Annotate Polygons

Overview

Assigns visual attributes to a list of polygons — color, line thickness, opacity, and labels. Use this node to define how detections from an AI model or any other polygons should appear when rendered by the Draw Polygons node.

Use Annotate Polygons when:

• You want to color-code different object classes (e.g., green for "pass", red for "fail").
• You need to add text labels to detected objects for visual inspection.
• You have multiple detection categories that each need distinct styling — add one Annotate Polygons node per category.

💡 Tip

This node only defines visual attributes; it does not draw polygons on the image. Connect its output to a Draw Polygons node to render the results.

Inputs

Name	Type	Description
polygon_list	list[polygon]	The list of polygons to receive the visual attributes.
label	string	An optional text label applied to every polygon in the list.

Outputs

Name	Type	Description
annotated_polygon_list	list[polygon]	The polygons with the assigned color, thickness, and label properties.

Parameters

Parameter	Default	Valid values	Unit	Tunable
Polygon Color	#00FF00	hex string	-	✅
Label Color	#FFFFFF	hex string	-	✅
Label Font Size	14	8 – 48	px	✅
Label Position	top_left	top_left, bottom_left	-	✅
Line Thickness	2	1 – 5	px	✅
Opacity	0	0 – 100	%	✅

Polygon Color

The hex color code for the polygon outlines. Click the color preview to open a dialog with HEX and RGB inputs, or select a color visually from the gradient palette.

Hex color picker for setting polygon outline color and label color.

Label Color

The hex color code for the label text. Uses the same color picker as the Polygon Color field.

Label Font Size

The size of the text used for polygon labels, in pixels.

Label Position

Determines where the text label is anchored relative to the polygon:

• top_left (default) — top-left corner of the polygon bounding box.
• bottom_left — bottom-left corner of the polygon bounding box.

If a label would extend beyond the image boundary, the position switches automatically to keep it visible. The label background uses the polygon's color for easy visual association.

ℹ️ Label Positioning

Labels are automatically repositioned to avoid overflow outside the image. If a label would extend beyond the top, bottom, or right edge of the image, it switches to the opposite vertical position or shifts horizontally to stay visible.

Line Thickness

The width of the polygon borders in pixels.

Opacity

The fill transparency of the polygons. 0% is fully transparent, 100% is fully opaque.

Example

Defect inspection with two categories

A model identifies products as either acceptable or defective. Use two Annotate Polygons nodes: one colors acceptable items green with a "Pass" label, the other colors defective items red with a "Defect" label.

Configuration (defect node):

• Polygon Color: #FF0000
• Label Font Size: 18

Result: Defective polygons appear with a red border and an 18 px "Defect" label. Acceptable polygons appear green with "Pass".

Two detections annotated with red polygon outlines and a 'Defect' label showing the confidence percentage. The label background matches the polygon color for quick visual association.

Related links

Reference:

• Draw Polygons — renders the annotated polygons onto an image
• Polygon Blur — applies Gaussian blur to polygon regions