APTP Articles

Picking a Thermal Colour Palette

While thermal images may sometimes look like standard photographs, their vivid colours or contrasting grayscale details represent a very specific, very large data set of temperature information. Understanding what these colours and shades represent can help with detecting everything from a water leak to a missing person.

Like any digital image, thermal images are made up of pixels. In thermal imaging, each individual pixel represents a specific temperature data point. These data points are assigned a unique colour or shade based on their value, meaning that as the thermal sensor detects changes in heat energy, it will express this change by adjusting the colour or shade of a pixel. 

Switching palettes changes the appearance of a scene and highlights key areas of a thermal image without altering any temperature data. Thermal palettes are largely a matter of user-preference, but different environments or situations might benefit from one palette over another. 

Here are the palette options you’re likely to see: 

IRONBOW:

A favorite among thermographers, Ironbow is a general-purpose palette that quickly identifies thermal anomalies using colour to show heat distribution and subtle details. Hot objects are shown in lighter, warm colours while colder objects are dark, cool colours.

Teledyne FLIR