Spatial Resolution
CCTV cameras have been based around the standard Broadcast specifications (PAL in Europe and NTSC in the USA). This gives a maximum spatial resolution of just under 800 x 600 pixels, which in many cases is enough to show that someone is committing a crime, but not enough resolution to be able to positively identify them. Research published by the Scarman Institute for the UK Home Office has shown that Criminals do not worry much about a CCTV camera, as they know it is ineffective.
Human Interface
Historically many CCTV solutions have been essentially a forensic tool; the video has been recorded but not monitored. This hopefully allows the system to go back after an incident has occurred to see what happens. However, the incident has occurred and therefore there is no element of crime prevention. Given the problems of spatial resolution along with the use of hooded tops, masks etc. it is very common for it to be impossible to recognise the perpetrator, thereby rending the system useless.
Some systems (especially those monitoring town centres) relay the information back to a Control Room. However in almost every case it is expected that one Security Officer has to watch many cameras, meaning that his attention to any camera is at best very limited and in reality non existent.
Inflexibility
The requirement to transmit live video to either a recorder or to a video wall has required fixed installations with very expensive installation costs. The actual cost of the camera is less than 5% of the total hardware and installation cost required to receive the data at the video monitor or DVR. The need for fixed cables has prevented the use of temporary cameras to monitor “hotspots” which can come and go very quickly as Police and Security Guard assets are deployed in response to the problems.
Recently the CCTV market has seen the introduction of new technologies that aim to overcome some or all of these deficiencies.
High Resolution Video over IP or Digital Video
By moving into the digital domain it is possible to circumvent the restrictions of the analogue TV specification, there are cameras out in the market, which have moved to spatial resolutions of 2000 x 1500 pixels, although the frame rate is lower. This increases the resolution by over 6 times against a PAL camera, but this technology fails to address the other 2 deficiencies. It should be noted however that most Video over IP cameras on the market today offer lower resolutions than standard analogue CCTV, they just make use of existing IT cabling infrastructure rather than the need to install dedicated analogue cables.
Behavioural Recognition Software or Video Content Analysis
Computer Science is now building algorithms, which will automatically monitor the incoming video and report only the unusual. This frees the security officer from having to monitor the mundane 99+% of incoming CCTV where nothing of interest is happening. He can then spend his time productively doing other jobs, in the knowledge that the system will alert him and deliver video to his desktop if and when he needs to react and make decisions. However while these algorithms can work on both PAL and High Resolution images the image analysis computer still requires all of the video feeds to be hardwired back to it, making it inflexible.
Smart CCTV Cameras
There is no reason why a camera should only be an image acquisition device; by building a microprocessor into the camera, Video Content analysis can take place locally without the need to transmit large packets of image data around from every camera. This means that video is only transmitted when required, from only one or two cameras in the system. The amount of data can be further reduced, Automatic Number Plate reading software (for example) in the camera would allow just a text string of the number plate (a few bytes of data) to be sent as opposed to complete images. By reducing the dataset it becomes possible to use radio frequency communications from Bluetooth through WiFi to Microwave and thereby remove the requirement to install cables.
This ability to release CCTV from the constraints of a fixed infrastructure allows the cost effective deployment of temporary surveillance of anti social and criminal hot spots, which if a fixed solution is installed tend to move around the corner. The use of Smart CCTV cameras will open up many new methods of dealing with criminal and anti social behavioural problems which have been impossible to solve until now.
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© Smart CCTV Limited 2006 – All right reserved. For more information on Smart CCTV Limited please visit our web site: www.smartcctvltd.com - Published by: Nick Hewitson
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