Documentation Substance 3D Substance 3D Designer

Histogram compute

Last update: May 6, 2026

Histogram compute: icon {width="200px"}

In: Filters > Adjustments

Description

Computes the histogram for a grayscale image.

The histogram is encoded as a row of pixels in an image, where each pixel value is the population of the color value matching the pixel position on the X-axis.
E.g., a pixel value of 75 at (0.25, 0) means there are 75 pixels which have the 0.25 color value in the image.

The node also outputs the cumulative distribution function (CDF) computed for the image.

Custom tools can be created using the data computed by the node, such as custom masks, as shown below in the ‘Examples’ section.

IMPORTANT

All values out of the [0,1] range are clamped, therefore the histogram may not be accurate for HDR images.

Output connectors

Parameters

Input connectors

Input Grayscale PRIMARY

The image for which the histogram should be computed.

Output connectors

Histogram Grayscale

The histogram computed for the input image, encoded as a row of pixels where each pixel value is the population of the color value matching the pixel position on the X-axis. E.g., a pixel value of 75 at (0.25, 0) means there are 75 pixels which have the 0.25 color value in the image.

CDF Grayscale

The result of the cumulative distribution function (CDF) computed for the image, encoded in a row of pixels where each pixel is the sum of all pixel values to its left. That sum is then normalized against the total number of pixels in the image.