The architecture and features of CCTV systems has been radically altered by the introduction of digital signal processing and digital circuitry. Although the end product is still a video image, every element in the process has undergone revision and redefinition.
- The processes which occur in a video system are:
- Image (data) acquisition (the camera).
- Image (data) processing (data optimization for viewing, transmission and storage).
- Image (data) transmission.
- Image (data) archiving.
SD readers who are already familiar with VCRs and DVRs probably agree that is unfair to compare analog to digital technologies. Although market research and sales figures indicate that the cost of digital cameras is considered by many to be too high for most applications, DVRs are a different story. DVRs are offered in many configurations and at many price points. This makes them an attractive alternative for both new installations as well as retrofits.
DVRs allow live video and/or previously recorded video to be viewed through the Internet. They can be set to record only motion events. They reduce storage space and playback time needed. They reduce unproductive time reviewing hours of uneventful camera views. DVRs can have support for external CD burners, DVD burners, hard drives. Some units have CD burners in them. They can also write to other portable storage media.
Multiplexers are usually built into the unit. DVRs offer alarm features including motion sensing, alarm triggers, e-mail notification and PDA accessibility. There is also the option of a user selectable frame per second control for individual cameras in the digital video recorder system. Units with PTZ camera support permit off-site remote control of PTZ parameters.
DVRs save space because no tapes need to be stored when using a digital video recorder. Some 60 days of videocassette storage takes space and money whereas 60 days of disks can fit in a drawer. Since functionality is consolidated into a single DVR unit, the footprint of the surveillance system is substantially reduced, as are the power requirements. DVRs are available for one camera or numerous cameras. They are also scalable allowing distributed acquisition, monitoring, processing, and archiving.
DVRs are highly connective. Models can communicate with remote viewers, servers and storage over a variety of generic protocols. DVRs are able to accept inputs from conventional analog video cameras and other hardware as well as digital cameras.
After reviewing the capabilities of DVRs and digital processing, the old way of referring to surveillance as CCTV is a really inadequate. It should be replaced with a term that will differentiate Closed Circuit Television from what’s actually happening in the technology. Security Dealer refers to it in general terms as video surveillance and uses the expression “New Video.” It seems to be catching on.
The topology of a New Video system has become relatively streamlined and simplified as compared to the conventional analog system, even though the DVR technologies are infinitely more complex. The DVR user-interfaces strive to be intuitive. DVR image quality can be tailored to the topology and infrastructure of the system, and to the specific application.
The opportunities for DVR applications seem boundless. The selection of DVRs presented here offer features which are representative of the product group.
Remote connectivity is a feature everyone is talking about in today’s models. Integral Technologies’ RemoteView, for instance, is an application that allows users to view live and recorded video, manage their systems remotely, and operate a host of features from any Integral DVMS unit, which includes the enterprise-class DigitalSENTRY system and the robust MasterControl DVX system. RemoteView is a single interface, user-friendly application that is easily installed and operated from any remote client PC. Virtually any number of users can simultaneously access single or multiple systems, making it a powerful, remote viewing tool.