DVR stands for digital video recorder. It records video digitally onto a hard disk. DVRs may be stand-alone, they may be connected to a PC, or they may be connected to a television, cable, or satellite system. They come in a variety of sizes, from small and portable, to industrial and commercial size – primarily for recording large amounts of data within a DVR surveillance system. Software is included with DVR systems to extract video from the hard disk for playback.
Rather than using analog VCRs, DVR surveillance systems use digital cameras, which, rather than recording an image onto video tape, creates a digital file that doesn’t degrade with time. The quality of the images in the digital video will depend on the quality of the camera recording it. There exist DVR systems that can store more than 30 days worth of video footage. These systems are geared toward commercial businesses and at frequent travelers, because they let you watch video when you need to, and with some systems, they let you watch video over the internet.
There are three types of DVR surveillance systems:
1. Systems that use DVR cards
2. Systems that use a DVR interface
3. Systems that use a dedicated DVR connected to a PC
Because of the small size necessary for DVR surveillance systems components, they can be easily customized to suit the needs of a home, a store, or an entire large office complex, shopping mall, or other public place. For basic home or small retail DVR surveillance systems, setting up involves basically installing a DVR card in a PC. The 4-channel cards with 60 frames per second (FPS) cost under US$100, with higher prices corresponding to higher numbers of channels and more frames per second. The top end cards cost up to $7,000.
DVR surveillance systems can be integrated with point-of-sale terminals, and can be made bulletproof. Systems can hold up to 6 terabytes of data. Other features that can be added include two-way voice communication, remote internet video monitoring, real-time live DVR streaming, wireless, hand held PDA viewing, watermarking for law enforcement purposes, and automatic archival.
This type of system is coming into common use in India, allowing authorities to catch more criminals. These DVR surveillance systems can be used to track criminals; recording ongoing movements help police give chase. These systems are much easier to install than old systems, and CCTV-India, the security company, offers low cost support services. More than 60% of India’s population of 1.1 billion relay on CCTV cameras for security.
Other places around the globe are jumping on the DVR surveillance system bandwagon as well. They are easy enough to install those private citizens and business owners can easily put up such a system to monitor their homes or places of business. The steps involved in setting up a DVR security camera are very straightforward. But first you need to choose the right equipment.
Determine how much video you want to store at any one time, and what your budget is. It is important to note that most DVR surveillance systems are Windows based. If you want a dedicated DVR so you can store the largest amount of data, these systems are easiest to set up and come with their own monitor, but they are your most expensive option. Alternatively, you can buy a DVR card to turn your PC into a DVR surveillance system. The cards are only about half the cost of the dedicated DVR, but you may need to enlist in the help of a professional to install the card in your computer.
Your least expensive option is to buy a DVD interface, which hooks up to your computer with a USB cable. They don’t hold as much data as the other options, but they hold enough for the average home DVD surveillance system. If you’re using a wired system, you’ll need to choose a DVR with enough ports that you can connect the number of cameras that you want to use. You’ll need to install the software that comes with a DVR or a DVR interface according to the instructions that come with it.
1. The first step is determining where you want to install the cameras in your home or business. In stores, cameras should be focused on cash registers. In homes, cameras should focus on points of entry and areas where valuable items are kept.
2. You can mount the cameras high on walls or on ceilings, or you can place them atop a tall piece of furniture like a wardrobe. The higher the camera is located, the wider the viewing angle and the fewer the blind spots.
3. For wired DVR surveillance systems, run wires from the camera to the DVR. This usually takes one wire per camera, because the one wire carries signal and power. You should hide wires for reasons of aesthetics and discretion. They should be routed along baseboards on the floor to prevent tripping.
4. If you’re using a wireless surveillance system, plug the receiver into the DVR. Plug each camera into an electrical outlet.
Many people have questions on the legality of DVR surveillance video recording in their home. Generally speaking, if you are not videotaping areas where people have a reasonable expectation of privacy, such as bathrooms and changing rooms, it’s OK to use cameras for surveillance. Selling any video captured on the system would be on shaky ground legally, particularly if someone captured in the video objected.
As for video captured in public places in the U.S., though some people believe that video captured in public that is used for criminal prosecut ion is a violation of the Fourth Amendment to the U.S. Constitution, there aren’t very many laws covering the use of video captured in public places. When DVR surveillance systems are used in a way that a person could easily and freely view the same image or person if they were actually on the premises, then there is no invasion of privacy.
Camera technology is improving along with DVR surveillance systems. For example, Toshiba recently released the IK-WB30A IP network camera with a two megapixel CMOS sensor. It’s the highest resolution IP camera yet introduced by Toshiba, and can transmit thumbnails of entire fields of view that allow the operator of the camera to move to a specific region for closeup shots. One of these cameras can replace two VGA cameras, and they can be programmed to record in color during the day and automatically switch to IR night vision after dark. A single Ethernet cable works for both data and power.
The ease and lack of expense involved in putting up video cameras has led to their widespread use, including in schools, and on public transportation. With DVR surveillance systems in schools, there has been little controversy over their use to monitor the outside and immediate environs of school buildings. But there are parents, teachers, and students who are opposed to their use inside school buildings. Critics say that cameras inside schools don’t deter theft or other crimes, and that they could be used for “political” rather than surveillance reasons.
On public transport, DVR security cameras generally receive public support, but Japan has faced criticism of the placement of surveillance cameras in their “women only” cars on public trains to discourage “groping” incidents could have the unintended side effect of blaming victims. Specifically, the argument goes, if a woman rode in one of the other train cars either by choice or not, and if she were a victim of crime, would people contend that she was “asking for it” by not being in the surveillance cars?
The ethical implications of DVR surveillance systems will continue to be debated; there is little doubt that these systems will continue to be installed more frequently in more homes and businesses.