Digital video makes surveillance a snap. At your fingertips are control functions (pan-tilt-zoom, recording, etc.) and limitless remote monitoring options.
The advent of digital signal processing technology and its rise to fame began in consumer markets, and this innovation continues to find its way to the security and surveillance market, with more to come.
Closed circuit television (CCTV) systems are not end-to-end digital. Currently, the signal between the camera and the head-end (recording) equipment is still analog. There are many ways to transmit the signal—such as wireless, standard cable, fiber optics and unshielded twisted pair (UTP)—but currently, there is no way to send a digital signal for any distance. Once that happens, then surveillance systems will become completely digital.
Surveillance installations continue to outpace most other categories of security products, according to trade publication Security Distributing & Marketing magazine. Based on a recent study, low-voltage installers say 18 percent of their revenues were from CCTV; they also say it is often partnered with access control in integrated systems.
Here’s the latest news on CCTV, much of which is attributable to digital signal processing:
Cameras are smaller, smarter and able to “see” in some of the lowest light levels ever; some see in the dark with special illuminators. One of the most significant developments has been in day/night technology, said Jon Mitchell, marketing assistant, Crest Electronics Inc., Greensboro, N.C.
“Day/night technology allows the unit to operate in color during the day, and if there is not enough light available on site during the night, the camera will transmit in black and white. This allows for improved surveillance during all lighting conditions. In the past, a person had to decide whether to go with a black and white or a color system, but now one camera can handle all conditions.”
Remote surveillance is a big draw for CCTV, so it makes sense that manufacturers continue to concentrate their research and development dollars on extending the realm of this function. Mitchell comments that digital allows the customer immediate access to remote facilities. “With a digital system, a manager in New York can see what is going on at his company’s manufacturing facility in California, for example, in virtual real time, thanks to TCP/IP addressing. It also allows them to review events without having to travel to the site,” he said.
Digital network cameras with built-in Web servers are entering the mainstream.
“With a network connection, such as the Ethernet or a local area network (LAN), some cameras can be directly connected to the Internet without a computer, operating as if they have a built-in PC,” said Dave Walton, national marketing communications manager, JVC Professional Products Co., Wayne, N.J. “Control and viewing can now be accomplished not only from a local network, but from anywhere on the Internet.”
Transmission over the Web, LANs and wide area networks (WANs) will continue to evolve as the Web becomes more sophisticated as a transmission system, according to Michael Shatzkin, director of marketing, CSI-Speco, Amityville, N.Y. “Right now, networking over the Web or a LAN can yield somewhat choppy images.”
Color and black and white cameras continue to drop in price, with color leading the charge. Most security professionals maintain that color is most appropriate when identification is key, i.e., the man with a red shirt and black car was seen leaving the parking lot with the stolen merchandise in hand. Don’t overdue is the lesson here. Black and white is still appropriate for applications where positive identification is not required.
Digital video recorders (DVRs) are also smaller, more affordable and able to capture images with stark realism.
Labor savings in playback time and more efficient search capabilities is key to DVR innovation. No longer do security personnel or management have to dredge through hours of tape looking for incidents. By recording to a digital medium, you eliminate some of the biggest problems with videocassette recorders and tape systems, including recording degradation, search capability and down time. And, with digital recorders, maintenance is virtually nonexistent.
More sophisticated DVRs with higher-grade recording are also propelling the evolution of higher-resolution cameras, some with as much as 470 to 480 lines of resolution.
If you need to monitor a remote location from headquarters or to add another site to a networked system over a LAN or WAN, CCTV surveillance can handle virtually any such thing, thanks in part to digital signal processing. EC
O’MARA is the president of DLO Communications in Park Ridge, Ill., specializing in low-voltage. She can be reached at either 847.384.1916 or firstname.lastname@example.org.