Thermal cameras can be used for rapid and safe initial temperature screening of staff, visitors and customers. Used the right way, the cameras can help prevent unnecessary spread of viruses like the novel coronavirus. During the global pandemic, use of thermal cameras has increased, but they have not always been used correctly, and therefore, not effectively.

Hikvision’s temperature screening thermal products are currently assisting users in initial temperature screening across the global market. During 2020, demand increased in most markets, and the company highly recommends that Hikvision’s thermographic cameras be used in accordance with local laws and regulations. Limitations of the technology include throughput and the impact of ambient conditions.

Detect viruses and fever

Hikvision releases a video that illustrates how skin temperature measurements are normalised within minutes

Thermal cameras cannot detect viruses and fever and should only be used as a first line of screening before using secondary measures to confirm, says Stefan Li, Thermal Product Director at Hikvision. “We also believe it is important for businesses and authorities to use [thermal cameras] alongside a full programme of additional health and safety procedures, which includes handwashing, regular disinfection of surfaces, wearing protective clothing such as masks, and social distancing.”

Hikvision has released a video that illustrates how skin temperature measurements are normalised within minutes after someone emerges from the cold. Mr. Li says the video demonstrates the accuracy of forehead measurement under difficult circumstances when people come inside from a cold outdoor environment.

Temperature screening facilities

“There have been some claims that measuring the forehead temperature is not as accurate as measuring the inner canthus, and we believe this video demonstrates the accuracy of forehead measurement very well,” he says. “We also illustrate how the skin temperature will experience a process of recovery (warming up), no matter if it is measured by a thermal camera or a thermometer.”

Mr. Li adds that people should wait five minutes in such circumstances before starting a temperature measurement. “We hope that stakeholders who are involved in the design of temperature screening facilities and associated health and safety procedures will recognise how important it is to consider the skin temperature recovery time, and that forehead measurement can provide accurate test results,” says Mr. Li.

Thermal imaging manufacturers

The algorithm is based on a large number of test results to obtain a value that tends to be dynamically balanced

The temperature measurement principle of thermal imaging is to detect the heat radiation emitted by the human body. The detected heat value often does not reflect the true internal body temperature of an individual. Furthermore, the temperature varies among different parts of the human, such as the forehead, ears, underarms, etc. A temperature compensation algorithm can be used to adjust the measured skin temperature to align with the internal body temperature.

The algorithm is based on a large number of test results to obtain a value that tends to be dynamically balanced. At present, thermal imaging manufacturers in the market, and even forehead thermometer manufacturers, have developed their own algorithms to map the skin temperature measured by the camera to the internal body temperature, so as to compensate the skin temperature to the internal body temperature.

Thermal cameras

This is also why Hikvision recommends that the "actual body temperature" should be checked with a secondary device for confirmation. The calibration work for a thermal camera is completed in the production process at the factory, including calibration of reference values and detection point and so on. At the same time, the equipment parameters should be adjusted before on-site use to ensure accurate temperature reads.

Hikvision does not deny the accuracy of temperature measurement at the inner canthus but prefers forehead temperature measurement and algorithms based on actual use scenarios, says Mr. Li. A large amount of test data and practical results indicates that the forehead is a correct and easy-to-use temperature measurement area, says the company. There are advantages and disadvantages of choosing different facial areas for temperature measurement.

Default compensation temperature

Two main approaches direct the measurement area and how compensation algorithms are applied:

  • Forehead area + default forehead compensation algorithm value
  • Upper half face (forehead + canthus) + default inner canthus compensation algorithm value.

Both methods deploy compensation algorithms, but the default compensation temperature of the inner canthus will be less than the default compensation temperature of the forehead, generally speaking. The reason is that the temperature of the inner canthus of most people is higher than their forehead, so the temperature compensation is relatively low (i.e., closer to the actual temperature inside the body.)

Upper face area

Hikvision found that selecting the upper face area plus the default compensation value for the inner canthus resulted in situations when the calculated temperature is lower than the actual temperature.

For the Hikvision solution, the forehead is a relatively obvious and easy-to-capture area on an entire face

Mr. Li explains: “The reason is that when the camera cannot capture the position of the inner canthus (for example, when a person is walking, or the face is not facing the camera), the camera will automatically capture the temperature of the forehead. Then the result that appears is the sum of the forehead temperature plus the default compensation temperature of the inner canthus, which is lower than the actual temperature of the person being measured. Therefore, errors are prone to occur.”

Thermal imaging products

But for the Hikvision solution, the forehead is a relatively obvious and easy-to-capture area on an entire face. Also, the default forehead compensation temperature is based on rigorous testing and can also correctly mimic the actual temperature of the person being measured, says Mr. Li.

After many test comparisons, considering that the results of forehead temperature measurement are relatively more stable, and in order to avoid the false results from inner canthus temperature measurement, Hikvision chose the forehead temperature measurement approach. “We look forward to bringing thermal imaging products from a niche market where there is a relatively high-end industry application to a mass market and serving more users,” says Mr. Li.

Facial recognition terminals

Additional application parameters can maximise effectiveness of thermal cameras for measuring body temperature:

  • Positioning and height - All cameras must be mounted appropriately to avoid loss of accuracy and performance. The installation height of each camera must be adjusted according to camera resolution and focal length, and stable installation is needed to avoid errors caused by shaking.
  • Ensuring a ‘one-direction path’ - The detection area must ensure that cameras capture the full faces of all those passing by or stopping, and obstacles should be avoided in the field of view, such as glass doors that block the camera.
  • Adequate start-up and usage - A waiting time of more than 90 minutes is required for preheating, after the initial start-up. Before conducting a thermal scan, people should be given three to five minutes to allow their body temperature to stabilise. When Hikvision MinMoe facial recognition terminals are used, people must stand at a fixed distance, pass one by one, make a short stop, and face the camera directly. Hikvision cameras support efficient group screening, but one-by-one screening is suggested for more accurate results, says Mr. Li.

Unstable environmental condition

An unstable environmental condition may affect the accuracy of thermal camera systems

Environmental factors can impact the accuracy of thermal cameras, and the idea of using a black body is to provide the camera with a reference point that has a stable temperature. The black body is heated to a specific temperature and helps the thermal camera to know how much error is caused by environmental factors in the room, and how the camera should calibrate itself in real time to improve its accuracy.

A black body can help increase the temperature measurement accuracy, and the most common improvement is from ±0.5 degrees to ±0.3 degrees. However, it also increases the cost of the installation. In some markets, customers may require black bodies in order to comply with regulatory accuracy requirements. An unstable environmental condition may affect the accuracy of thermal camera systems for measuring temperature.

Medical temperature measurement

Therefore, Hikvision suggests that the ambient conditions should be met for installation and use. First of all, users should avoid installing devices in hot or changeable environments. All cameras require indoor environments with calm air, consistent temperature and no direct sunlight. Installation should also be avoided in semi-open locations that may be prone to changes in ambient conditions, such as doorways, and there should be enough stable, visible light.

All devices should be installed to avoid backlighting, high temperature targets, and reflections in the field of view as far as possible. “We often see the misconception that thermal cameras can replace medical temperature measurement equipment, which is not the case,” says Mr. Li.

Rapid preliminary screening

“Temperature screening thermographic cameras are designed for the detection of skin-surface temperatures, and the measurement should be conducted to achieve rapid preliminary screening in public areas. It is really important that actual core body temperatures are measured subsequently with clinical measurement devices.”

Share with LinkedIn Share with Twitter Share with Facebook Share with Facebook
Download PDF version Download PDF version

Author profile

Larry Anderson Editor, SecurityInformed.com & SourceSecurity.com

An experienced journalist and long-time presence in the US security industry, Larry is SourceSecurity.com's eyes and ears in the fast-changing security marketplace, attending industry and corporate events, interviewing security leaders and contributing original editorial content to the site. He leads SourceSecurity.com's team of dedicated editorial and content professionals, guiding the "editorial roadmap" to ensure the site provides the most relevant content for security professionals.

In case you missed it

Securing empty premises: Product performance is everything
Securing empty premises: Product performance is everything

Since the start of the pandemic, almost a quarter of UK businesses have been forced to temporarily close, pause trading, or work remotely, with very little notice. Now nearing the 12th month of the crisis, the country is currently enduring its third national lockdown, with an unspecified timeframe. Most workers are being urged to remain at home and only venture out for essential travel. This means a huge number of premises across the board, from recreational venues such as theatres, pubs and leisure centres, to office buildings, and storage facilities, will remain empty. It’s likely that security has been scaled back, so many buildings could be vulnerable to attack for the foreseeable future. Just recently we’ve seen empty pubs in London targeted by opportunistic illegal rave organisers. Physical security strategy Even rural areas aren’t exempt from the problem, as burglars have reportedly targeted beauty salons, etc Even rural areas aren’t exempt from the problem, as burglars have reportedly targeted beauty salons, food stores and vehicle hire premises this winter. Vandalism and burglary remain very real threats, therefore it is vital that facilities managers and property owners ensure the physical security of these empty buildings is maintained to the highest standard to protect property and the assets within. Below we outline key considerations when evaluating a physical security strategy for an empty building. Assess the risk We would urge facilities managers and building owners to carry out regular, thorough checks of the building and the perimeter to assess any obvious factors which would elevate the risk of attack. This includes assessing the location. Is the crime rate high? How visible is the property? Are the contents of the property on show? How secure is the access or perimeter boundary? View the premises from a potential intruder’s perspective, and when you can’t be at the site in person, use photographs, notes and drawings to identify potential weaknesses. For example, there may be high security fencing at the front of the premises, but make sure it is not at risk of being compromised at the back. Conducting regular maintenance Retain and maintain quality Inspecting the fence line may seem obvious and straightforward, but it needs to be a deliberate, scheduled event Conducting regular maintenance is even more essential while premises are left empty, as it is much easier for any issues to appear and escalate undetected. We highly recommend regularly inspecting your fencing for disrepair or damage as this can affect the perimeter’s integrity. Alternatively, choosing high quality galvanised and preferably powder coated steel fencing with a 25-year guarantee will offer longer-lasting protection against rust and corrosion. Inspecting the fence line may seem obvious and straightforward, but it needs to be a deliberate, scheduled event. Take time to check the perimeter on both sides. As you inspect the fencing, keep an eye out for any attempted breaches and note if foliage, weather conditions, or topography changes have affected security integrity. Check all fixtures and fittings are in good working order, look for damage and corrosion, and clear all litter and debris away. Huge security risk Quality investments In a time when businesses are already stretched, it can be tempting to opt for quick, inexpensive fixes. However, poorly executed design or cheap, low quality products can lead to costly, long-term remediation or worse, significant loss to the business. Make wise, informed decisions and specify solutions based on your organisation’s security needs first and foremost. While generic steel palisade is a popular option, owing to its intimidating aesthetic, it is easily compromised. Steel palisade fencing has inherent weaknesses that undermine performance. Its wide pales can obstruct surveillance, while the bolted construction is a huge security risk. Simply removing or breaking the lower fixing on one or two pales would allow them to swing aside to give repeated access to the site without leaving an easily visible sign that the perimeter has been breached. It’s a false economy, as the initial lower price is offset by the costs and inconvenience incurred by regular repairs. Performance classification system The standard works via a performance classification system, and even considers the tools that an intruder may use Specifying a higher quality product that’s fit for purpose makes more sense both in the short and long term, and it adds little to the original cost. Fortunately, there are a number of security accreditations that facilities managers and building owners can refer to when specifying security measures at their site, helping them choose effective solutions to combat the risks the property faces. Proven performance Certifications and approvals, such as The Loss Prevention Certification Board’s (LPCB) LPS 1175 and the British Standards Institution’s (BSI) PAS, prove a product has been thoroughly tested to a specific standard. They prove the strength and durability of the item in multiple different situations. It is worth noting also that investing in effective perimeter protection can actually deliver a positive return by reducing the incidence of burglary and vandalism, and their associated costs. The technical evaluation work carried out by LPCB is extremely thorough. The product is subjected to rigorous quality audit processes, to certify the security products tested by BRE deliver verified levels of protection. All LPS 1175 rated products are vigorously tested before receiving an accreditation. The standard works via a performance classification system, and even considers the tools that an intruder may use. Intrusion detection system Our law enforcement teams are stretched to capacity and coping with reduced workforces due to illness By predicting a likely toolset, specifiers can construct multiple defensive layers to maximise how much time a facility has to respond to an attack. Different levels of security are crucial for the ‘5D defence’ concept, whereby a quintet of security assets work together to prevent access to your site, resulting in a strategy that will: Deter, Detect, Deny, Delay and Defend unwanted access from intruders. 360° security There is no single solution when it comes to securing a building. Every situation must be considered on an individual basis, starting with a full risk assessment. We recommend an integrated approach where appropriate. Along with a secure perimeter, this might also include effective lighting in shaded areas and at doors, gates, and vulnerable windows, Perimeter Intrusion Detection Systems (PIDS) and well-placed CCTV. These measures can hinder entry and escape, or increase the chance of discovery and detection. Domestic burglaries While domestic burglaries have become less attractive as many of our homes are now occupied around the clock, commercial properties have become increasingly more vulnerable. Our law enforcement teams are stretched to capacity and coping with reduced workforces due to isolating and illness. Therefore it has never been so important for building owners and facilities managers to assess the properties they’re responsible for to ensure they’re protected effectively in the event of an attack.

Safety in smart cities: How video surveillance keeps security front and centre
Safety in smart cities: How video surveillance keeps security front and centre

Urban populations are expanding rapidly around the globe, with an expected growth of 1.56 billion by 2040. As the number of people living and working in cities continues to grow, the ability to keep everyone safe is an increasing challenge. However, technology companies are developing products and solutions with these futuristic cities in mind, as the reality is closer than you may think. Solutions that can help to watch over public places and share data insights with city workers and officials are increasingly enabling smart cities to improve the experience and safety of the people who reside there. Rising scope of 5G, AI, IoT and the Cloud The main foundations that underpin smart cities are 5G, Artificial Intelligence (AI), and the Internet of Things (IoT) and the Cloud. Each is equally important, and together, these technologies enable city officials to gather and analyse more detailed insights than ever before. For public safety in particular, having IoT and cloud systems in place will be one of the biggest factors to improving the quality of life for citizens. Smart cities have come a long way in the last few decades, but to truly make a smart city safe, real-time situational awareness and cross-agency collaboration are key areas which must be developed as a priority. Innovative surveillance cameras with integrated IoT Public places need to be safe, whether that is an open park, shopping centre, or the main roads through towns Public places need to be safe, whether that is an open park, shopping centre, or the main roads through towns. From dangerous drivers to terrorist attacks, petty crime on the streets to high profile bank robberies, innovative surveillance cameras with integrated IoT and cloud technologies can go some way to helping respond quickly to, and in some cases even prevent, the most serious incidents. Many existing safety systems in cities rely on aging and in some places legacy technology, such as video surveillance cameras. Many of these also use on-premises systems rather than utilising the benefits of the cloud. Smart programming to deliver greater insights These issues, though not creating a major problem today, do make it more challenging for governments and councils to update their security. Changing every camera in a city is a huge undertaking, but in turn, doing so would enable all cameras to be connected to the cloud, and provide more detailed information which can be analysed by smart programming to deliver greater insights. The physical technologies that are currently present in most urban areas lack the intelligent connectivity, interoperability and integration interfaces that smart cities need. Adopting digital technologies isn’t a luxury, but a necessity. Smart surveillance systems It enables teams to gather data from multiple sources throughout the city in real-time, and be alerted to incidents as soon as they occur. Increased connectivity and collaboration ensures that all teams that need to be aware of a situation are informed instantly. For example, a smart surveillance system can identify when a road accident has occurred. It can not only alert the nearest ambulance to attend the scene, but also the local police force to dispatch officers. An advanced system that can implement road diversions could also close roads around the incident immediately and divert traffic to other routes, keeping everyone moving and avoiding a build-up of vehicles. This is just one example: without digital systems, analysing patterns of vehicle movements to address congestion issues could be compromised, as would the ability to build real-time crime maps and deploy data analytics which make predictive policing and more effective crowd management possible. Cloud-based technologies Cloud-based technologies provide the interoperability, scalability and automation Cloud-based technologies provide the interoperability, scalability and automation that is needed to overcome the limitations of traditional security systems. Using these, smart cities can develop a fully open systems architecture that delivers interoperation with both local and other remote open systems. The intelligence of cloud systems can not only continue to allow for greater insights as technology develops over time, but it can do so with minimal additional infrastructure investment. Smart surveillance in the real world Mexico City has a population of almost 9 million people, but if you include the whole metropolitan area, this number rises sharply to over 21 million in total, making it one of the largest cities on the planet. Seven years ago, the city first introduced its Safe City initiative, and ever since has been developing newer and smarter ways to keep its citizens safe. In particular, its cloud-based security initiative is making a huge impact. Over the past three years, Mexico City has installed 58,000 new video surveillance cameras throughout the city, in public spaces and on transport, all of which are connected to the City’s C5 (Command, Control, Computers, Communications and Citizen Contact) facility. Smart Cities operations The solution enables officers as well as the general public to upload videos via a mobile app to share information quickly, fixed, body-worn and vehicle cameras can also be integrated to provide exceptional insight into the city’s operations. The cloud-based platform can easily be upgraded to include the latest technology innovations such as licence plate reading, behavioural analysis software, video analytics and facial recognition software, which will all continue to bring down crime rates and boost response times to incidents. The right cloud approach Making the shift to cloud-based systems enables smart cities to eliminate dependence on fibre-optic connectivity and take advantage of a variety of Internet and wireless connectivity options that can significantly reduce application and communication infrastructure costs. Smart cities need to be effective in years to come, not just in the present day, or else officials have missed one of the key aspects of a truly smart city. System designers must build technology foundations now that can be easily adapted in the future to support new infrastructure as it becomes available. Open system architecture An open system architecture will also be vital for smart cities to enhance their operations For example, this could include opting for a true cloud application that can support cloud-managed local devices and automate their management. An open system architecture will also be vital for smart cities to enhance their operations and deliver additional value-add services to citizens as greater capabilities become possible in the years to come. The advances today in cloud and IoT technologies are rapid, and city officials and authorities have more options now to develop their smart cities than ever before and crucially, to use these innovations to improve public safety. New safety features Though implementing these cloud-based systems now requires investment, as new safety features are designed, there will be lower costs and challenges associated with introducing these because the basic infrastructure will already exist. Whether that’s gunshot detection or enabling the sharing of video infrastructure and data across multiple agencies in real time, smart video surveillance on cloud-based systems can bring a wealth of the new opportunities.

Biometrics provides industries with security, access control, and data protection
Biometrics provides industries with security, access control, and data protection

Several major players vigorously employ biometric recognition technologies around the globe. Governments use biometrics to control immigration, security, and create national databases of biometric profiles. Being one of the most striking examples, the Indian Aadhaar includes face photos, iris, and fingerprints of about 1.2 billion people. Financial institutions, on their part, make use of biometrics to protect transactions by confirming a client's identity, as well as develop and provide services without clients visiting the office. Besides, biometric technology ensures security and optimises passenger traffic at transport facilities and collects data about customers, and investigates theft and other incidents in retail stores. Widespread use of biometrics Business, which suddenly boosted the development of biometrics, is an active user of biometric technology Business, which suddenly boosted the development of biometrics, is another active user of biometric technology. Industries choose biometric systems, as these systems are impossible to trick in terms of security, access control, and data protection. Being in demand in business, these three tasks are also relevant for the industry. However, the use of biometrics at industrial sites is discussed unfairly seldom. Therefore, it is the face identification that is the most convenient there, as workers often use gloves, or their hands may be contaminated, and the palm pattern is distorted by heavy labour. All these features make it difficult to recognise people by fingerprints or veins and significantly reduce identification reliability. Therefore, industries seek facial recognition solutions. Thus, let us demonstrate the application of face recognition technology at different enterprises, regardless of the area. Facial recognition use in incident management Facial biometric products are known to automate and improve the efficiency of security services by enriching any VMS system. These systems provide an opportunity of instantly informing the operator about recognised or unrecognised people, and their list membership, as well as save all the detected images for further security incident investigation. Furthermore, some sophisticated facial biometric systems even provide an opportunity to build a map of the movements of specific people around a site. Besides, it is relevant not only for conducting investigations but also in countering the spread of the COVID-19 virus. Identifying and tracking COVID-19 positive cases Therefore, if an employee or visitor with a positive COVID-19 test enters a facility, the system will help to track his/her movement and identify his/her specific location. It will also help to take the necessary measures for spot sanitary processing. Thus, the introduction of biometric facial recognition at the industrial enterprise can improve and speed up the incidents’ response and investigations without spending hours watching the video archive. Access control system to secure physical assets The right access control system can help industries secure physical and informational assets The right access control system can help industries secure physical and informational assets, cut personnel costs, and keep employees safe. Facial recognition systems may enrich access control systems of any company by providing more security. As biometric characteristics, by which the system assesses the compliance of a person with the available profiles in the database, cannot be faked or passed. The human factor is also reduced to zero, due to the fact that while identity documents can be changed, the inspector can make a mistake or treat his/her task carelessly, be in collusion with an intruder, the biometric system simply compares a person in front of the camera with the biometric profiles database. Biometric facial identification software For example, RecFaces product Id-Gate, a specialised software product for reliable access control to the site, checks the access rights by using biometric facial identification alone or in conjunction with traditional IDs (electronic passes, access keys, etc.), which means that there is almost a zero probability of passing to the site by someone else's ID. The access control system’s functionality allows one to strictly account the number and time of all the facility’s visitors and also track their movement. When unauthorised access is attempted or a person from the stop list is detected, Id-Gate sends an automatic notification to the access control system and operator. Enhanced data and information security Even despite the division of access to different industrial enterprise areas, the security service needs to provide independent information system security. Employees with the same facility access rights may have different access rights to data. However, in that case, a personal password is not enough, as an employee may forget it, write it down and leave it as a reminder, tell a colleague to do something for him/her during the vacation, or just enter it at another person’s presence. Password-free biometric authentication systems make the procedure user-friendly and secure Password-free biometric authentication Password-free biometric authentication systems make the procedure user-friendly and secure. Such systems usually provide an option of two-step verification when successful password entry is additionally confirmed by biometric recognition. Hence, it is particularly relevant due to the current lockdown in many countries. To sum up, the application of biometric technologies solves several issues of the industry, such as: Optimises and partially automates the work of the security service, as it provides reliable identification and verification of visitors/employees, reduces the amount of time spent on finding a person on video and making a map of his/her movements, without spending hours on watching video archive in case of investigation. Provides a high level of reliability and protection from unauthorised access to the enterprise and the information system. Provides a two-step verification of the user/visitor (including password and biometric data) and almost eliminates the risk of substitution of user data/ID.