Heatmap Threshold

Overview

The Heatmap Threshold node filters a heatmap by setting the pixels to 0 if their values are below the threshold. By default it binarizes the result — pixels at or above the threshold become 255 (white) and everything below becomes 0 (black). Disable binarization to keep the original intensity values instead.

Use Heatmap Threshold when:

• You need to suppress low-intensity noise and keep only the strongest values.
• You want to create a thresholded heatmap for downstream processing while retaining intensity information.

💡 Tip

Adjust the threshold carefully to balance between capturing relevant details and excluding background noise. Try disabling binarization when you need to preserve intensity differences above the threshold.

Inputs

Name	Type	Description
heatmap	image	Receives the input heatmap.

Outputs

Name	Type	Description
thresholded	image	The thresholded heatmap. Pixels below the threshold are 0. Pixels at or above are set to 255 when binarization is enabled, or keep their original value when it is disabled.

Parameters

Parameter	Default	Valid values	Unit	Tunable
Heatmap threshold	0	0 – 255	8-bit levels (0–255)	✅
Binarize heatmap	true	true / false	-	✅

Heatmap threshold

The pixel intensity cutoff (0–255). Pixels with values equal to or above the threshold pass through; pixels below are set to 0. This value can be changed at runtime.

Binarize heatmap

Controls what happens to pixels that pass the threshold.

• true (default): All pixels at or above the threshold are set to 255 (white), producing a binary mask.
• false: Pixels at or above the threshold keep their original intensity value.

Example

Isolate Hotspots

A heatmap represents temperature across a surface. You want to isolate areas exceeding a specific intensity with threshold = 150.

Input — grayscale heatmap with hotspots of varying intensity.

Binarized (default) — pixels ≥ 150 become white, all others are black.

Value-preserving — pixels ≥ 150 keep their original intensity, all others are black.

Related links

Reference:

• Polygon Threshold — filters polygons based on spatial criteria
• Overlay Heatmap — overlays a heatmap onto an original image
• Apply Mask — uses a binary mask to isolate areas of an image