Thermography is infrared photography with which temperature differences of object surfaces are displayed. Thermography works with infrared sensors that detect infrared radiation from body surfaces. This applies to all temperatures above the absolute zero point of 0 Kelvin
or -273 °C. This thermal radiation cannot be seen by the human eye. Thermography is about recording temperatures and temperature differences. Thermography is technically realized in thermal imaging cameras, which are equipped with infrared sensor arrays and convert the slightest temperature differences into electrical voltages. The resulting voltage image shows a monochromatic image with the temperature differences. Black areas of the image correspond to cold temperatures and bright or white areas to high temperatures. For better clarity, the different brightness areas are colored using image processing so that each temperature is assigned its own color
. From the resulting thermal image, the slightest differences in temperature can be detected by means of the color differences.