# Segmentation Assistant for ROItool (nnInteractive)
[](https://nora-imaging.org/doc/uploads/images/gallery/2025-11/wlHimage.png)
This assistant allows users to create and refine 3D ROIs using interactions. Images, masks, and successive interactions are processed by a deep learning model hosted on a remote server.
The current version of the model is **nnInteractive** (Isensee, Rokuss, Krämer et. al., 2025). [nnInteractive repository](https://github.com/MIC-DKFZ/nnInteractive)
## 1. Usage
First, **select an ROI** from the ROI list to make it the active target for segmentation.
### Point Interaction
- Click the **Point** icon (crosshairs) to activate Point mode
- **Left-click** on the image to add a **positive** point (to include an area)
- **Right-click** on the image to add a **negative** point (to exclude an area)
- The segmentation will be updated immediately. Click the icon again to deactivate
- To add multiple points before updating the segmentation, **hold down the Q key** while adding points. Release the Q key to send all accumulated points at once
### Scribble Interaction
- Click the **Scribble** icon to activate Scribble mode and draw a scribble on the image
- Click the **+** button to run a **positive** interaction (add areas)
- Click the **-** button to run a **negative** interaction (remove areas)
- Scribbles are cleared after each interaction, allowing you to add more
### BBox Interaction
- Click the **BBox** icon (square) to activate Bounding Box mode and draw a box on the image
- Click the **+** button for a **positive** interaction (segment inside the box)
- Click the **-** button for a **negative** interaction (exclude area in the box)
- The box is cleared after each interaction
### Reset Interactions
- When editing the same ROI, all previous interactions are kept in memory server-side to guide the segmentation
- Click the **Reset** icon (eraser) to erase all previous interactions and start fresh
## 2. Server Setup
The segmentation server must be running, typically on a machine with a GPU. First, navigate to the `src/python/segmentation_assistant_server` directory and launch the `setup.sh` script (requires internet access):
```bash
cd src/python/segmentation_assistant_server
./setup.sh
```
This will create a Python virtual environment and install the necessary dependencies.
Next, start the server from a computing node with:
```bash
cd src/python/segmentation_assistant_server
./start.sh
```
## 3. Client Configuration
Once the server is running, it will log its port. You must update this client's configuration to point to that address.
Edit the file: `conf/segmentationserver.conf`
Set the `REMOTE_SEGMENTATION_BASE_URL` to the server's address, for example:
```json
{"REMOTE_SEGMENTATION_BASE_URL":"http://:PORT"}
```
**Important:** You must restart Nora for the changes to take effect.