Semantically Contrastive Learning for Low-light Image Enhancement
Here, we propose an effective semantically contrastive learning paradigm for Low-light image enhancement (namely SCL-LLE). Beyond the existing LLE wisdom, it casts the image enhancement task as multi-task joint learning, where LLE is converted into three constraints of contrastive learning, semantic brightness consistency, and feature preservation for simultaneously ensuring the exposure, texture, and color consistency. SCL-LLE allows the LLE model to learn from unpaired positives (normal-light)/negatives (over/underexposed), and enables it to interact with the scene semantics to regularize the image enhancement network, yet the interaction of high-level semantic knowledge and the low-level signal prior is seldom investigated in previous methods.
Network
- Overall architecture of our proposed SCL-LLE. It includes a low-light image enhancement network, a contrastive learning module and a semantic segmentation module.
Experiment
PyTorch implementation of SCL-LLE
Requirements
- Python 3.7
- PyTorch 1.4.0
- opencv
- torchvision
- numpy
- pillow
- scikit-learn
- tqdm
- matplotlib
- visdom
SCL-LLE does not need special configurations. Just basic environment.
Folder structure
The following shows the basic folder structure.
├── datasets
│ ├── data
│ │ ├── cityscapes
│ │ └── Contrast
| ├── test_data
│ ├── cityscapes.py
| └── util.py
├── network # semantic segmentation model
├── lowlight_test.py # low-light image enhancement testing code
├── train.py # training code
├── lowlight_model.py
├── Myloss.py
├── checkpoints
│ ├── best_deeplabv3plus_mobilenet_cityscapes_os16.pth # A pre-trained semantic segmentation model
│ ├── LLE_model.pth # A pre-trained SCL-LLE model
Test
- cd SCL-LLE
python lowlight_test.py
The script will process the images in the sub-folders of "test_data" folder and make a new folder "result" in the "datasets". You can find the enhanced images in the "result" folder.
Train
- cd SCL-LLE
- download the Cityscapes dataset
- download the cityscapes training data google drive and contrast training data google drive
- unzip and put the downloaded "train" folder and "Contrast" folder to "datasets/data/cityscapes/leftImg8bit" folder and "datasets/data" folder
- download the pre-trained semantic segmentation model and put it to "checkpoints" folder
python train.py
Contact
If you have any question, please contact liling@nuaa.edu.cn