# ISNet

[ISNet: Integrate Image-Level and Semantic-Level Context for Semantic Segmentation](https://arxiv.org/pdf/2108.12382.pdf)

## Description

This is an implementation of [ISNet](https://arxiv.org/pdf/2108.12382.pdf).
[Official Repo](https://github.com/SegmentationBLWX/sssegmentation)

## Usage

### Prerequisites

- Python 3.7
- PyTorch 1.6 or higher
- [MIM](https://github.com/open-mmlab/mim) v0.33 or higher
- [MMSegmentation](https://github.com/open-mmlab/mmsegmentation) v1.0.0rc2 or higher

All the commands below rely on the correct configuration of `PYTHONPATH`, which should point to the project's directory so that Python can locate the module files. In `isnet/` root directory, run the following line to add the current directory to `PYTHONPATH`:

```shell
export PYTHONPATH=`pwd`:$PYTHONPATH
```

### Training commands

```shell
mim train mmsegmentation configs/isnet_r50-d8_8xb2-160k_cityscapes-512x1024.py --work-dir work_dirs/isnet
```

To train on multiple GPUs, e.g. 8 GPUs, run the following command:

```shell
mim train mmsegmentation configs/isnet_r50-d8_8xb2-160k_cityscapes-512x1024.py --work-dir work_dirs/isnet --launcher pytorch --gpus 8
```

### Testing commands

```shell
mim test mmsegmentation configs/isnet_r50-d8_8xb2-160k_cityscapes-512x1024.py --work-dir work_dirs/isnet --checkpoint ${CHECKPOINT_PATH}
```

| Method | Backbone | Crop Size | Lr schd | Mem (GB) | Inf time (fps) |  mIoU | mIoU(ms+flip) | config                                                          | download                                                                                                                 |
| ------ | -------- | --------- | ------: | -------- | -------------- | ----: | ------------: | --------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ |
| ISNet  | R-50-D8  | 512x1024  |       - | -        | -              | 79.32 |         80.88 | [config](configs/isnet_r50-d8_8xb2-160k_cityscapes-512x1024.py) | [model](https://download.openmmlab.com/mmsegmentation/v0.5/isnet/isnet_r50-d8_cityscapes-512x1024_20230104-a7a8ccf2.pth) |

## Citation

```bibtex
@article{Jin2021ISNetII,
  title={ISNet: Integrate Image-Level and Semantic-Level Context for Semantic Segmentation},
  author={Zhenchao Jin and B. Liu and Qi Chu and Nenghai Yu},
  journal={2021 IEEE/CVF International Conference on Computer Vision (ICCV)},
  year={2021},
  pages={7169-7178}
}
```

## Checklist

The progress of ISNet.

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- [x] Milestone 1: PR-ready, and acceptable to be one of the `projects/`.

  - [x] Finish the code

  <!-- The code's design shall follow existing interfaces and convention. For example, each model component should be registered into `mmseg.registry.MODELS` and configurable via a config file. -->

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  - [x] Test-time correctness

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  - [ ] Training-time correctness

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  - [ ] Type hints and docstrings

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  - [ ] Metafile.yml

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- [ ] Move your modules into the core package following the codebase's file hierarchy structure.

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