VIDEO SURVEILLANCE

information portal for CCTV video surveillance systems (CCTV)

CCTV

a collection of video cameras for video surveillance is used.

CCTV differs from the TV that all devices are closed directly with a cable or wireless transmitter, which can not be received by standard TV antenna or transmission equipment.The video signals can be connected are determined by the device on an Internet dedicated.

CCTV is generally used in areas where there is an increased need for security, such as banks, airports and city centers. CCTV was originally designed as a means to increase security designed for banks, but over time it became a viable way of general video surveillance and homeland security

A basic CCTV system consists of the following: Camera, lens and power supply. Recorder, a VCR or DVR. One monitor. Wiring

cameras

CCTV cameras are changing in color or monochrome cameras, the ability of color and black and white to (day / night video surveillance cameras). Surveillance cameras, which are between color and monochrome switch for low-light conditions measured at various time points. There are two reasons for using a surveillance camera that can switch between color and monochrome switches, monochrome CCTV cameras much more sensitive to low light, and color cameras can be used with infrared lighting. If there is sufficient light is available, there is the advantage of using a color surveillance camera color, such as record such as the color of a car or clothing of a person.

The main function of a surveillance camera is to light to convert a video signal, need all the surveillance cameras, a lens, light, focus on an image sensor is located directly behind the lens “within the closed circuit camera.

There are two types of image sensor is available, a CCTV camera with a CMOS (Complementary Metal-Oxide Semiconductor) image sensor and the other most common way that a CCD used (Charge Coupled Device) image sensor chip. The majority of CCTV cameras and Camcorders with a CCD image sensor, while CMOS sensors with frequent webcams, camera home surveillance cameras and digital photography budget to be used. CCD cameras are able to create an image resolution is much clearer and much more.

All

CCTV cameras require power, it is usually 12 volts DC, 24 V AC or 240 volts AC.

CCTV targets

As in the section on video surveillance cameras mentioned, require all cameras, an optical lens. The work of the lens to limit and focus is light onto the image sensor of the camera closed circuit. A target can also automatically control the amount of light reaching the image sensor, called these lenses Auto Iris (AI) and the lenses are usually used outdoors when the light changes constantly throughout the day, night and in varying weather conditions.

There is also the work of the lens to control the depth of the image, whether for a wide-angle or closed-angle image of the distance of the object in question from the based surveillance camera. If mobile cameras are used a zoom is to enable normally installed on to different points of the monitored area, are considered. zoom lenses are controlled usually by the operator of CCTV.

CCTV Recording Devices

The recording device receives and stores images of the closed circuit camera in front of elapsed time recorder and video multiplexers are typically used in systems CCTV, but due to the changing technology of digital video recorders are now used more often.

Time on the video recorder can shoot the surveillance camera for different periods in a single 3-band one-hour video, of lengths recorded from 3 hours to more than 960 hours. The problem with video recorder, elapsed time is that the more they are used to record information if it can record video per second, similar to taking a picture of 25 per second for a picture every 4 seconds for example.

digital recorders use hard drives for storing recorded information and can much longer save, depending on the size of the disk and the codec used. DVR combined and improved the recording capabilities of a time-recorder and a multiplexer.

CCTV and video surveillance Switcher

If there is a demand the recording of a closed circuit camera and video switch can be used, the cameras are connected to the switch and the switch will automatically switch the image on the screen and video feed. The disadvantage of using a switch that when an incident it is possible that change the image of the closed circuit camera so that the incident will be missed.

CCTV and video surveillance multiplexer video

A multiplexer a device that takes multiple video images and a VHS tape, it uses the properties of the PAL signal, as many save images from multiple video cameras at every second as possible. The information about the recorded video is by the amount of CCTV cameras on the system and the length of time the is a video recorder is set to record limited.

standalone CCTV digital video recorder

A stand-alone DVR designed specifically for CCTV systems. It uses hard drives video information and an embedded operating system for controlling the functions of recorder, this type of recording device will store most often used with existing CCTV systems. CCTV digital video recorders have different settings so that more image information on both needs with technologies such as video motion detection is recorded, it means that the camera recorded images of closed circuit television only when information changes the picture, eg a person walking in front of the camera.

P

Many DVRs to a network or modem can be connected to allow remote access.

CCTV DVR comes with a high contrast LCD is Media DVR.

PC DVR work based much in the way CCTV DVR, but the use of video capture cards and software to carry out additional operations of the DVR, these types of DVR can be upgraded easily to additional cameras by going to put more capture cards. As with the standalone DVR, can PC recorders are connected to the recorder and to the Internet for remote access.

CCTV Network Video Server

Network Video Server for CCTV cameras, IP WAN or LAN computer networks, where each camera has determined its own unique IP address.

CCTV Monitors

CRT monitors are generally designed for systems closed circuit television and are equipped with a composite video input BNC (Bayonet Nut Coupling) taken. CCTV monitors are also available for long-term use of standard TVs interpreted in comparison and provide for higher screen resolutions.

in the late 1940s, developed as a miniature version of the C-type connector, Bayonet Neil-Concelman (sometimes mistaken as a male British Naval Connector or Bayonet Nut). A connector widely used in the television industry closed circuit, usually install coaxial cable to. Simple and reliable with little video signal loss. A rotating ring outside the tube, the cable locks into a socket.

CCTV lighting

Brightness levels need all the cameras to be able to select an image, color cameras generally work well in darker environments, the cameras CCTV color. Infrared light can also be used with monochrome CCTV cameras.

There are different types or infrared emitters available, standard bulbs or LED (Light Emitting Diode) type.

infrared lighting to illuminate areas with different frequencies, although to the naked eye, CCTV cameras, the light emitted . After the frequency range of the infrared light on how visible the light of the lamp with the naked eye depends. However, note that not all cameras sensitive enough to pick up all the frequencies of the infrared.

Covert CCTV

Covert CCTV is the practice of using video cameras in places that are not evident, under supervision in the camera coverage targeted surveillance, but it is recommended that there are reasonable grounds for the purposes of covert surveillance and that their main objectives are clearly stated, are only used for the prevention of crime and not use longer than expected.

Remote CCTV

Remote CCTV, with access to CCTV images on a computer network or standard telephone networks. The software is on the local PC, the access to digital video recorder

CCTV Camera IP

CCTV IP Internet Protocol as CCTV has used. Traditional CCTV systems use digital cameras or analog with analog cables that connect to a recording device like a DVR. IP video cameras are designed to perform in any computer existing TCP wired or wireless / IP network or directly via a broadband connection, so that the surveillance camera can be accessed from any computer connected to the network, even over the Internet.

computers on the network used to store the images from surveillance cameras, but with the flexibility of IP video surveillance, video Surveillance cameras on opposite sides of the world are located. can during IP video cameras are connected directly to an existing network, the bandwidth is always a consideration that the data sent from the surveillance camera probably much larger than the data over standard networks transmit, the normal business hours, if not correctly, the entire network is developing slowly.

CCTV video signal

The video signal as the information signal to the generated moving image from a video camera is known, use We have a standard signal video called PAL (Phase Alternate Line) is a color or monochrome video signal, consisting of 25 pictures or frames per second. A new generation of cameras, called IP-CCTV cameras Internet Protocol (CCTV) uses a data signal that contains a series of computer-readable images. These CCTV cameras are usually connected directly to a computer or computer network and to allow access to the software to live display, recording and playback of video images. A format for these fast motion video is MPEG (Moving Pictures Experts Group) called.

CCTV video transmission

Video Streaming is the way to the video signal from the camera to the Record or get tracking device. It can be transmitted by cable or by radio.

The cable most often used for the transfer is RG6 connected coaxial cable.

network cable is often used as the video is able to travel further, than the coaxial cable, twisted-pair standard.

CCTV resolution

Resolution refers to the production of the number of defined parts of the image by a horizontal camera monitor, recorded by video or digital video recorder and on.

see CCTV manufacturer that TVL (TV lines). A minimum of 420 TVL is recommended.

The information TVL PAL analog video is closely related to the pixels of a digital image.

VHS (video home system) recorder to record 300 lines of a monochrome image, or 240 lines, a color image, SVHS ( Super Video Home System) is capable of recording 400 lines monochrome image and 340 rows of a color image.

In Digital Video Recorder (DVR) have the advantage of the situation, the PAL analog signal converted into a digital signal at different resolutions, the disadvantage is that the higher the resolution of the recorded image, the greater is the file of this digital image. The transition from analogue PAL signal from a digital image with a codec (compressor-decompressor).

CCTV codec

A codec is used that convert an analog video signal into a digital video signal, either with hardware or software. Codec play an important role in digital video recorders, they are not only used to convert the analog signal into a digital signal but also information produce the best video quality for small file size. It makes a big difference in the amount of videos that can be stored on a hard drive DVR.

There are many standards CODEC used for video compression, which can occur are MPEG-2, MPEG -4, JPEG 2000, AVI and H.264, H.264 video codec is the final course introduction of video surveillance in the market, arising from video-conferencing.


CCTV lens