTHIA Dataset

The data folder should be structured as follows:

├── datasets/
│   ├── cityscapes/     
|   |   ├── gtFine/
|   |   ├── leftImg8bit/
│   ├── gtav/
|   |   ├── images/
|   |   ├── labels/
|   |   ├── gtav_label_info.p
│   └──	synthia
|   |   ├── RAND_CITYSCAPES/
|   |   ├── synthia_label_info.p
│   └──	

Symlink the required dataset

ln -s /path_to_cityscapes_dataset datasets/cityscapes
ln -s /path_to_gtav_dataset datasets/gtav
ln -s /path_to_synthia_dataset datasets/synthia

Generate the label static files for GTAV/SYNTHIA Datasets by running

python datasets/generate_gtav_label_info.py -d datasets/gtav -o datasets/gtav/
python datasets/generate_synthia_label_info.py -d datasets/synthia -o datasets/synthia/

We provide the training scripts in scripts/ using single GPU.

# training for GTAV to Cityscapes
sh gtav_to_cityscapes.sh

# training for SYNTHIA to Cityscapes
sh synthia_to_cityscapes.sh

python test.py -cfg configs/gtav/deeplabv3plus_r101_RA.yaml resume results/v3plus_gtav_ra_5.0_precent/model_iter040000.pth OUTPUT_DIR results/v3plus_gtav_ra_5.0_precent

This project is based on the following open-source projects. We thank their authors for making the source code publically available.

• FADA
• SDCA

If you have any problem about our code, feel free to contact

• [email protected]

or describe your problem in Issues.