Application of infrared camera night vision monitoring technology

In recent years, with the development of economy, people have paid more and more attention to the protection of property and personal safety. The deployment of video surveillance is one of the most common security measures. At present, 24-hour day-night surveillance has been widely adopted. Infrared cameras have been highlighted for their night-time surveillance, and they have become even more popular in the field of security. This paper is favored by many users. The reader will analyze the application status of infrared cameras and technology development trends.

After more than two decades of rapid development, the security industry has received increasing attention from the country and society. Since 2000, infrared cameras have emerged as a new concept product in the Chinese market on a large scale. From scratch, from bulky to exquisite and compact, the irradiation distance is also from near to far, and technological development has gradually become “integrated” with the market. Occupancy increased year by year. Mao Manji, technical engineer of Tianjin Samsung Taike Optoelectronics Co., Ltd., said that the reduction in the technical threshold of infrared camera product lines, the increase in the supply of core components and raw materials, and the increasing monitoring and security awareness in the civilian market have all contributed to the infra-red camera’s insensitivity to lightning. The speed of the ear has quickly occupied the market. In recent years, the launch of some large-scale domestic projects has also played a role in the development of the infrared night vision market. Samsung engineers analyzed that since monitoring is the basic measure of security, along with the development of the industry, security technology has been increasingly valued by all sectors of society, security monitoring has gradually become a focus of social demand, these external factors Is driving the infrared night vision market continues to heat up.

Common infrared cameras can be divided into two categories, active infrared cameras and passive infrared cameras. Zhang Xu, product manager of Hangzhou Hikvision Digital Technology Co., Ltd. introduced that the former mainly uses active infrared light to fill and monitor the scene, and the latter uses the infrared light emitted by the monitored object itself to image the scene. Or an infrared technology that depends on the infrared radiation of the detected object to achieve imaging and monitoring, based on the temperature difference or thermal radiation difference between the target and the background or parts of the target, to generate a thermal image to find the target. On the basis of thermal images can also be converted into video images, the product is called infrared Thermal Imaging Camera. The active infrared night vision technology is a kind of night vision technology that realizes monitoring by using infrared light that is actively emitted by infrared light, and there are LED infrared and laser infrared products.

Digital China (China) Co., Ltd. AMPON product manager Lan Liu also believes that the current security camera on the market mainly use low-intensity, low noise CCD as a photosensitive component. According to the arrangement of infrared lamps and structural components, infrared night vision cameras can be divided into infrared camera, dual filter infrared camera, dual CCD infrared camera, array infrared cameras and other types. With the advent of high-definition cameras, high-definition CMOS infrared cameras have also been widely used.

Infrared cameras from the early development of analog infrared cameras to high-definition network infrared cameras and even high-definition digital SDI infrared cameras, the main change is the image acquisition, transmission processing, lens, infrared light these four core components. Tianwei Weiye Digital Technology Co., Ltd. Digital front-end product manager Mark Wei said that infrared camera and development, has been relatively mature, but there are still several technical difficulties are the industry manufacturers are trying to improve.

1, waterproof and heat dissipation effects, after use, the camera will appear inside the water vapor, waterproof poor problem is mainly structural seal problems, good sealing can effectively control the emergence of the problem, and infrared LED camera heat dissipation is very important, The problem of headaches, now technically, will generally adopt the second type of approach. First, change the power supply, use a constant current power supply to control the heat generation of the LED, and second, select a material with good heat dissipation effect and a reasonable heat dissipation structure, such as LED Lamp panels and enclosures use aluminum alloys and other heat-dissipating materials and maximize the metal heat dissipation surface. Auxiliary methods have a reasonable arrangement of LED lights to reduce heat concentration so as to affect the CCD life.

2, poor night vision, the main performance is the lack of infrared light distance and infrared flashlight effect, the current manufacturers are using array-type LED for improvement and upgrading.

3, daytime color distortion color cast. At present, most infrared cameras use double filter switching devices to fundamentally solve this problem.

4, repeated changes in the critical point of illumination. The double filters used by some manufacturers' infrared cameras are not stable when the illuminance reaches the color to black critical value. This is because there is no delay mechanism in the design process, resulting in repeated switching of double filters and image color to black.

Low light, thermal imaging technology is also sought after

As we all know, with the development of optoelectronic information, microelectronics, network communications, digital video, multimedia technology and sensor technology, security monitoring technology is moving from traditional analog to highly integrated digital, intelligent, and networked. With the increase of market demand, modern high-tech has almost applied or is about to be applied in the security monitoring system. Among them, the micro-light technology and infrared thermal imaging technology have also been applied in the security system.

Wu Yingying, IP product manager of Marketing Department of Infino Technology Co., Ltd., introduced that low-light night vision monitoring technology is the use of vacuum and electro-optical technologies to convert photon images, electronic images, and visual video images. The enhanced technology of electronic images to achieve visual enhancement of images, and then to achieve a night vision technology in the presence of weak light. The advantage is that the viewing distance is relatively long. The disadvantage is that the object cannot be seen clearly without light. This is the reason that this technology needs to be in a certain light, even under a low-light environment, as far as infrared technology is concerned. See the image of the surveillance scene.

The thermal imaging technology is a kind of passive infrared night vision technology. Ordinary infrared monitoring technology is active infrared night vision technology. The thermal imaging technology uses the difference of the infrared heat radiation intensity in different parts of the natural world to form an image. It is based on the target and the background or Find the target by the difference in temperature or thermal radiation between the various parts of the target. Since this technology does not change with changes in ambient light conditions, video images can be provided during day and night, even in severe environments such as heavy fog and rain. However, it can not achieve long-distance monitoring, and the monitoring screen can only determine whether there are suspicious people to enter, and can not see the face and appearance characteristics.

Ordinary infrared camera is an active infrared technology. It is a kind of night vision technology that uses active reflection of infrared light to achieve camera monitoring. With the application of the third generation of infrared array technology, the effect of active infrared monitoring has been It has been greatly improved, the product quality and life are also better, and the manufacturing process is not required, the cost is low, and it has a broad application prospect.

Low-light night vision and thermal imaging technology are similar in practical application. The cameras of these two technologies are mainly used in night-time and special surveillance sites with certain requirements for the concealment of the equipment, such as military, criminal investigation, anti-drug and privacy protection, etc. The two devices are very suitable for such monitoring sites. Tian Weiye’s Mark Kewei said that the low-light night vision camera is to enhance the electronic image generated by weak natural light to a video image that can be effectively monitored to monitor the scene. The thermal imaging technology works by using the principle that objects above absolute temperature zero (-273°C) can radiate infrared light. Since infrared radiation heat intensity of various objects is different, all objects of humans, animals and scenes are Can be clearly observed, and not affected by obstacles such as smoke, fog and grass, can work day and night. Infrared cameras are often said to be active infrared, that is, the use of infrared beam fill light, the target is not limited, all black can also be used, the effect is good and the price is appropriate, but the fill light distance is limited, the concealment is not Strong, vulnerable to weather and other factors, and various types of targets on the reflection of infrared light have great differences, these will affect the image quality.

At present, infrared thermal imaging technology is more widely used in security than that of low-light imaging technology. Xue Shengyue, market manager of Dali, analyzes and summarizes the specific applications of infrared thermal imaging in the following points.

1. Monitoring of targets at night and in adverse weather conditions

On nights when they are out of sight, visible light-based surveillance equipment is no longer functional. If artificial lighting is used, the target is easily exposed. If low-vision night vision equipment is used, it also works in the visible light range and still requires weak light illumination from outside. The infrared Thermal Imager passively accepts the target's own infrared thermal radiation, and can work normally both during the day and night, and will not expose itself. Even under adverse weather conditions such as rain and fog, due to the short wavelength of visible light, the ability to overcome obstacles is poor, so the observation effect is poor, but the wavelength of infrared rays is long, especially in thermal imagers working on 8-14 um. The ability of rain and fog is high, so the target can still be observed normally. Therefore, at night, especially under severe weather conditions, infrared thermal imaging monitoring equipment can monitor various targets such as people and vehicles.

2, fire monitoring

Since the infrared thermal imager is an imaging device that reflects the surface temperature of an object, it can be used as an effective fire detection device in addition to being used as a site monitor at night. The use of infrared thermal imager can quickly and effectively find these hidden flames, and can accurately determine the location and scope of the fire, through the smoke found that the fire point, so that as early as possible to prevent early, extinguish as early as possible.

3, camouflage and hidden target recognition

Common camouflage is based on preventing visible light observations. The crimes committed by ordinary criminals are usually hidden in the grass and forests. Due to the harsh environment and human visual illusions, it is easy to make erroneous judgments. The infrared thermal imaging device passively accepts the target's own thermal radiation, and the temperature and infrared radiation of the human body and the vehicle are generally much larger than the temperature and infrared radiation of the vegetation. Therefore, the target is not easy to disguise and is not easily misjudged.

4. Application of infrared thermal imaging inspection and quarantine

In recent years, airport aeronautical business has developed rapidly. There are more than a thousand passengers entering and leaving the country each day. The number of people entering and leaving the country’s borders and exits and entrances is heavy, busy and crowded, and the situation is complex. The inspection and quarantine tasks for immigration personnel are corresponding to this task. Very heavy. At the same time, in recent years, with the epidemic and ravages of infectious diseases such as SARS and bird flu, the traditional inspection and quarantine work is facing increasingly severe challenges. In order to ensure safe and smooth customs clearance for entry and exit passengers in the new situation, innovative thinking and innovative methods are required. The use of infrared body temperature monitoring systems with a relatively high degree of automation is a better technology choice.

Network innovation

As a monitoring front-end device, the development direction of infrared cameras is also the same as other types of cameras, and it is developed around several aspects such as networking, high-definition and intelligentization. In addition, if you can better integrate with the relevant infrared technology, it will undoubtedly greatly improve the overall camera quality of the infrared camera, more and better meet the needs of users. It is believed that in the near future, under the trend of increasing integration of many smart technologies today, the working capability of infrared cameras will surely be substantially improved, bringing a new model to our security work.

The networking, high-definition and intelligentization of security products have become an inevitable trend in the industry. In the face of changes in the product system architecture, infrared cameras are also bound to need corresponding improvements. Because most high-definition cameras use CMOS sensors, the noise of the video they monitor at night is relatively large. How to solve the problem of large noise in the night and the occurrence of snowflakes in the video in the infrared high-definition camera has become a key issue.

With regard to the impact of the industry's networking trend on infrared cameras, Guo Junwei, product manager of Kodak, said that the development of IP-based and high-definition security products has enabled infrared cameras to have such features and has greatly facilitated the use of infrared cameras. . Such as IP-based infrared cameras to facilitate the deployment of more convenient, more intelligent; high-definition infrared cameras so that night surveillance images are also more clear, you can show more details, Kodak has launched a high-definition infrared network hemisphere, high-definition infrared network waterproof machine, And high-definition laser network platform, very popular with users.

Conclusion

With the rapid development of infrared technology and the demand from the security application market, infrared cameras will have further development. Infineon’s Wu Yingying stated that the third-generation infrared array technology has improved energy efficiency, reduced temperature and power consumption from the technical point of view, and initially alleviated the issues such as heat dissipation and longevity. Intelligent infrared and adjustable focus technologies can effectively enhance infrared imaging. effect. In terms of cost, infrared cameras have lower costs than high-end low-light, wide-dynamic, and wide-motion camera technologies and can be used in large-scale applications. From the perspective of market demand, 24-hour monitoring has basically become a fixed trend, especially as a front-end device for monitoring, infrared cameras. The direction of development is also similar to that of other types of video cameras. It is centered on the following aspects: network, high-definition, and intelligent.

It is believed that in the near future, under the trend of increasing integration of many smart technologies today, the working capability of infrared cameras will surely be substantially improved, bringing a new model to our security work. In the high-end community, intelligent buildings, campus monitoring, prisons and other fields, many high-end customers have gradually changed the concept of infrared is a low-end, began to use infrared camera products on a large scale, in order to better meet market demand, manufacturers have been optimistic about the development of the infrared product market In order to launch a series of infrared camera products, I believe that infrared cameras in 2012 will inevitably usher in a better development prospects.