Centralized intelligence - This is most common in a system utilizing DVRs to convert and store video from analog cameras. In this type of system, all IV algorithms are housed at the DVR level along with digitization of the video and video management functionality. In this set up, all computing power is centralized in the DVR, which means the number of cameras that can be analyzed is limited, making the system less scalable.
Distributed intelligence - Distributed intelligence can be used in a network video system using analog or network cameras. If analog cameras are already installed, video servers can be added to the system and used to digitize analog video and run IV algorithms closer to the camera level. The processed information is then funneled through a network switch to storage devices and monitoring stations.
In a network video system the edge devices -- the video servers or the network cameras themselves -- have built in computing power to run the IV algorithms, pushing the intelligence all the way to the periphery of the surveillance system. This makes the system scale from one to thousands of cameras without over burdening the centralized recording device, like in the DVR scenario. It also decreases the amount of video sent over the network because the cameras themselves "decide" when recording is necessary. This in turn reduces the overall strain on the IT infrastructure by freeing up bandwidth for other applications.
IV and Image Quality
Along with the mathematical algorithms, image quality is of extreme importance for the accuracy of the IV system. Without clear images, the best IV algorithms will not be able operate accurately. Network cameras bring an end to the interlaced scan problems of analog systems utilizing DVR technology. Interlaced images are created from two sets of lines that update alternately. This delay causes a blurring of the overall image. Network cameras utilize a newer technology to create images called progressive scan. Progressive scan captures the entire image at once, so even with a high degree of object motion, the image is clear.
Megapixel and Immersive Imaging
Analog video systems are tied to television specifications, meaning the maximum resolution is 0.4 megapixels when digitized. Standard digital still cameras available at retail stores are now 5 megapixels and 1.3 megapixel cameras are built into cell phones. Network video cameras can also utilize megapixel technology, which has some obvious benefits, beyond just getting a clearer image. Details from megapixel cameras are more easily recognized in the image. More details means additional data points for IV algorithms, which in-turn improves accuracy of the analytics.
Another way to utilize megapixel technology is for what's being called "immersive imaging". By using a wide-angle lens attached to a megapixel camera, the camera can span a much wider field of view (some camera lenses designs even cover a full 360 degrees) than normal cameras. Immersive imaging facilitates digital pan/tilt/zoom (PTZ). The result is the ability to pan, tilt and zoom in on a field of view, even though the camera stays put. Because there are no moving parts, users don't experience the mechanical wear and tear that exists in analog PTZ cameras which must physically move There's also a potential gain in speed, since an analog/mechanical PTZ can be no faster than its drive motor.
IV, megapixel and immersive imaging offer a number of benefits to an existing or new surveillance system. IV can lower the total cost of a surveillance system by generating fewer false alarms, and by reducing the amount of people required to operate the system. The surveillance system will alert personnel as appropriate when an unusual event occurs. Megapixel imaging allows for even higher resolutions, which in turn allow IV algorithms to act even more exactly.
To be most effective it is critical to work with vendors that employ open standards for the use of IV. This allows the user to choose the best IV algorithms and applications for their needs without having to worry about interoperability challenges.
IV, megapixel and immersive imaging remain hot because they will greatly improve system performance and will continue to evolve creating even greater user advantages in the coming years. Network video is a best of breed system, utilizing open computing platforms and storage systems, which will result in new hot technologies on the horizon faster than usual.