Image Calculator

This node evaluates a (free-form) mathematical expression based on the images in a row. The computed results can be either appended as new column or be used to replace an input column. Available variables are the values in the corresponding row of the table (left list in the dialog). Commonly used functions are shown in the list "Mathematical Functions".

This node uses JEP , the Java Math Expression Parser .

Options

Math Expression

Column List
Available image input columns. Click any column name to include the value in the expression text field.
Mathematical Function
Mathematical functions that can be used, the tooltip shows a short description for each function.
Constants
Constant values available during execution.
Expression
A mathematical expression. Constants, e.g. numbers (2*...) can be used as well, but at least one image column must be part of the expression.
Result pixel type
Specifies the pixel type of the result image (and the pixel types of the intermediate result images). If this pixel type cannot hold the computation results, behavior is undefined.

Advanced Settings

Reference Image
Result images get dimensionality definitions and metadata from the reference image. If none is selected the reference column will be set to the first column in the incoming table that is used in the computed expression.
Adjust Dimensions
Activate to allow calculations on images with different dimensionalities. The result dimension will be taken from the reference image.

Input Ports

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Images

Output Ports

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Result images

Popular Predecessors

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Popular Successors

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Views

Table Cell View
More detailed view on the result images.

Workflows

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Links

Developers

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Installation

To use this node in KNIME, install the extension KNIME Image Processing from the below update site following our NodePit Product and Node Installation Guide:

v5.9
Plugin provider: University of Konstanz
Plugin version: 1.8.3.v202512031239
On NodePit since: 2025-12-12
Last update: 2026-01-11
Tags: Streamable
KNIME versions: Since v5.2

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