Vector to Scalar Volume


This module is useful for converting RGB (vector) volumes to one component (scalar) grayscale volumes.

Vector volumes are typically loaded from a series of jpg, png, bmp, or other classic 2D image formats.

While vector volumes can be visualized in the slice viewers, many slicer operations only operate on scalar volumes (such as segmentation and registration modules).

Panels and their use

  • Parameters:

    • Input vector volume

    • Conversion Method:

      • Luminance: convert RGB images to scalar using luminance as implemented in vtkImageLuminance (scalar = 0.30R + 0.59G + 0.11*B).

      • Average: computes the mean of all the components.

      • Single Component Extraction: extract single components from any vector image.

    • Output scalar volume

Volume of JPG files from the visible human project converted to a scalar volume using the Luminance method.


  • Steve Pieper (Isomics)

  • Pablo Hernandez-Cerdan (Kitware)

  • Jean-Christophe Fillion-Robin (Kitware)

  • Andras Lasso (PerkLab)


This work is part of the National Alliance for Medical Image Computing (NA-MIC), funded by the National Institutes of Health through the NIH Roadmap for Medical Research, Grant U54 EB005149. Information on NA-MIC can be obtained from the NA-MIC website.