Thermal cameras capture thermal energy emitted by the objects in the scene. This allows thermal motion tracking algorithm to distinguish between people, which have usually a higher temperature, from their background. This approach allows for tracking of people that are still for a longer period of time. However, if the temperature of the environment or of the surrounding objects is equal to that of the people, the tracking won’t be any more accurate than with video-based tracking. It might actually be even lower.
What to be mindful of
Thermal feed tracking is most commonly used when the goal is to track people (as opposed to cars for example). Especially in temperate climates, people are usually warmer than their surroundings. However, it is always necessary to be mindful of the temperature of the surrounding objects. For example, heating bodies or asphalt heated by the sun could significantly disrupt the tracking.
Thermal cameras are much more expensive than video cameras. In fact, they are most commonly used in completely different types of applications such as military or handheld surveying. It is important to choose the right model with sufficient protection against the elements.
This is an excerpt from our guidebook on Technologies for Interactive Architecture.