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Module category: Filter


This module is able to calculate distances between color data.


The module owns three ports for incoming and one port for outgoing data. The input ports accept RGB data, while the output port delivers the alpha channel.



The calculation of the color distance can be modified by a few parameters:

This is the color value on which the calculation is based on. You can choose the color from a color table (folder button), a color picker (pipet button) or you can fill in manually the RGBA values.
Two different metrics can be used to calculate the color distance. You can choose between:
DistanceBase, DistanceMultiplier
The sliders represent values for the calculation of the distance. This way, the calculation can be modified directly out of the Map Editor.


Name Type Description
ReferenceColor Color Color to which the distance is calculated
Metric Choice Metric for calculation of the distance for transparent values.
DistanceBase FloatSlider This value is added to the calculated distance.
DistanceMultiplier FloatSlider This value multiplies the calculated distance.

Input Ports

Name Type(s) Description
Red Float Scalar volume data (red channel)
Green Float Scalar volume data (green channel)
Blue Float Scalar volume data (blue channel)

Output Ports

Name Type(s) Description
Data Float Scalar volume data


A "classical" combination for this module is the example ColorDistance.net. It uses the module ColorDistance for adding an alpha channel to the RGB data to handle the opacity.


Authors: Martin Aumüller, Ruth Lang, Daniela Rainer, Jürgen Schulze-Döbold, Andreas Werner, Peter Wolf, Uwe Wössner
Copyright © 1993-2016 HLRS, 2004-2014 RRZK, 2005-2014 Visenso
COVISE Version 2016.3