Regional Semantic Contrast and Aggregation for Weakly Supervised Semantic Segmentation,
Tianfei Zhou, Meijie Zhang, Fang Zhao, Jianwu Li
CVPR 2022 (arXiv 2203.09653)

Learning semantic segmentation from weakly-labeled (e.g., image tags only) data is challenging since it is hard to infer dense object regions from sparse semantic tags. Despite being broadly studied, most current efforts directly learn from limited semantic annotations carried by individual image or image pairs, and struggle to obtain integral localization maps. Our work alleviates this from a novel perspective, by exploring rich semantic contexts synergistically among abundant weakly-labeled training data for network learning and inference. In particular, we propose regional semantic contrast and aggregation (RCA) . RCA is equipped with a regional memory bank to store massive, diverse object patterns appearing in training data, which acts as strong support for exploration of dataset-level semantic structure. Particularly, we propose i) semantic contrast to drive network learning by contrasting massive categorical object regions, leading to a more holistic object pattern understanding, and ii) semantic aggregation to gather diverse relational contexts in the memory to enrich semantic representations. In this manner, RCA earns a strong capability of fine-grained semantic understanding, and eventually establishes new state-of-the-art results on two popular benchmarks, i.e., PASCAL VOC 2012 and COCO 2014.

We train our model using PyTorch 1.4.0 with four NVIDIA V100 GPUs with 32GB memory per card. Other Python modules can be installed by running

pip install -r requirements.txt

git clone https://github.com/maeve07/RCA

Please download PASCAL VOC 2012 for training, and specify the path of the dataset.

Please run python train.py for training the classification network.

Then generate the pseudo labels of the training set by running python gen_labels.py.

We use Deeplab-v2 for the segmentation network with our generated pseudo labels. But most popular FCN-like segmentation networks can be used instead.

Pseudo labels of PASCAL VOC 2012 train can be downloaded from [Google Drive].

@inproceedings{zhou2022regional,
    author    = {Zhou, Tianfei and Zhang, Meijie and Zhao, Fang and Li, Jianwu},
    title     = {Regional Semantic Contrast and Aggregation for Weakly Supervised Semantic Segmentation},
    booktitle = {CVPR},
    year      = {2022}
}

• Group-Wise Learning for Weakly Supervised Semantic Segmentation (AAAI 2021, TIP 2022) [paper][code]