Thermal cameras as a solution can reduce much of the noise caused by environmental conditions, especially outdoors, making it easier for video content analysis (VCA) algorithms to detect and track targets of interest while reducing nuisance alarms. “A common misconception with VCA is that detecting a target is difficult. When in fact, the more difficult task is typically not detecting something that is not of interest such as lighting changes, rain, snow, moving vegetation, reflections, shadows, etc.,” said Eric Olson, VP Marketing at Puretech Systems.
“A common misconception with VCA is that detecting a target is difficult. When in fact, the more difficult task is typically not detecting something that is not of interest such as lighting changes, rain, snow, moving vegetation, reflections, shadows, etc.”
- Eric Olson, VP Marketing, Puretech Systems
John Romanowich, President and CEO of SightLogix sees thermal cameras combined with video analytics as the optimal solution. “Thermal cameras are a perfect a human detector; they can see over the large distances typical of a perimeter application; and will ignore all the lighting problems that trigger false alerts for visible cameras. Now that there’s been a great drop in thermal image costs, along with a great increase in their performance, thermal cameras with video analytics have become the solution of choice for perimeter security.”
The introduction of high-resolution thermal cameras has had a big economic impact. Higher-resolution thermal cameras provide value by significantly lowering the costs to protect large perimeters. “The key for unlocking this value is the reduction of infrastructure: poles, power, and communication, which can easily be the most expensive part of an outdoor system. With an increased amount of pixels, higher-resolution thermal cameras increase the area they can reliably detect. This allows you to use fewer cameras to secure an outdoor perimeter,” explained Romanowich.
“By combing thermal detection cameras with automatically steered HD visible cameras, you gain complete situational awareness over the entire perimeter.”
- John Romanowich, President and CEO, SightLogix
“However, despite having come a long a way in providing a very good black and white image with visual details all day and night, (even in bright sun which in the past was difficult for thermal cameras), thermal cameras are not able to provide the same level of details to match an HD visible camera. This is why the best approach is to combine thermal for detection with visible for alarm assessment. Some thermal cameras are able to automatically steer and zoom an associated HD PTZ camera onto the detected target in real time, allowing security personnel to accurately and quickly classify the alarm. By combing thermal detection cameras with automatically steered HD visible cameras, you gain complete situational awareness over the entire perimeter,” Romanowich added.
Boghos Boghossian, CTO of UK-based Ipsotek points to some risks associated with thermal cameras: “Thermal cameras are great, but aren’t perfect. Thermal sensor range provides information that is in some cases difficult to interpret; the UK home office has done experiments which show it is possible to camouflage an intruder if they are covered by a thermally isolating/reflecting material that is in similar temperature to the surrounding. This gives the cover the temperature of the environment and can hide the existence of an intruder. Similarly in water, a swimmer wearing a wet suit and a face mask (glass) also reflects very little heat to the environment that can be detected by the thermal camera.”
“Perimeter scenarios, for example in border conditions, are very demanding and tricky. Any shake of the camera will cause a problem with the VCA. Therefore it is important to install appropriate stabilization solutions both mechanical and optical.”
- Boghos Boghossian, CTO, Ipsotek
Ipsotek tackles these issues through a technology it calls regional sensitivity. “Basically, we measure movement in different parts of the scene and we can focus with a higher resolution on places where we detect activity. Similar to what the human eye does. We can increase the accuracy level and pick up on slight coherent changes in the thermal signature since we see patterns of movement.”
Another problem Boghossian pointed to is camera shake in long-range image-based detection. “The higher the distance covered the more critical is proper installation. Perimeter scenarios, for example in border conditions, are very demanding and tricky. Any shake of the camera will cause a problem with the VCA. Therefore it is important to install appropriate stabilization solutions both mechanical and optical.”
However, security systems are only one side of the equation. On the other side stands the intruders who will do whatever they can to avoid detection. Intruders will take advantage of darkness and bad weather to infiltrate a perimeter. Thermal cameras can eliminate these factors to a large degree and combined with VCA, thermal cameras can increase detection rates and deliver highly accurate results.