Dynamic ROI

Overview

The Dynamic ROI node filters input polygons by checking if they fall within a region of interest (ROI) that is supplied as an input at runtime. Unlike the static Region of Interest node, where the ROI is configured once.

Use Dynamic ROI when:

• The region of interest moves or changes shape at runtime (e.g. a tracked object defines the boundary).
• You want to separate detected objects into those within a specific zone and those outside it, and the zone is not fixed.

💡 Tip

For a fixed region that does not change, use the Region of Interest node instead. It provides a visual editor for drawing the ROI directly on a reference image.

Inputs

Name	Type	Description
polygons	list[polygon]	The list of detected polygons to be classified.
roi	polygon	The polygon defining the region of interest, supplied at runtime in the flow.

Outputs

Name	Type	Description
inside	list[polygon]	Polygons that are within the ROI.
outside	list[polygon]	Polygons that are outside the ROI.

Parameters

Parameter	Default	Valid values	Tunable
Check method	center	center	❌

Check method

The rule used to determine if a polygon is "inside" the ROI. The node checks if the geometric center of each input polygon falls within the ROI boundary. Currently center is the only supported method.

Example

Filtering detections inside a tracked zone

A camera monitors a workshop floor. A separate detection model outputs a polygon representing a restricted area that shifts as equipment is moved. The Dynamic ROI node receives that polygon as its roi input and classifies detected people into those inside the restricted zone and those outside it.

Configuration:

• Check method: center

Result: People whose polygon falls within the restricted-area are sent to the inside output for alert processing. All others appear on the outside output.

Related links

Reference:

• Region of Interest — static region of interest filtering
• Polygon Threshold — filtering polygons based on size or classification