Absolute zero: Object over absolute zero (-273.15°C) can emit infrared radiation.
A thermal camera detects and measures the infrared radiation emitted by the objects. After converting the infrared data into electronic signals, the program can form a thermal image of different grayscale or color to show the apparent surface temperature of the object being measured.
The images output from the thermal cameras are usually called "thermal images". The radiation ability varies with different objects or even different parts of the same object, and their reflection of infrared also varies.
Thermal cameras have various applications, such as industrial temperature measurement, outdoor night vision, ADAS, family health care, field rescue, outdoor observation, industrial temperature measurement, fire rescue, showing the difference between the observed object and the background in different grayscale or colors. Personal thermal camera generates images by receiving the infrared radiation emitted by the observed object, which is completely passive, without emitting any radiation to disturb the target.