Not to be confused with an optical camera which captures images based on light reflecting from objects, a thermal network camera generates a picture based on the heat that an object radiates.
This has made thermal devices an ideal solution for surveillance at night, where optical cameras are limited in their use due to a lack of light. Historically, however, thermal cameras have a reputation for being a costly investment, especially for a technology that many believe can only used in the hours of darkness.
But thermal imaging technology has evolved. The new generation of cameras is even more sensitive; and images are processed with sharpness and noise-elimination filters, so detailed images can be obtained from cost-effective 640×480 sensors, both at night and during the day. This combination of increased cost-effectiveness and suitability for round-the-clock surveillance means thermal network cameras are becoming more commonly deployed as part of modern-day integrated security systems.
Such technology is being utilised from company car parks to commercial airfields, acting as a first line of defense for detection, visual verification and analysis of scenes. While a new breed of thermal cameras, such as the AXIS Q87 bispectral series, are combining pictures from networked thermal cameras with high definition optical cameras within one shell, there are now more budget friendly alternatives to help all businesses benefits from thermal cameras.
This includes the AXIS P1290 Thermal Network Camera, which delivers all of the benefits of thermal detection at a cost-effective price. This is giving more security operators the ability to receive a complete picture of what’s happening in front of them 24 hours a day, seven days a week.
Why thermal imaging cameras matter
There are many scenarios which can trip up an optical-only system. For example, on a bright day, even wide dynamic range images might not be able to capture detail obscured by dark shadows, such as one cast by a large wall. Poor weather conditions can also make it difficult to capture clear images in rain, fog or mist.
Likewise, in busy environments such as a car park with lots of moving and stationary objects, it can be difficult to see exactly what’s happening in between solid parts of the scenery which hide movement. Is the movement behind parked vehicles a bag blowing in the wind or a potential criminal looking for an open door?
In both scenarios, there’s the danger that a CCTV operator will either miss an important incident or trigger a false alarm for investigation.
The same is true even for video surveillance systems where incidents are detected automatically using advanced video analytics – an intelligent network of cameras is only as smart as the data it is able to process, and sometimes even the best optical cameras can’t be sure of what they are seeing, plus, event the best video analytics remain susceptible to false alarms.
Thermal cameras, linked with effective video analytics, can provide another layer of protection, detection accuracy and false alarm reduction.
Enhancing a visual-only image with the addition of a thermal network camera, even on a clear day, can provide more certainty to what a camera is seeing. The difference between a bag and a car thief may not be much in the corner of a colour picture, but to a thermal camera the difference is stark. Similarly, there are no shadows to hide in when body heat will compromise the individual.
Increasing operational effectiveness with thermal detection
For further removal of doubt, thermal cameras can also operate like a traditional passive infrared sensor using Video Motion Detection (VMD). If a warm object is seen moving, a camera programmed for VMD can trigger security lighting to turn on – for example – providing a control room with more information about a scene before sending someone out to investigate. Thermal cameras deliver higher contrast video, so are inherently better at utilising video analytics capabilities built into them than would optical cameras be.
Thermal cameras, then, can quickly pay for themselves just in terms of reducing the costs of false alarms and adding an extra layer of protection for day and night surveillance. What’s more, they are simple to deploy and integrate into existing IP CCTV networks.Read more about intelligent systems and video analytics