WDR technology is an important function for cameras, especially those placed in environments with constantly changing lights.
Currently, WDR surveillance cameras are employed mainly in the banking and finance sectors. Other common applications are parking lots, big plazas, building entrances, ports, tollbooths, and other areas that are frequently affected by varying light patterns and strong backlight. In order to capture detailed images within the areas of surveillance under the ever changing lighting throughout the four seasons, a high-quality WDR camera is needed to fulfill this demand. Not only can this help with ongoing police investigations, but also acts as evidence when disputes occur.
Common Verticals The following provides the main demands for each of the common verticals employing the use of WDR surveillance cameras. End users from different sectors are using WDR technology to overcome many issues that regular cameras with only BLC or low-lux features are unable to address.
Financial Institutions and Banks
In financial institutions and banks, most WDR cameras are installed at all entrances, main halls with floor-to-ceiling windows, armored car driveways, entrances to underground parking garages, ATM locations, etc. in order to provide timely surveillance footage of all visitors and the people and objects both inside and outside of the facilities.
Highway Tollbooths Presently, low-lux WDR surveillance cameras used for traffic monitoring are mainly used in highway tollbooths to watch over toll lanes and monetary transactions at the booths. The cameras are able to effectively monitor the types of incoming cars, the toll collectors' behavior, and analyze and record the possible spontaneous incidents that can occur during the toll collection process. Even in the dark of the night, toll collectors must be able to clearly see the license plate of each car, but under normal circumstances when their headlights are on, the illumination on the highway and reflection from license plates form a high contrast that regular cameras are unable to clearly display. Hence, there is a demand for low-lux WDR cameras in such environments.
Traffic Monitoring Due to the ability to automatically capture those who run a red light, video surveillance helps to raise the level of observation in traffic monitoring centers and also helps to issue commands and responses to immediately mobilize resources to handle any accidents or traffic incidents, and enhance the objectivity of vehicle inspections and violations. Furthermore, surveillance can help to conduct a comprehensive and coordinated control of the roads within the monitored area to further utilize the capacity of the roads. Also, with the need to perform 24-hour surveillance and ALPR/LPR, it is absolutely necessary to employ low-lux WDR cameras in such scenarios.
Commercial Sectors and Areas of Extreme Lighting Many store and shopping center operators will have certain applications where WDR cameras are required. As most of their interior decorations encompass light-reflective floors or translucent infrastructures, the WDR feature is needed to monitor the operation status in and out of the stores, surrounding crowd and traffic flows, and safety conditions as well.
Installation Tips Like any other camera, WDR cameras must be installed correctly in order to perform at its best. Users must also be sure the WDR camera is being used in the right environments. “If you want the WDR technology performing at its fullest potential, the camera needs to be placed in a real WDR setting to activate its features. If you turn on the WDR feature in a normal setting, it will only lower the image resolution,” advised Peter Pan, Product Manager at
Dahua Technology.
“It is especially efficient for entrances, casinos, or any other open space where a strong light source exists. However, if you don't need wide dynamic range technology for a certain scene, it is better to turn it off. This is because it normally has some trade-off in camera performance like sensitivity,” said Miyamaki Hideo, Senior Manager Head of the System Engineering Department in the Visual Security Solutions Business Development Office, APAC at Sony Electronics.
Once the cameras are installed, “contrast enhancement adjustment can help increase the details in the dark parts of the scene within the given dynamic range of cameras,” according to Arnaud Lannes, Product Marketing Manager of
Bosch Security Systems. “Basically, by using a WDR camera, all lighting conditions are covered and it doesn't make sense to adjust the angle of view to obtain a better result. Fundamentally, if the result is better by adjusting the angle of view, that means the camera does not have a wide dynamic range.”
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Future Outlook With a diverse range of applications and users, the technology and categorization of cameras are changing as well. WDR technology is one of the main supporting factors, in a way, representing the potential of technology development and direction of development for camera manufacturers. “In the near future, image sensors supporting WDR will be higher resolution, whilst current megapixel WDR image sensors shall be able to deliver much better images, and have more excellent low-light performance. Moreover, the image clarity during the multi-exposure period will be improved, even with moving objects or individuals in a scene. The ISP for WDR will be improved as well to further adjust to versatile applications and deliver high-quality images with true color reproduction,” predicted Xuehai Yu, IP Camera Product Manager at Hikvision Digital Technology.
WDR technology evolved quickly over the past few years. Dynamic range continued to expand, and now there are even technologies such as dual-speed CCD DSP or dual-speed shutter. All WDR surveillance cameras now use specific DSP circuits, which clearly depicts details captured in the brightest and darkest regions of a scene. “However, if WDR wants to break through its current barriers, costs must be lowered. In the future, if the cost of manufacturing WDR cameras becomes the same as regular cameras, WDR cameras will become very competitive. Like IP-based products, WDR cameras will have to focus on intelligence. WDR cameras in the future will likely be able to automatically turn on/off and adjust its features according to changes in the scene to maintain its dynamic range at its best at all times,” said Pan.
Other manufacturers, such as Bosch, believe that within the next two to three years, there will be multi-megapixel cameras with exceptional wide dynamic range, intelligent auto exposure, and better saturation gain control in WDR technology. Meanwhile, Sony believes the breakthrough will be keeping the best dynamic range of 130dB or higher.
The birth of DPS made wider dynamic range and better color reproduction possible in the new generations of WDR cameras. In the near future, the WDR camera market will be caught in a war between the use of DSP or DPS. Dynamic range is bound to expand with such future prospects.