What is a DVR (digital video recorder)?
DVR (digital video recorder) records by hard disk skill which is different with analog video skill of traditional recorder, so it is called Digital Video Recorder or Disk Video Recorder. DVR divides as three kind...
DVR card is a kind of kit on circuit wafer, which includes soft compression and hard compression. Soft compression card makes some capture chips as the core, cooperating with periphery kits to achieve video captu...
What is a Fiber Optic Video Converter?
Fiber optic video converter which assists wired transmission is a kind of equipment converting signals mode between optical and electronic. Fiber optic video converter involves analog type and digital type: Analo...
CCD (Charge Coupled Device) is made by semiconductor material of super photosensitivity. CCD can convert luminous flux into electron, and then electric signal is converted into digital signal. Finally, digital sig...
In CCTV system, bracket is applied for supporting camera and pan tilt. If camera only monitors some fixed place, common bracket is competent enough. Simple installation, low price and various kinds are the advant...
What is a Low Illumination Camera?
Low illumination camera which can work in weak light condition is a kind of CCTV camera, involving moon type, star type and IR type. Such high sensitivity cameras as moon grade and star grade can normal work in ti...
CCD (charge couple device) is a semiconductor-made kit, so it shows up high sensitivity, anti highlight, small distortion, mini bulk, long expectancy, anti shake etc. CCD camera involves the below kinds: D...
CCD (charge couple device) is a semiconductor-made kit, so it shows up high sensitivity, anti highlight, small distortion, mini bulk, long expectancy, anti shake etc. CCD camera involves the below kinds: D...
Aperture which is a kind of optical iris is inside of lens and adjustable. Aperture can control luminous flux of crossing lens. Aperture involves manual aperture and auto aperture: (1) Manual aperture: ...
Housing is the important component in CCTV system. It ensure camera normally work under poor conditions like dusty, rainy and temperature of high or low. There are two kinds of housings. The one is indoor housin...
Lens is a kind of optical clarity kit made by one or more optical glasses spherical. It is applied for focalizing or scattering light from targets, so as to form real image or virtual image. There are many kinds o...
Zoom camera is an optical system that the position of focal surface is fixed but focal length adjustable. Zooming is finished by moving glass-chip inside of lens as to change glass-chip positions. By such way, it ...
Monitor is the standard device of video out, which is essential for us to browse image from camera. Monitors can be color or B/W(black/white), and dimensions can be 9”、10”、12”、14”、15”、17” and 21” ,but ...
In the multi-camera surveillance system, it is usually found that multiple pictures show on one monitor together. When adopted, multiplexers can make monitors which are as the same as multiplexers in number, displ...
In the multi-camera surveillance system, it is usually found that multiple pictures show on one monitor together. When adopted, quads processors can make monitors which are as the same as quads processors in numbe...
During CCTV system, the quantity proportion between camera and monitor ranges from 2:1 to 5:1. In order to make fewer monitors support more cameras, it is necessary for video switcher to distribute some channel si...
We often hear of pan tilt, but most people are unfamiliar to it. Actually, pan tilt is an installing plat composed by two motors which can pan or tilt moving. Pan tilt a supporting device used to install and fix c...
What is an Object Tracking Speed Dome?
Auto-object-tracking-speed-dome integrates features of optics, electronics, mechanism, information processing and network. It is composed by lens, dynamic actuator, movement controller as well as sync speed parts ...
What is Access Control System?
Access control system is a new management pattern for entrance, that is to say this system allows authorized user but refuses unauthorized person to enter some certain interface. As son as received data, the contr...
As transmitter is synchronizing with receiver, signal synchronization must be done. HSYNC (horizontal sync) signal controls horizontal scanning and VSYNC (vertical sync) controls vertical scanning. Sync system in...
Embedded system means operating system integrates with software into hardware system of PC. Simply speaking, that is software integrates with hardware, which is similar to the work pattern of BIOS. Embedded system...
In the intelligent buildings, information and procession is a very heavy task. So managements are usually finished by PC system. In other words, user programs in software to achieve keyboard controlling of pan til...
This kind of detector usually adopts Bi-directional Pulse Notation pattern, that is to say alarm happens in coming direction but doesn’t happen in going direction. The detector can recognize invade direction...
Super Hole Accumulation Diode (HAD) is embedded in CCD senor. So it is helpful to enhance detecting ability and signal processing ability, even can decrease noise and interference as recording. In this way, image ...
In long distance transmission, it is necessary for well transmitting to adopt thick cable as well as video amplifier in order to strengthen signal. Video amplifier can strengthen brightness, chromaticity and sync ...
Video distributor which is adopted to distribute channel signals is often found in video transmitting process. It serves as distributing one channel into multiple channels. The common found distributors are 2 way ...
Video server is a dedicated PC device which serves AV (audio& video) of compressing, storing and processing. Video server is widely applied for video surveillance, network education, video conference, spot announc...
What is Communication Interface?
In CCTV system, communicating interface is mainly applied in AV (audio& video) input-output process. So there are these kinds: ○1RS-232, RS-485 and general interface of network, ○2USB2.0 interface of supporting ...
Focal length is a parameter for all optic devices. Speaking by optics theory, focal length means the distance from focus point to lens centre. Focal length is significant for camera lens. Focal length and image si...
As a unit of brightness, illumination means camera’s requirement for brightness of surrounding area. The unit of illumination is Lux. 1Lux nearly equals to illumination of 1m distance of 1 candle. The &ldquo...
Lux is one of the ISI (international system of units). The using of Lux involves one length unit----meter. 1Lux =1 lumen/ m2.
Camera used CCD format can be 2/3", 1/2", 1/3" or others. Image size becomes smaller; accordingly pixel quantity and sensitivity become less. But fortunately this problem has been solved. It is savi...
Signal-to-Noise Ratio is a main parameter of camera. SNR=signal/noise×20log. Most cameras show the SNR specific-value when AGC shuts. Showing this specific-value is in order to avoid noise PWL (power level) risin...
Resolution is an important parameter to evaluate cameras. It means that when a camera shoots the bars spaced at equal interval between black and white, the most number of lines could be seen on the screen of monit...
Minimum illumination means photosensitivity of CCD or minimum light ray needed by CCD. The illumination unit is Lux. The smaller the number, the less light ray needs for camera, and the more sensible the lens will...
Full duplex is defined as sending and receiving synchronic. Full duplex demands: there are specific channels for sending and receiving. Full duplex is applied in star-network and ring-network, even applied to real...
Half duplex is defined as sending and receiving asynchronous, that is to say first sending or first receiving. Half duplex demands: sending and receiving can use same channel. It is applied in topology and local-a...
For object color changes along with luminance, there are different color-temperatures of images coming from different illumination conditions. For instance, tungsten lamp illumination makes image turn yellowing. G...
Pixel is the essential parameter for measuring quality of lens. Some packs appear 0.3million or 0.35million. Although the more pixels, the better quality image will be, but not to say the more pixels, the better. ...
VBR (Variable Bit Rate) means that CODEC (coder-decoder) can auto adjust bandwidth according to data quantity. In other words, when frames change fast and have multi colors, occupation of bandwidth will be larger;...
WDR (wide dynamic range) means a kind skill of ensuring camera recognize specific features of objects in strongly contrast. WDR camera is scores of times as dynamic range as traditional camera which has only 3:1 d...
What is depth of field? As some object has clear focal image, there is certain long distant can also be clearly focalized. The distance ranges from front of focal object to back of focal object. This distance is s...
AVS is an ENDEC (encoder & decoder) standard of AV (audio & video). AVS standard is created by China. AVS workgroup founded in June of 2002 and held first meeting in August of same year. After 7 normal meetings an...
Real-time Encoding and Decoding System
Real-time Encoding and Decoding System refers to that camera can real-timely process data, convert into normal MPEG－1or MPEG－2 image, finally store images to HD (hard disk). During this process, data will not be...
The accumulating time of electronics of camera can controls exposure time according to the changeability of electronics. This function is called electronic shutter. Electronic shutter function makes camera can cap...
Backlight compensation can get ideal exposure of object which is in front of the strong luminance background, no matter object moving to center, top, bottom, left, right or any other position of screen. For a comm...
The whole image is divided into multiple areas. Users can choose any one of these areas; even can set sensitivity of chosen area with 1-20 grades. Thus when objects are moving, they can be detected and recorded by...
Automatic gain control (AGC) is a kind of method for ensuring out-video meet demand of TV transmission provision. Automatic gain control (AGC) controls gain by detecting average PWL (power level) of video signal. ...
AVI (audio video interleave) is the video format of Windows3.1. Its features include good compatibility, easy adjustment, super image, huge bulk.
Content scrambling system is a digital encryption proposal for DVD video. DVD players which are permitted only by CSS can decode video data. Content scrambling system (CSS) is a very effective encryption method, s...
Div X refers to digital video CODEC (encoder & decoder) which is based on MPEG-4 skill. Div X format can compress big file into so small file as to can be transmitted on the Internet, thus meeting actual demands o...
Cameras design and procurement guide
This Guide can help monitor the implementation of projects. According to all solutions based on the parameters of cameras, the application environment and the place, it will help you to choose the best cameras, to...
Fps (frame per second) detection is applied for storing and showing signal quantity of dynamic video. Fps is also a film word or digital video word. As we know, single frame is motionless picture, but continuous d...
MPEG image encoding includes three factors: I frame, P frame, B frame. During MPEG encoding process, some images are compressed to I frame, some compressed to P frame, and rest compressed to B frame. I frame compr...
NTSC / NTSCNTSC (National Television Systems Committee NTSC) is a kind of video standard. NTSC is adopted in America, Canada, Japan, and some middle-south America countries for commercial TV broadcast. NTSC format...
PAL (Phase Alteration Line) is I adopted in most Europe countries, Australia and some middle-south America countries for commercial TV broadcast. PAL format speed is 25fps (25 Hz) and resolution is 625 lines (hori...
MPEG-4 has much difference with MPEG-1 or MPEG-2. As a compression algorithm, MPEG-4 is also a international standard that meets demands of integration and compression skills such as digital television, interactiv...
CMOS (Complementary Metal-Oxide Semiconductor) is the sensitimeter of camera. The manufacture skill of CMOS is similar to common chips. They are both semiconductors made by silicon and germanium. CMOS stores negat...
The PC-based DVR is recording equipment combined into a PC. It carries all the features of a PC as well as additional features of a DVR. With many models in the market, here’s how you can select a PC-based D...
DVR Introduction digital video recorder Digital Video Recording (DVR) Features DVRs you will have the ability to: A (DVR) is basically just a computer hard drive that is encased in a box that is made to look like...
In most surveillance operations using a DVR, the commonly used method is to link the DVR card to a computer containing the software. This has serious limitations in the event of a virus attack or power failure, be...
How Different is between C-Mount Lens and CS-Mount Lens?
Lens can be divided into C-Mount Lens and CS-Mount Lens. C-Mount Lens The flange back (distance from the surface where the lens comes in contact with the camera to the focal point) of C-Mount lens is 17.526mm (0...
Digital cameras have become extremely common as the prices have come down. One of the drivers behind the falling prices has been the introduction of CMOS image sensors. CMOS sensors are much less expensive to manu...
CCTV Security Camera Information for Non-Technical People
Get a good face shot Use Higher quality cameras at entry areas Doors, gates and other entry areas need a good quality, high resolution camera to record a good 'face shot.' The video from this camera should be con...
How Does the Cameras Auto Focus?
When the camera focused properly, the details of the image became clear; Images of the lines or the contours of objects become sharp. When the camera focused very clearly, the details of the image becomes clear. ...
How to Install and Adjust the CCTV Cameras?
The use of cameras is very easy, before it works, we should install the lens correctly, adjusting lens aperture, focus, and back focus, connect the signal cable and put through the power resource. But in the rea...
The camera is the core in the whole monitoring system. You can choose them according to the modes and locations of installation, environmental lights, image clarity or other specifications. The camera is the core...
According to the types of lens, lens can be divided into such kinds as the wide-angle lenses, the standard lenses, telephoto lenses, the zoom lens and the pinhole lenses. According to the size of objects, the rel...
Image Sensor Market Review and Forecast
A Rising Tide Raises Both CCD and CMOS Image Sensor Markets The battle between CCD and CMOS image sensors is cooling down, as each technology grows with their respective applications. While CMOS sensors have been...
The Classification of CCD Cameras and Surveillance Cameras
In the security surveillance system, the image is made by mainly CCD cameras. CCD can convert the light into electrons and storage or transfer them, the electrons also can be taken out to make the change of the vo...
The Difference between CCD and CMOS
1970 is a landmark year for image processing industry; the United States Bell Labs invented the CCD. After 20 years, people use it to create the digital cameras; image-processing industries are pushed into a new f...
If the camera is a human eye, the lens can be compared to eyeball; it is directly related to overseeing the proximity, scope and effectiveness of objects. The selection should be considered the following points: ...
The PARAM: AGC ON/OFF, ATW ON/OFF, ALC/ELC, BLC ON/OFF, LL/INT, VIDEO/DC, SOFT/SHARP, FLICKERLESS The cameras are used to take the pictures of the monitoring areas and convert them into the signal, according to t...
Specification Introduction of Zoom-Camera Technology
Zoom camera means cameras and lens are combined into one body, it is convenient to control the camera (multiples, focusing, and iris), indicator: resolution, optical zoom, the minimum illumination, etc. 1. Resol...
CCD Camera Functions and Performance Indicators
CCD camera common functions and the major performance indicators include: the resolution, the lowest light, the signal-to-noise ratio, AGC, back light compensation, electronic shutter, White balance, and synchrono...
The Selection of Platform (Pan / Tilt)
The platform can simply be understood as an all-round (horizontal 360 °, 90 ° vertical) base with free rotation. The platform expands the vision of camera. In television monitoring system, the places needi...
What to Know before You Choose Surveillance System
In this age of heightened awareness of security needs, video surveillance systems offer extra pairs of eyes to help you mange your business more carefully. Before starting to compare surveillance systems or evalu...
