Color Mapping

Table of Contents

• Color maps and LUTs
• Applying LUTs to any image

Color maps and LUTs

A lookup table (LUT) is a data structure used to remap raw data values to a new range of data values. Often this is used to false color an image by remapping raw pixel values through a LUT to a new range of RGB color values. This process is also known as color mapping.

Volume Cartographer provides support for linearly remapping images to a number of built-in color maps using the volcart::ApplyLUT functions. The basic process is as follows:

#include <vc/core/util/ApplyLUT.hpp>
#include <vc/core/util/ColorMaps.hpp>
 
using namespace volcart;
 
// Get the LUT by enum or by string name
auto lut = GetColorMapLUT(ColorMap::Viridis);
lut = GetColorMapLUT("viridis");
 
// Automatically remap to the data min/max
auto mapped = ApplyLUT(image, lut);

Available color maps include:

Color map	Output range
Magma
Inferno
Plasma
Viridis
BWR

See volcart::ColorMap for a full list of available color maps.

Applying LUTs to any image

We provide the vc_color_map utility for remapping arbitrary images to one of our built-in color maps:

vc_color_map --input foo.png --output bar.png --color-map viridis

Run vc_color_map --help for more options and information.