# Polygon

The polygon labeling tool allows you to draw a polygon around an object or point of interest in an image.

{% hint style="info" %}
The Polygon tool is supported across the Image, Video, and DICOM labeling editors.
{% endhint %}

![](https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Mj9Q2CMggO8ujraHZeP%2F-Mk6PkSagTqxzKOwanFv%2F-Mk6RM2QuvmcpdFGrTI2%2Fimage.png?alt=media\&token=ebd9e7f9-ed24-4fd7-9101-d44fe26a5f2c)

## How to add a Polygon tool to your project <a href="#how-to-add-a-polygon-tool-to-your-project" id="how-to-add-a-polygon-tool-to-your-project"></a>

From the project’s *Settings* tab, enter the *Label Set* section.

Click on *Add Category*. From the list that appears, click on *Polygon*.

A new row will appear named *Polygon*. Click on it to expand it.

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FkCmnVBQij1T6zlIIgyyt%2Fimage.png?alt=media&#x26;token=b3769293-dd0a-44cd-8c38-9d0bec4b8f64" alt=""><figcaption></figcaption></figure>

Give your polygon tool a title and description.

Enable the **Required** toggle if you want to force labelers to create a polygon on every asset. When the toggle is disabled, labelers will be able to save and move to the next asset without creating a polygon.

If you would like for your polygon to appear curved, enable the **Curved** toggle. Please note that this is a purely visual change and does not affect the final export in any way.

If you would like to ask labelers further questions, for example, if you want to show a further *radio* after drawing the polygon, click on *Add Classification* and add a further question. More[ on nested questions here](https://docs.imerit.net/labeling/labeling-tools/tools/nested-classifications).

## How to Draw a Polygon <a href="#how-to-draw-a-polygon" id="how-to-draw-a-polygon"></a>

Click on the image where you’d like the first point of the polygon to be. Click again where you’d like the second point to be, and so on. When you are done, click on the first point again or press on *N* on your keyboard to close the polygon.

![](https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-Mj9Q2CMggO8ujraHZeP%2F-Mk6PkSagTqxzKOwanFv%2F-Mk6RkCD23lR2oJ6olsG%2Fimage.png?alt=media\&token=8b0c867d-0b20-4800-b815-4534056e6b66)

While drawing, you may click anywhere with the right mouse button to delete the last point you have placed.

To add a new point after closing the polygon, hold CTRL and click anywhere on an edge to add a point. To delete a point, hold CTRL and right-click on the point you’d like to delete:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2F7rWZohKmFQNTn9ksXdKQ%2Fdelete-poly.gif?alt=media&#x26;token=9b3fa761-af13-46d5-9881-51a5a06bffc7" alt="" width="255"><figcaption></figcaption></figure>

To quickly trace a polygon without having to click on each point manually, after having drawn the first point, hold *Shift* then start moving your cursor:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FHkGpgd8DXLIbvbkBu9Yp%2Fpolygon-continuous.gif?alt=media&#x26;token=a0d6c467-e567-44d1-acca-746dae18dbc8" alt=""><figcaption></figcaption></figure>

## Edge Sharing

While drawing a polygon, if you press E, Hub will highlight the points of other polygons, polylines, and points. By clicking on the other object's points, you can snap your current polygon's points to them:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FUkCaCfDEJG79xPYa454M%2Fedge-sharing.gif?alt=media&#x26;token=00130e62-c27f-4337-9b76-11e972bdea75" alt=""><figcaption></figcaption></figure>

You can also share edges with the polygon itself the same way:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FSZjYQefzK6JILB0v7MfE%2Fsame-poly.gif?alt=media&#x26;token=220addab-25c5-4a8f-9276-c27e133790c5" alt=""><figcaption></figcaption></figure>

By snapping at least two points to the existing polygon and holding Alt (⌥ on macOS) + clicking, you can quickly anchor a series of points to the existing object:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FtaGwMbLuXKZDnNzCiwrS%2Falt.gif?alt=media&#x26;token=4f8f6ff0-a841-4432-b01e-51ccc9b1a9b5" alt=""><figcaption></figcaption></figure>

## Nudge Tool

You can apply small changes to your polygons by 'nudging' them.

To nudge a polygon, click on the polygon on the asset, then pick the type of nudge tool you'd like to use:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FpPtNXM38R2taD7JASVBn%2Fimage.png?alt=media&#x26;token=37614f9a-7379-448c-8474-790817bd751d" alt=""><figcaption></figcaption></figure>

Nudge Erase will allow you to reduce the size of your polygon while applying small changes. Nudge Draw will add area to your polygon.

Once you have picked your nudging tool of choice by clicking on either the "plus" or the "minus", click and drag around the polygon's edge to refine the edge of your polygon:

<figure><img src="https://3895963154-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTcOUG6rfWxqGM0N4db2P%2Fuploads%2FMigrJNC8X9FHNI77rhtV%2Fnudge-tool-complete.gif?alt=media&#x26;token=0d47299e-ee67-4737-a62d-9817bd58eebc" alt=""><figcaption></figcaption></figure>
