siliconindia | | December 20198TECHNOLOGICAL EMERGENCE OF SECURITY CAMERASBy Manish Agarwal, Director, Secureyes per the today's changing environment and scenario, se-curity cameras are the need of every household, every office, every building and every so-ciety. Though with the emer-gence of technology, security camer-as have also traversed a long distance while adopting various technologies. Let's know everything about Security cameras to clarify your basics. Secu-rity cameras are either analogue or digital which means they work on the basis of sending analogue or digital signals to a storage device such as a video tape recorder or desktop com-puter or laptop.Analogue Cameras/DVRAnalogue Cameras basically allows you to record straight to a video tape recorder which is able to record an-alogue signals as pictures. Analogue signals can be converted to digital signals to enable the recording to be stored in PC as digital recordings. In that case, the analogue camera must be directly plugged into a vid-eo capture card in the computer, and the card then converts the analogue signal to digital. These cards are rel-atively cheap, but inevitably result-ing digital signals compressed 5:1 (MPEG Compression) in order for the video recordings to be saved on a continuous basis.Another way to store recordings on a non-analogue media is through the use of a digital video recorder (DVR). Such a device is similar in functionality to a PC with a capture card and appropriate video recording software. Unlike PCs, most DVRs designed for CCTV are embedded devices that require less maintenance and simpler set up than a PC based solutions, for a medium to large num-ber of analogue cameras.Some DVRs also follow digital broadcasting of the video signal, thus acting like a network camera. If a de-vice does allow broadcasting of the video, but does not record it, then it's called a video server. These devices effectively turn any analogue camera into a network TV.Digital CamerasDigital Cameras do not require a vid-eo capture card because they work using a digital signal which can be saved directly to a computer. The sig-nal is compressed 5:1, but DVD qual-ity can be achieved with more com-pression. The highest picture quality of DVD is only slightly lower than the quality of basis 5:1 compression DV.Saving uncompressed digital recordings take-up an enormous amount of hard drive space, and a few hours of uncompressed video could quickly fill-up a hard drive. Holiday uncompressed recordings may look fine, but one could not run uncompressed quality recordings on a continuous basis. Motion detec-tion is therefore sometimes used as a work around solution to record in uncompressed quality.However, in any situation where standard-definition video cameras are used, the quality is going to be poor because the maximum pixel reso-lution of the image chips in most of these devices is 320,000 pixels (ana-logue quality is measured in TV lines but the results are the same). They generally capture horizontal and ver-tical fields of lines and blend them together to make a single frame. The maximum frame rate is normally 30 frames per second.Network IP CamerasIP cameras or network cameras are analogue or digital video camer-as, plus an embedded video serv-er having an IP address, capable of streaming the video. Because net-work cameras are embedded de-vices, and do not need to output an analogue signal, resolutions higher than CCTV analogue cameras are possible. A typical analogue CCTV camera has a PAL (768 x 576 pixels) or NTSC (720 x 480 pixels), where-as normal cameras may have VGA Responsible majorly for expanding Product Planning and Stock Availability, Manish takes care of Operations, Finance, Manufacturing, and Marketing functions at Secureye.IN MY OPINIONA
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