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: ...
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...
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...
