Page 14 - Security Today, April 2019

For cameras in applications such as sports stadiums, dome cameras can pick out individuals at even greater distances with ex- ceptional clarity. Higher resolutions are also important for playback. For example, when an incident has occurred the operator can zoom into the image to obtain greater detail at a distance.
Recovering Video after a Network Failure
Networks can be vulnerable. When a network goes down, so does the video. However, some cameras allow video to be recorded directly onto the camera’s Secure Digital (SD) card during a network failure. This process is ideal for “brown outs,” when the network is only down for a short amount of time. If the sys- tem is down for days, some video will be lost.
When connectivity is re-established, the recorded video trickles back to the network video recorders and is placed seamlessly into video storage at the correct date and time. However, all the video cannot be transmit- ted at the same time, since this would pre- vent “live” video from being stored. The stored video is transferred from the SD card to the server alongside the live video. The process takes a little longer, but it ensures no video is lost.
Removing the Bubble
Since the days of analog surveillance, the in- dustry has added a polycarbonate-type cover (bubble) around dome cameras. In the early days of IP megapixel cameras, the adverse ef- fect of the bubble was negligible. However, as the resolution of cameras has improved, the quality of the bubble cover cannot keep pace.
After removing the bubble, the megapixel resolution sensors are not hindered and can deliver superior resolution and image quality. The elimination of the bubble has other posi- tive effects. For example, sports stadiums of- ten combine artificial and natural light, which can catch the sides of camera bubbles creating reflections and glares that obscure images. In addition, when dome cameras have built-in infrared illuminators, they are free from any possibility of internal reflection.
By using built-in illuminators, there is a huge saving with respect to installation, op- erational and environmental costs. Since the illuminators are built-in and continually fol- lowingthecamera’sfield,therequirementfor separate illuminators (more lamps, external wiring, time and cost) will be eliminated.
Beyond the issue of illumination as it per- tains to camera bubbles, surveillance equip- ment often has a limited visual field that stops at the horizon. Historically, the middle of the lens has been the clearest area for capturing video. For example, if you place a mini-dome camera on a wall looking down a corridor, due to the nature of the lens it is
possible to have blind spots if the camera can only tilt up to the horizon.
However, advancements in lens capabili- ties are allowing cameras to see clearly even above the horizon. When looking up a high street in a town center with a pan, tilt and zoom lens, many objects will appear just above the horizon and can be clearly seen since they are not obstructed by the edge of the bubble.
The bubble on most dome cameras is not totally spherical. Toward the edge, it flat- tens out before it enters the housing. At this point, the distance can change between the lens and bubble and can impact the focus of the camera.
Improvements in Night Surveillance
We see things because light reflects off ob- jects into our eyes—and surveillance cam- eras are no different. At night, when there is less light to be reflected, the camera will switch from color to monochrome mode. It takes much less light to create a mono- chrome image than a color image projecting hundreds of variations. To further improve the situation, cameras can integrate several frames together, capturing more light from the same scene and creating a clearer image at night.
Color rendition or color matching is important when identifying or following a suspect. The color seen in a surveillance camera’s image must be the same as what the human eye sees. Capturing true color in bright sunlight is relatively easy. However, capturing multiple types of light levels and light sources experienced during a 24-hour period takes great skill. Innovative engineer- ing has given some cameras the ability to en- sure the colors are a precise match.
Many features and functions on a cam-
era are programmed for an optimal setting at the time of installation and then typically left until the next service call or customer re- quest. This setting may be ideal most of the time, but because the environment the cam- era works in changes on a constant basis, it is not completely reliable. New technology al- lows cameras to automatically adjust “white balance” to maintain the optimum image quality 24/7 without the need for operator interaction.
Future of Video Surveillance
Machine learning capabilities are currently being added to video management systems and network video recorders to take the rich data obtained by IP cameras and translate it into actionable intelligence. We are starting to see technology that allows video surveil- lance tools to differentiate between objects and people as well as being able to configure themselves based on a scene’s requirements.
While video surveillance and its integration with the Internet of Things (IOT) are currently focused on residential spaces, it is now making its way into commercial applications as a part of building enterprise management. A surveil- lance camera is a sensor that creates data, and its optical sensors create huge potential for commercial buildings, including heating, light- ing, HVAC, parking, etc. This data can be fed intothebuildingmanagementsystemtohelp facility managers, operation managers, HR managers and others maintain a building at peak performance.
Peter Ainsworth is the product general manager, Video Products Global Building Technologies and Solutions, Security Prod- ucts at Johnson Controls.
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