mmseg.md

# MMSegmentation Deployment

- [MMSegmentation Deployment](#mmsegmentation-deployment)
  - [Installation](#installation)
    - [Install mmseg](#install-mmseg)
    - [Install mmdeploy](#install-mmdeploy)
  - [Convert model](#convert-model)
  - [Model specification](#model-specification)
  - [Model inference](#model-inference)
    - [Backend model inference](#backend-model-inference)
    - [SDK model inference](#sdk-model-inference)
  - [Supported models](#supported-models)
  - [Reminder](#reminder)

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[MMSegmentation](https://github.com/open-mmlab/mmsegmentation/tree/main) aka `mmseg` is an open source semantic segmentation toolbox based on PyTorch. It is a part of the [OpenMMLab](https://openmmlab.com/) project.

## Installation

### Install mmseg

Please follow the [installation guide](https://mmsegmentation.readthedocs.io/en/latest/get_started.html) to install mmseg.

### Install mmdeploy

There are several methods to install mmdeploy, among which you can choose an appropriate one according to your target platform and device.

**Method I:** Install precompiled package

You can refer to [get_started](https://mmdeploy.readthedocs.io/en/latest/get_started.html#installation)

**Method II:** Build using scripts

If your target platform is **Ubuntu 18.04 or later version**, we encourage you to run
[scripts](../01-how-to-build/build_from_script.md). For example, the following commands install mmdeploy as well as inference engine - `ONNX Runtime`.

```shell
git clone --recursive -b main https://github.com/open-mmlab/mmdeploy.git
cd mmdeploy
python3 tools/scripts/build_ubuntu_x64_ort.py $(nproc)
export PYTHONPATH=$(pwd)/build/lib:$PYTHONPATH
export LD_LIBRARY_PATH=$(pwd)/../mmdeploy-dep/onnxruntime-linux-x64-1.8.1/lib/:$LD_LIBRARY_PATH
```

**NOTE**:

- Adding `$(pwd)/build/lib` to `PYTHONPATH` is for importing mmdeploy SDK python module - `mmdeploy_runtime`, which will be presented in chapter [SDK model inference](#sdk-model-inference).
- When [inference onnx model by ONNX Runtime](#backend-model-inference), it requests ONNX Runtime library be found. Thus, we add it to `LD_LIBRARY_PATH`.

**Method III:** Build from source

If neither **I** nor **II** meets your requirements, [building mmdeploy from source](../01-how-to-build/build_from_source.md) is the last option.

## Convert model

You can use [tools/deploy.py](https://github.com/open-mmlab/mmdeploy/tree/main/tools/deploy.py) to convert mmseg models to the specified backend models. Its detailed usage can be learned from [here](https://github.com/open-mmlab/mmdeploy/tree/main/docs/en/02-how-to-run/convert_model.md#usage).

The command below shows an example about converting `unet` model to onnx model that can be inferred by ONNX Runtime.

```shell
cd mmdeploy

# download unet model from mmseg model zoo
mim download mmsegmentation --config unet-s5-d16_fcn_4xb4-160k_cityscapes-512x1024 --dest .

# convert mmseg model to onnxruntime model with dynamic shape
python tools/deploy.py \
    configs/mmseg/segmentation_onnxruntime_dynamic.py \
    unet-s5-d16_fcn_4xb4-160k_cityscapes-512x1024.py \
    fcn_unet_s5-d16_4x4_512x1024_160k_cityscapes_20211210_145204-6860854e.pth \
    demo/resources/cityscapes.png \
    --work-dir mmdeploy_models/mmseg/ort \
    --device cpu \
    --show \
    --dump-info
```

It is crucial to specify the correct deployment config during model conversion. We've already provided builtin deployment config [files](https://github.com/open-mmlab/mmdeploy/tree/main/configs/mmseg) of all supported backends for mmsegmentation. The config filename pattern is:

```
segmentation_{backend}-{precision}_{static | dynamic}_{shape}.py
```

- **{backend}:** inference backend, such as onnxruntime, tensorrt, pplnn, ncnn, openvino, coreml etc.
- **{precision}:** fp16, int8. When it's empty, it means fp32
- **{static | dynamic}:** static shape or dynamic shape
- **{shape}:** input shape or shape range of a model

Therefore, in the above example, you can also convert `unet` to other backend models by changing the deployment config file `segmentation_onnxruntime_dynamic.py` to [others](https://github.com/open-mmlab/mmdeploy/tree/main/configs/mmseg), e.g., converting to tensorrt-fp16 model by `segmentation_tensorrt-fp16_dynamic-512x1024-2048x2048.py`.

```{tip}
When converting mmseg models to tensorrt models, --device should be set to "cuda"
```

## Model specification

Before moving on to model inference chapter, let's know more about the converted model structure which is very important for model inference.

The converted model locates in the working directory like `mmdeploy_models/mmseg/ort` in the previous example. It includes:

```
mmdeploy_models/mmseg/ort
├── deploy.json
├── detail.json
├── end2end.onnx
└── pipeline.json
```

in which,

- **end2end.onnx**: backend model which can be inferred by ONNX Runtime
- \***.json**: the necessary information for mmdeploy SDK

The whole package **mmdeploy_models/mmseg/ort** is defined as **mmdeploy SDK model**, i.e., **mmdeploy SDK model** includes both backend model and inference meta information.

## Model inference

### Backend model inference

Take the previous converted `end2end.onnx` model as an example, you can use the following code to inference the model and visualize the results.

```python
from mmdeploy.apis.utils import build_task_processor
from mmdeploy.utils import get_input_shape, load_config
import torch

deploy_cfg = 'configs/mmseg/segmentation_onnxruntime_dynamic.py'
model_cfg = './unet-s5-d16_fcn_4xb4-160k_cityscapes-512x1024.py'
device = 'cpu'
backend_model = ['./mmdeploy_models/mmseg/ort/end2end.onnx']
image = './demo/resources/cityscapes.png'

# read deploy_cfg and model_cfg
deploy_cfg, model_cfg = load_config(deploy_cfg, model_cfg)

# build task and backend model
task_processor = build_task_processor(model_cfg, deploy_cfg, device)
model = task_processor.build_backend_model(backend_model)

# process input image
input_shape = get_input_shape(deploy_cfg)
model_inputs, _ = task_processor.create_input(image, input_shape)

# do model inference
with torch.no_grad():
    result = model.test_step(model_inputs)

# visualize results
task_processor.visualize(
    image=image,
    model=model,
    result=result[0],
    window_name='visualize',
    output_file='./output_segmentation.png')
```

### SDK model inference

You can also perform SDK model inference like following,

```python
from mmdeploy_runtime import Segmentor
import cv2
import numpy as np

img = cv2.imread('./demo/resources/cityscapes.png')

# create a classifier
segmentor = Segmentor(model_path='./mmdeploy_models/mmseg/ort', device_name='cpu', device_id=0)
# perform inference
seg = segmentor(img)

# visualize inference result
## random a palette with size 256x3
palette = np.random.randint(0, 256, size=(256, 3))
color_seg = np.zeros((seg.shape[0], seg.shape[1], 3), dtype=np.uint8)
for label, color in enumerate(palette):
  color_seg[seg == label, :] = color
# convert to BGR
color_seg = color_seg[..., ::-1]
img = img * 0.5 + color_seg * 0.5
img = img.astype(np.uint8)
cv2.imwrite('output_segmentation.png', img)
```

Besides python API, mmdeploy SDK also provides other FFI (Foreign Function Interface), such as C, C++, C#, Java and so on. You can learn their usage from [demos](https://github.com/open-mmlab/mmdeploy/tree/main/demo).

## Supported models

| Model                                                                                                     | TorchScript | OnnxRuntime | TensorRT | ncnn | PPLNN | OpenVino |
| :-------------------------------------------------------------------------------------------------------- | :---------: | :---------: | :------: | :--: | :---: | :------: |
| [FCN](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/fcn)                                 |      Y      |      Y      |    Y     |  Y   |   Y   |    Y     |
| [PSPNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/pspnet)[\*](#static_shape)        |      Y      |      Y      |    Y     |  Y   |   Y   |    Y     |
| [DeepLabV3](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/deeplabv3)                     |      Y      |      Y      |    Y     |  Y   |   Y   |    Y     |
| [DeepLabV3+](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/deeplabv3plus)                |      Y      |      Y      |    Y     |  Y   |   Y   |    Y     |
| [Fast-SCNN](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/fastscnn)[\*](#static_shape)   |      Y      |      Y      |    Y     |  N   |   Y   |    Y     |
| [UNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/unet)                               |      Y      |      Y      |    Y     |  Y   |   Y   |    Y     |
| [ANN](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/ann)[\*](#static_shape)              |      Y      |      Y      |    Y     |  N   |   N   |    N     |
| [APCNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/apcnet)                           |      Y      |      Y      |    Y     |  Y   |   N   |    N     |
| [BiSeNetV1](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/bisenetv1)                     |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [BiSeNetV2](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/bisenetv2)                     |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [CGNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/cgnet)                             |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [DMNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/dmnet)                             |      ?      |      Y      |    N     |  N   |   N   |    N     |
| [DNLNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/dnlnet)                           |      ?      |      Y      |    Y     |  Y   |   N   |    Y     |
| [EMANet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/emanet)                           |      Y      |      Y      |    Y     |  N   |   N   |    Y     |
| [EncNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/encnet)                           |      Y      |      Y      |    Y     |  N   |   N   |    Y     |
| [ERFNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/erfnet)                           |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [FastFCN](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/fastfcn)                         |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [GCNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/gcnet)                             |      Y      |      Y      |    Y     |  N   |   N   |    N     |
| [ICNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/icnet)[\*](#static_shape)          |      Y      |      Y      |    Y     |  N   |   N   |    Y     |
| [ISANet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/isanet)[\*](#static_shape)        |      N      |      Y      |    Y     |  N   |   N   |    Y     |
| [NonLocal Net](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/nonlocal_net)               |      ?      |      Y      |    Y     |  Y   |   N   |    Y     |
| [OCRNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/ocrnet)                           |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [PointRend](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/point_rend)[\*](#static_shape) |      Y      |      Y      |    Y     |  N   |   N   |    N     |
| [Semantic FPN](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/sem_fpn)                    |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [STDC](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/stdc)                               |      Y      |      Y      |    Y     |  Y   |   N   |    Y     |
| [UPerNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/upernet)[\*](#static_shape)      |      N      |      Y      |    Y     |  N   |   N   |    N     |
| [DANet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/danet)                             |      ?      |      Y      |    Y     |  N   |   N   |    Y     |
| [Segmenter](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/segmenter)[\*](#static_shape)  |      N      |      Y      |    Y     |  Y   |   N   |    Y     |
| [SegFormer](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/segformer)[\*](#static_shape)  |      Y      |      Y      |    Y     |  N   |   N   |    Y     |
| [SETR](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/setr)                               |      ?      |      Y      |    N     |  N   |   N   |    Y     |
| [CCNet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/ccnet)                             |      ?      |      N      |    N     |  N   |   N   |    N     |
| [PSANet](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/psanet)                           |      ?      |      N      |    N     |  N   |   N   |    N     |
| [DPT](https://github.com/open-mmlab/mmsegmentation/tree/main/configs/dpt)                                 |      ?      |      N      |    N     |  N   |   N   |    N     |

## Reminder

- Only `whole` inference mode is supported for all mmseg models.

- <i id="static_shape">PSPNet, Fast-SCNN</i> only support static shape, because [nn.AdaptiveAvgPool2d](https://github.com/open-mmlab/mmsegmentation/blob/0c87f7a0c9099844eff8e90fa3db5b0d0ca02fee/mmseg/models/decode_heads/psp_head.py#L38) is not supported by most inference backends.

- For models that only supports static shape, you should use the deployment config file of static shape such as `configs/mmseg/segmentation_tensorrt_static-1024x2048.py`.

- For users prefer deployed models generate probability feature map, put `codebase_config = dict(with_argmax=False)` in deploy configs.