The spectrum of visible light is actually only a small part of a large band of detectable signals, or waves, that travel through matter. The electromagnetic spectrum contains radiation from various invisible wave types, each with a unique wavelength. Thermal radiation is one of these, featuring longer wavelengths than those of visible light, and is therefore generally invisible to the human eye.
Any object with a temperature above absolute zero emits a detectable amount of radiations. The higher an object’s temperature, the more radiations are is emitted. Taking advantage of the temperature differences between objects, thermal cameras make the invisible thermal radiation “visible” in the form of heat zone images.
The image reproduction of thermal cameras is not affected by lighting conditions - either extremely low light or even no light at all. And compared with imaging with visible light, thermal cameras are much less impacted by weather conditions such as fog, smog, rain and snow, so that they can work in virtually any environment, anytime.
Video Content Analysis
Thermal imaging has an intrinsic advantage for video content analysis (VCA) – it renders objects with clear outlines that stand out pretty well against the background, even at great distances. Users can easily set up VCA rules to detect actions such as line crossing, intrusion, region entrance, and region exit with high accuracy.
Rapid technological changes in thermal imaging recently has led to a decline in the cost of thermal products along with a rapid expansion in their applications across industries. Thermal imaging has gone from niche to public markets in a relatively short period.
Thermal imaging is rapidly expanding from its conventional applications in military, law enforcement and temperature measurement to new domains such as forest fire prevention, crop burning monitoring, indoor fire prevention, perimeter defense, border defense, coast defense, and intelligent transportation. Full use of its environmental adaptability and long-range detection capabilities is coming into focus.
This booming market is benefiting from a full range of technological innovations – such as detectors, lenses, and SoCs – along with innovations in the manufacturing processes. Now, miniaturized, intelligent thermal products are rolling out for industrial temperature measurement, handheld temperature measurement, driving assistance, medical services, or as peripherals of drones and smart phones. Some industries even see disruptive innovations in the application of thermal technology. The diversification of applications will continue to expand the market for thermal imaging and accelerate continuous growth in this specialized industry.
The popularization of AI technology in recent years has also promoted technological advances in thermal imaging, as more and more deep-learning-based thermal applications become a part of people’s everyday life.
Creating deep-learning algorithms for behavior analysis, smoke and fire detection, and vessel identification, Hikvision is pioneering the fusion of thermal imaging and AI technologies to significantly improve alarm accuracy in areas such as forest fire prevention and perimeter defense. We believe that front-end intelligent diagnosis, traffic event detection and other thermal-based technologies will be applied in fields like industrial temperature measurement, human body temperature measurement, handheld temperature measurement, intelligent transportation, driving assistance, and drones.
Fused Technologies and Smart Linkage
When it comes to rendering images of a given resolution, infrared detectors are much more costly than the CMOS or CCD sensors. The lower pixel count transmitted from infrared detectors usually means reduced image detail. However, Hikvision’s signature thermal technology – bi-spectrum image fusion – combines features from both thermal and optical images to create a unique hybrid image that provides extra details for users in the pursuit of high resolutions and smart applications.
Adding to image fusion within a bi-spectrum thermal camera, the smart linkage of thermal cameras with IP cameras puts the advantages of both into one system. Thermal cameras provide high-precision video analytics that are unhindered by weather conditions, and IP cameras offer HD video footage and facial recognition functions to facilitate event investigation.