/GSS

[CVPR 2023] Official repository of Generative Semantic Segmentation

Primary LanguagePython

Generative Semantic Segmentation

Generative Semantic Segmentation,
Jiaqi Chen, Jiachen Lu, Xiatian Zhu, and Li Zhang
CVPR 2023

Abstract

We present Generative Semantic Segmentation (GSS), a generative framework for semantic segmentation. Unlike previous methods addressing a per-pixel classification problem, we cast semantic segmentation into an image-conditioned mask generation problem. This is achieved by replacing the conventional per-pixel discriminative learning with a latent prior learning process. Specifically, we model the variational posterior distribution of latent variables given the segmentation mask. This is done by expressing the segmentation mask with a special type of image (dubbed as maskige). This posterior distribution allows to generate segmentation masks unconditionally. To implement semantic segmentation, we further introduce a conditioning network (e.g., an encoder-decoder Transformer) optimized by minimizing the divergence between the posterior distribution of maskige (i.e. segmentation masks) and the latent prior distribution of input images on the training set. Extensive experiments on standard benchmarks show that our GSS can perform competitively to prior art alternatives in the standard semantic segmentation setting, whilst achieving a new state of the art in the more challenging cross-domain setting.

GSS

Results

Cityscapes dataset

Name Backbone Iterations mIoU mAcc Config checkpoint
GSS-FF R101 80k 77.76 85.9 config google drive
GSS-FF Swin-L 80k 78.90 87.03 config google drive
GSS-FT-W ResNet 80k 78.46 85.92 config google drive
GSS-FT-W Swin-L 80k 80.05 87.32 config google drive

ADE20K dataset

Name Backbone Iterations mIoU mAcc Config checkpoint
GSS-FF Swin-L 160k 46.29 57.84 config google drive
GSS-FT-W Swin-L 160k 48.54 58.94 config google drive

MSeg dataset

Name Backbone Iterations h.mean Config checkpoint
GSS-FF HRNet-W48 160k 52.60 config google drive
GSS-FF Swin-L 160k 59.49 config google drive
GSS-FT-W HRNet-W48 160k 55.20 config google drive
GSS-FT-W Swin-L 160k 61.94 config google drive

Get Started

Intall

This implementation is build upon mmsegmentation. please follow the steps in INSTALL.md to prepare the environment.

Data

Please follow the steps in DATA.md to prepare the dataset.

Train

The training process is divided into three stages:

  1. latent posterior learning of $\mathcal{X}$;
  2. latent prior learning (Train GSS-FF);
  3. latent posterior learning of $\mathcal{X}^{-1}$ (Train GSS-FT-W).

See TRAIN.md for more information.

Eval

Please download the pre-trained model weights and put them in the ./<ckp_dir> folder. We provide the following scripts to evaluate GSS.

bash tools/dist_test.sh ${CONFIG_FILE} ${CHECKPOINT_FILE} ${GPU_NUM} --eval mIoU

For example, to evaluate the GSS-FF model on Cityscapes dataset, run:

# test with 8 GPUs
bash tools/dist_test.sh configs/gss/cityscapes/gss-ff_r101_768x768_80k_cityscapes.py ./<ckp_dir>/gss-ff_swin-l_768x768_80k_cityscapes_iter_80000.pth 8 --eval mIoU

Reference

@inproceedings{chen2023generative,
  title={Generative Semantic Segmentation
  author={Chen, Jiaqi and Lu, Jiachen and Zhu, Xiatian and Zhang, Li},
  booktitle={Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition},
  year={2023}
}