Brush, Pen, and Bucket

Overview of the Brush labeling tool in Ango Hub

The brush labeling tool allows you to "paint" on an image or video frame. The Brush tool also includes a bucket to paint areas of similar color, and a pen to create brush strokes by first drawing their outline.

Adding a Brush tool to your project

From the project’s Settings tab, enter the Category Schema section.

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

A new row will appear named Bounding Box. Click on it to expand it.

Give your brush tool a title and description.

Enable the Required toggle if you want to force labelers to create brush traces for each asset. When the toggle is disabled, labelers will be able to save and move to the next asset without creating brush traces using the class you've just created.

If you would like to ask labelers further questions, for example, if you want to show a further radio after drawing brush traces, click on Add Classification and add a further question. More on nested questions here.

Brush and Bucket Options

When the Brush Tool is enabled

When you select a Brush tool, a number of options will appear on screen, allowing you to pick a tool between brush and bucket, and more. Here is what will appear once you select a brush:

Erase: When the Brush tool is selected and the scissors are enabled, the brush will act as an eraser and erase existing traces.

Overwrite: Normally, the brush will not paint over existing traces. When this toggle is enabled, it will.

Size Slider: Change the size of the brush tool.

Pen Tool: switch to the Pen tool.

Bucket Tool: switch to the Bucket tool.

When the Brush tool is active, left click anywhere on the asset to create a brush trace.

When the Pen Tool is enabled

Brush Tool: Click here to switch to the Brush tool.

Erase: The pen will act as an eraser and erase existing traces.

Overwrite: Normally, the pen will not paint over existing traces. When this toggle is enabled, it will.

Bucket Tool: switch to the Bucket tool.

When the Pen tool is enabled, click and drag anywhere on the asset to draw an outline.

When the Bucket Tool is enabled

Brush Tool: Click here to switch to the Brush tool.

Pen Tool: switch to the Pen tool.

Current Color: Shows the color currently under the bucket tool.

Contiguous Toggle: When disabled, clicking on a color on the image will select all pixels of the same and similar colors on the image regardless of position. When active, it will limit itself to a contiguous area.

Threshold: pick a sensitivity for the bucket tool. When threshold is set to 100, for example, the area selected by the bucket will be larger, including more color shades.

Using the Brush Tool

Select a Brush tool from the Tools section in the left sidebar of the labeling editor. Click and drag on the image where you'd like to draw traces. Use the Scissors as necessary to erase traces.

Deselect the brush tool when you are done.

Using the Bucket Tool

Select a Brush tool from the Tools section, then toggle the Bucket tool.

Choose whether the bucket should behave contiguously or not, then click on a color. The color you're hovering over will be visualized on top of the tolerance slider.

Using the Pen Tool

Keyboard Shortcuts

ConditionKeyboard ShortcutAction

Brush is selected

Shift + Scroll

Change Brush Size

Bucket is selected

Shift + Scroll

Change Bucket Tolerance

Last updated