CCTV – Technical Advancements
CCTV, as most of you would be aware, is a surveillance technique used to monitor a destination remotely by the help of close circuit TV cameras. It has proved to be a useful technique and is employed extensively to prevent crimes, thefts and burglaries. It has also found application in traffic control, transport safety and in industrial processes where there are certain areas which are harmful for human beings.
From the time CCTV technology first appeared on the scene it has undergone many technological improvements. Not only the cost of such systems has dropped significantly, they are able to provide much better surveillance with improved clarity of vision.
The initial CCTV cameras were simple black and white low resolution cameras without any features to zoom or pan (Pan is the ability of a camera to move in horizontal direction or rotate). But nowadays the cameras that are being used in high end systems are high resolution, high color definition cameras having features such as automatic focus to resolve finer details, higher order zoom and panning. The digital output from these cameras is presented to a computer dedicated for image processing which can automatically track the objects. This technology of identifying and tracking objects in a live video feed is called VCA (video content analysis) and is currently being worked upon by many technological companies.
With the ever increasing processing power of computers it has become possible to apply various processing algorithms on feed from the cameras to identify whether the moving object is a walking person, crawling species or an automobile. Color of an object can also be identified easily.
NEC, a Japanese corporation, claims that they have a ready system which can work out the age of a person in an image!
In many situations along with monitoring we need additional requirements to be fulfilled by the CCTV system. For example we may need to sound an alarm if a person tries to move towards a restricted zone or we may need to set off an alarm when any object is displaced from its real position or when any object has been left unattended for a specified period of time. In all such cases VCA could be of a great help. Also there are great applications of VCA in forensics as it can be used to extract all the possible evidences from the footage of a CCTV.
There has been a new development in the field of CCTV known by the name of CCDP (close circuit digital photography). In this technique instead of a continuous video feed, high resolution 1600X1200 pixel still images are captured continuously after a short time span or on a motion detection basis. The main advantage of this technology is that better resolution is available from the same digital camera which can be used more effectively for analyzing and identifying the objects. The storage space required is also less and these continuous shots can be arranged to form a Pseudo video format. Using this CCDP software relatively low cost camera can also be used for CCTV purposes.