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TechTalks

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What is IP66?

Ans:
For load cell sealing techniques, Rice Lake Weighing Systems uses the Ingress Protection (IP) rating system. We find the IP numbers and their definitions are suitable for a classification of load cells and only apply IP numbers to such cells. The IP numbers on a load cell further specify the treatment a specific cell can endure in environments more severe than simple washdown. The following table defines the IP numbers.

Example: Protection level offered by an IP 67 rated protected product
6 = Totally protected from dust
7 = Protected from the effects of immersion between 15cm and 1m

First Number

Protection against solid objects

0

No protection

1

Protected from solid foreign objects of 50 mm and greater (e.g., accidental touch by hands)

2

Protected from solid objects of 12 mm and greater (e.g., fingers)

3

Protected from solid objects more than 2.5 mm (e.g., tools and small wires)

4

Protected from solid objects more than 1 mm (e.g., small wires)

5

Protected from dust; limited entrance (no harmful deposit)

6

Totally protected from dust


Second Number

Protection against liquids

0

No protection

1

Protected from vertically-falling drops of water (e.g., condensation)

2

Protected from direct sprays of water up to 15° from vertical

3

Protected from direct sprays of water up to 60° from vertical

4

Protected from water sprayed from all directions; limited entrance allowed

5

Protected from low pressure jets of water from all directions; limited entrance allowed

6

Protected from strong jets of water (e.g., for use on ship decks); limited entrance allowed

7

Protected from the effects of immersion between 15cm and 1m

8

Protected from extended periods of immersion under pressure

IP Numbers with Hermetically Sealed (HS) or Environmentally Protected (EP) Ratings
Rating Protection

EP

Dust proof, not protected from moisture or water

IP65

Dust proof, protected from splashes and low-pressure jets

IP66

Dust proof, protected from strong water jets

IP67

Dust proof, protected from temporary immersion in water 1 meter deep for 30 minutes

IP68

Dust proof, protected from continuous immersion in water under more severe conditions than IP67

IP66/68

Dust proof, protected from strong water jets and/or constant immersion

 
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What is image resolution?

Ans:
The term resolution is often used for a pixel count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field.An image of N pixels high by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as resolution, the convention is to describe the pixel resolution with the set of two positive integer numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as 7680 by 4320. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of megapixels, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as pixels per inch or per square inch. None of these pixel resolutions are true resolutions, but they are widely referred to as such; they serve as upper bounds on image resolution.

According to the same standards, the number of effective pixels that an image sensor or digital camera has is the count of elementary pixel sensors that contribute to the final image, as opposed to the number of total pixels, which includes unused or light-shielded pixels around the edges.

Reference: wikipedia

 
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What is Lux?

Ans:
Illuminance is a measure of how much luminous flux is spread over a given area. One can think of luminous flux (measured in lumens) as a measure of the total "amount" of visible light present, and the illuminance as a measure of the intensity of illumination on a surface. A given amount of light will illuminate a surface more dimly if it is spread over a larger area, so illuminance is inversely proportional to area.


Reference: wikipedia

 
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What is CMOS? What is CCD?

Ans:
Complementary metal–oxide–semiconductor (CMOS) (/
?si?m?s/) is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS technology is also used for several analog circuits such as image sensors (CMOS sensor), data converters, and highly integrated transceivers for many types of communication. Frank Wanlass patented CMOS in 1967 (US patent 3,356,858).

CMOS is also sometimes referred to as complementary-symmetry metal–oxide–semiconductor (or COS-MOS).The words "complementary-symmetry" refer to the fact that the typical digital design style with CMOS uses complementary and symmetrical pairs of p-type and n-type metal oxide semiconductor field effect transistors (MOSFETs) for logic functions.

Two important characteristics of CMOS devices are high noise immunity and low static power consumption. Since one transistor of the pair is always off, the series combination draws significant power only momentarily during switching between on and off states. Consequently, CMOS devices do not produce as much waste heat as other forms of logic, for example transistor-transistor logic (TTL) or NMOS logic, which normally have some standing current even when not changing state. CMOS also allows a high density of logic functions on a chip. It was primarily for this reason that CMOS became the most used technology to be implemented in VLSI chips.

The phrase "metal–oxide–semiconductor" is a reference to the physical structure of certain field-effect transistors, having a metal gate electrode placed on top of an oxide insulator, which in turn is on top of a semiconductor material. Aluminium was once used but now the material is polysilicon. Other metal gates have made a comeback with the advent of high-k dielectric materials in the CMOS process, as announced by IBM and Intel for the 45 nanometre node and beyond

Reference
: wikipedia

 
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What is Varifocal lens? What is Fixed focal?

Ans:
In film and photography, a prime lens is either a photographic lens whose focal length is fixed, as opposed to a zoom lens, or it is the primary lens in a combination lens system. Confusion can sometimes result due to the two meanings of the term if the context does not make the interpretation clear. Alternative terms primary focal length, fixed focal length, and FFL are sometimes used to avoid ambiguity

A varifocal lens is a camera lens with variable focal length in which focus changes as focal length (and magnification) changes, as compared to parfocal ("true") zoom lens, which remains in focus as the lens zooms (focal length and magnification change). Many so-called "zoom" lenses, particularly in the case of fixed lens cameras, are actually varifocal lenses.




Reference: wikipedia

 
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What is D1? What is TVL?

Ans:
360x240=>CIF
640x480=>VGA
720x480=>D1
1280x720=>HD(equvalent megapixel)
1920x1080=>Full HD(equvalent 2megapixel)

TVL, sometimes also referred to Lohr, refers to a TV line or horizontal resolution lines, technically speaking, TVL refers to the height of the picture of the human eye can recognize a vertical line, In other words, that is, in a width equal to the picturethe high region Mile, be able to tell the number of black and white lines, the the provisions aim is to make it not aspect ratio. TVL applied to the TV show, also applies to the the DVD machine-generated signal format. DVD 720 pixels (NTSC and PAL formats are) available 720 divided by 1.33 (aspect ratio 4:3) to obtain TVL 540.

Ratio of 1.78 (16:9) display, the TVL 405. In fact most DVD can only provide 500 TVL 540 TVL, Filtering and lower quality due to digital-to-analog converter.

DVD, that is, D1 resolution in NTSC, 480 TVL, PAL to 576 TVL.

The NTSC standard has 525 lines of scanning lines, but only about 480 to 483 rows are visible. PAL 625 scanning line, but only 576 to 580 of the line is visible. (Other lines are black, contains the sync pulses and other information).

All video format scanning line of the tree are the same, so the actual impact picture quality TVL decided.

 
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What is NTSC? What is PAL?

Ans:
NTSC, named for the National Television System Committee,[1] is the analog television system that is used in most of North America, parts of South America (except Brazil, Argentina, Uruguay, and French Guiana), Myanmar, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories (see map). Most countries using the NTSC standard, as well as those using other analog television standards, are switching to newer digital television standards, of which at least four different ones are in use around the world. North America, parts of Central America, and South Korea are adopting the ATSC standards, while other countries are adopting or have adopted other standards.

The first NTSC standard was developed in 1941 and had no provision for color television. In 1953 a second modified version of the NTSC standard was adopted, which allowed color television broadcasting compatible with the existing stock of black-and-white receivers. NTSC was the first widely adopted broadcast color system and remained dominant where it had been adopted until the first decade of the 21st century, when it was replaced with digital ATSC. After nearly 70 years of use, the vast majority of over-the-air NTSC transmissions in the United States were turned off on June 12, 2009 and August 31, 2011 in Canada and most other NTSC markets[citation needed]. Digital broadcasting permits higher-resolution television, but digital standard definition television in these countries continues to use the frame rate and number of lines of resolution established by the analog NTSC standard; systems using the NTSC framerate and resolution (such as DVDs) are still referred to informally as "NTSC". NTSC baseband video signals are also still often used in video playback (typically of recordings from existing libraries using existing equipment) and in CCTV and surveillance video systems.

PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system. The articles on broadcast television systems and analogue television further describe frame rates, image resolution and audio modulation. For discussion of the 625-line / 50 field (25 frame) per second television standard, see 576i.



Reference: wikipedia

 
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What is H.264?

Ans:
H.264/MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video. The final drafting work on the first version of the standard was completed in May 2003.

H.264/MPEG-4 AVC is a block-oriented motion-compensation-based codec standard developed by the ITU-T Video Coding Experts Group (VCEG) together with the International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) joint working group, the Moving Picture Experts Group (MPEG). The product of this partnership effort is known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 AVC standard (formally, ISO/IEC 14496-10 �V MPEG-4 Part 10, Advanced Video Coding) are jointly maintained so that they have identical technical content.

H.264 is perhaps best known as being one of the codec standards for Blu-ray Discs; all Blu-ray Disc players must be able to decode H.264. It is also widely used by streaming internet sources, such as videos from Vimeo, YouTube, and the iTunes Store, web software such as the Adobe Flash Player and Microsoft Silverlight, and also various HDTV broadcasts over terrestrial (ATSC, ISDB-T, DVB-T or DVB-T2), cable (DVB-C) and satellite (DVB-S and DVB-S2).


Reference: wikipedia

 
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What is AGC?

Ans:
Auto Gain Control.

 
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What is POC? What is POE?

Ans:
POC means PowerOnCable, POE means PowerOnEthernet.

 
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What is AWB?

Ans:
AWB means Auto White Balance.

 
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What is BLC?

Ans:
BLC means Back Light Control.

 
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What is AES?

Ans:
AES means Auto Electronic Shutter.

 
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What is WDR? What is HDR?

Ans:
High dynamic range imaging (HDRI or HDR) is a set of methods used in imaging and photography to allow a greater dynamic range between the lightest and darkest areas of an image than current standard digital imaging methods or photographic methods. HDR images can represent more accurately the range of intensity levels found in real scenes, from direct sunlight to faint starlight, and is often captured by way of a plurality of differently exposed pictures of the same subject matter.

In simpler terms, HDR is a range of methods to provide higher dynamic range from the imaging process. Non-HDR cameras take pictures at one exposure level with a limited contrast range. This results in the loss of detail in bright or dark areas of a picture, depending on whether the camera had a low or high exposure setting. HDR compensates for this loss of detail by taking multiple pictures at different exposure levels and intelligently stitching them together to produce a picture that is representative in both dark and bright areas.

HDR is also commonly used to refer to display of images derived from HDR imaging in a way that exaggerates contrast for artistic effect. The two main sources of HDR images are computer renderings and merging of multiple low-dynamic-range (LDR) or standard-dynamic-range (SDR) photographs. Tone mapping methods, which reduce overall contrast to facilitate display of HDR images on devices with lower dynamic range, can be applied to produce images with preserved or exaggerated local contrast for artistic effect.

example
Reference: wikipedia

 
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What is Privacy Zone?

Ans:
Just is privacy zone.

 
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What is S/N Ratio?

Ans:
S / N Ratio, also known as the signal to noise ratio. Indicate that how much is necessary signal and useless noise signal, expressed by decibels (dB, Decibel). Show the anti-interference ability of camera, and reaction in the picture quality is clean on the screen, noiseless and higher signal-to-noise ratio, says the less noise and signal the better.

 
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What is Infrared?

Ans:
Infrared (IR) light is electromagnetic radiation with longer wavelengths than those of visible light, extending from the nominal red edge of the visible spectrum at 0.74 micrometres (�gm) to 300 �gm. This range of wavelengths corresponds to a frequency range of approximately 1 to 400 THz,[1] and includes most of the thermal radiation emitted by objects near room temperature. Infrared light is emitted or absorbed by molecules when they change their rotational-vibrational movements. The existence of infrared radiation was first discovered in 1800 by astronomer William Herschel.

Much of the energy from the Sun arrives on Earth in the form of infrared radiation. Sunlight at zenith provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation.[2] The balance between absorbed and emitted infrared radiation has a critical effect on the Earth's climate.

Infrared light is used in industrial, scientific, and medical applications. Night-vision devices using infrared illumination allow people or animals to be observed without the observer being detected. In astronomy, imaging at infrared wavelengths allows observation of objects obscured by interstellar dust. Infrared imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatus.

Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectroscopy, and weather forecasting. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space, such as molecular clouds; detect objects such as planets, and to view highly red-shifted objects from the early days of the universe.

Humans at normal body temperature radiate chiefly at wavelengths around 10 �gm (micrometers), as shown by Wien's displacement law.

At the atomic level, infrared energy elicits vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states for molecules of the proper symmetry. Infrared spectroscopy examines absorption and transmission of photons in the infrared energy range, based on their frequency and intensity.



Reference: wikipedia


 
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What is ONVIF?

Ans:
ONVIF is an open industry forum for the development of a global standard for the interface of IP-based physical security products.

ONVIF is committed to the adoption of IP in the security market. The ONVIF specification will ensure interoperability between products regardless of manufacturer.

The cornerstones of ONVIF are:

  • Standardization of communication between IP-based physical security

  • Interoperability between IP-based physical security products regardless of manufacturer

  • Open to all companies and organizations

Reference: ONVIF

 
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What is PELCO?

Ans:
In the monitoring interface development in the field, we need to use some common agreement, and of PELCO the monitoring equipment on the market today have a very wide range of applications.The PELCO TCP, when supporting the use of its products, it can be compatible with each other.However, in some cases, due to the needs of the project, the requirements to control Pelco matrix with other equipment (such as a computer or RS485 joystick) or lens, which requires full understanding Pelco transmission protocol.

Used two protocols: PELCO-D agreements and PELCO-P protocol.
PELCO-D protocol parsing
PELCO-D protocol generally used for communication between the matrix and other equipment.Its format is as follows:

Byte 1

Byte 2

Byte 3

Byte 4

Byte 5

Byte 6

Byte 7

Synchronization word

Address code

Command Word 1

Command word

Data 1

Data 2

Checksum

All values ​​are expressed in hexadecimal.
Synchronization words are usually $ FF.
The address code matrix communication logical address of the device can be set in the device.
Command word and command word is set as follows:

 

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Command Word 1

Sence code

To 0

To 0

Automatic / manual scan

The camera is turned on / off

Aperture Close

Iris Open

Focus Near

Command word

Focal length zoom out

Perspective widens

Perspective narrows

On

Under

Left

Right

To 0

Sence code with Bit4 and Bit3.Bit4 and Bit3 1 Sence code is 1, the command is automatically scan and the camera is turned on; Sence code is 0, the command is manually scanned and camera Close.Of course, if Bit4 or Bit3 0, then that command is invalid.
Information 1 speed pan around the lens, the value from $ 00 (stop) to $ 3F (high-speed), in addition to a value is $ FF, said the highest speed.
Move up and down 2 shows lens speed value from $ 00 (stop) to $ 3F (high speed).
Checksum the number Byte2 to Byte6 and (if more than 255 divided by 256 and then take the remainder).
PELCO-P protocol analysis
PELCO-P protocol commonly used RS-485 transmission baud rate for 4800,1-bit start bit
And stop-bit, 8-bit data bits, no parity.The format is as follows:

 

Byte

Value

Function

1

$ A0

Start code

2

$ 00 to $ 1F

Address code

3

Data byte 1

Data bit 1

4

Data byte 2

Data bit 2

5

Data byte 3

Data bit 3

6

Data byte 4

Data bits

7

$ AF

Stop code

8

$ 00 - $ FF

Checksum

The start code is a fixed value $ A0.
The address of the code is the logical address of the device, set by DIP switches on the receiving device.
Data bits 1 to 4 meaning is as follows:

 

Bit number

7

6

5

4

3

2

1

0

Data bits
Element 1

0

The camera is turned on

Automatic scanning

The camera is turned on / off

Aperture Close

Iris Open

Focus Near

Focal length zoom out

Data bits
$ 1.2

0

Perspective widens

Perspective narrows

Under

On

Left

Right

0

Data bits
$ 3

 

Translational velocity of $ 00 (stop) to $ 3F (high-speed) and $ 40 (high speed)

Data bits
$ 4

 

Move up and down speed $ 00 (stop) to $ 3F (high speed)

The stop code is a fixed value $ AF.
Checksum number of Byte2 to Byte6 this exclusive-or the values ​​(XOR).
The address code braid address code $ 00 represents the first piece of equipment.
Some special commands PELCO-D and PELCO-P protocol, some advanced control equipment.

 
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Comparison of common video signal transmission

Ans:
The video baseband transmission:
the most traditional TV monitor transmission mode, 0 ~ 6MHz video baseband signal without any treatment, direct transmission of analog signals through coaxial cable (unbalanced).
Advantages: short-range transmission loss of video signal is small, low cost, stable system.
Disadvantages: short transmission distance of 300 meters or more high frequency attenuation greater, can not guarantee the quality of the image; need cloth one way video signal cable, Transmission Control the signal separately cloth cable; structure for the star-shaped structure, wiring capacity, maintenance difficulties, poor scalability, suitable for small systems.

Optical fiber transmission:
common with Analog Optical, VGA Optical, Digital Optical, solve dozens or even hundreds of kilometers of transmission of TV monitoring solution, through video and control signals into laser signals in optical fibers.
Advantages: long transmission distance, low attenuation, anti-jamming performance, suitable for long distance transmission.
Disadvantages: not economic for the monitor signal transmission within a few kilometers; light welding and maintenance needs of professional and technical personnel and equipment operation processing, maintenance, technical requirements, and not easy to upgrade expansion.

Network traffic:
solve Metro between distant point is extremely decentralized control transmission of MPEG2 / 4, H.264 audio and video compression format transmission monitoring signal.
Advantages: network video server as the monitoring signal Upload equipment, as long as the Internet network, installed on the remote monitoring software can monitor and control.
Disadvantages: limited by the network bandwidth and speed, the current ADSL can only transfer small screen, low-quality images; several dozen frames per second can only transfer images, animation is very clear and there is a delay, can not do real-time monitoring.

Microwave transmission:
it is one of a few kilometers or even tens of kilometers is not easy wiring solution for workplace monitoring transmission.FM modulation or AM modulation approach, equipped with the image on the high-frequency carrier converted to high-frequency electromagnetic waves transmitted in the air.
Advantages: integrated, low cost, more stable performance, eliminating the need for wiring and cable maintenance costs; dynamic real-time transmission of broadcast-level image, good resolution image transfer, and completely instant; networking flexibility, scalability, plug and play ; maintenance costs low.
Disadvantages: As a result of the microwave transmission bands above 1GHz, commonly used in the L-band (1.0 to 2.0GHz), S-band (2.0 ~ 3.0GHz), Ku-band (10 ~ 12GHz), the transmission environment is an open space, if use of large cities, radio waves are more complex, relatively vulnerable to external electromagnetic interference; microwave signal transmission line, not a mountain, building block; if there is an obstacle, plus the relay to be addressed, Ku-band affected by the weather more serious especially in rain and snow will be more serious rain attenuation phenomenon.But now digital microwave video transmission products, anti-interference ability and scalability are improved greatly.

Twisted pair transmission (balance transfer):
video baseband transmission a 75Ω unbalanced mode conversion as the balanced mode transmission.Solve the surveillance video within 1 km of transmission, electromagnetic environment is relatively complex, the occasion better solution, will be monitoring the transmission of video signal processing by balancing symmetrical manner.
Advantages: Easy wiring, low-cost, anti-common-mode dry worries performance.VGA twisted pair transmitter.
Disadvantages: can only solve the surveillance video transmission in less than one kilometer, and a twisted-pair can only transmit one image, not suitable for application in the large and medium-sized monitor; twisted pair fragile and anti-aging ability is poor, not suitable for field transmission; twisted pair transmit high frequency attenuation greater image color will be a great loss.

Broadband cable transmission:
the video amplitude modulation, audio FM equipped FSK data signal modulation technology integrated into the two-way transmission of a coaxial cable in dozens of road surveillance video, sound, control and alarm signal.
Advantages: full use of the coaxial cable of the resource space, the two-way transmission of 30-way audio and video, and control signals in the same cable, the "Link"; simple construction, easy maintenance, and substantial savings in the cost of materials and construction costs; frequency division multiplexing dispersed solve teleportation point wiring is difficult to monitor the transmission problems; RF transmission the way attenuation carrier signal, image signal attenuation is relatively small, brightness, chroma transmission synchronization nested, to ensure that the image quality is about 4; unbalanced 75Ω coaxial way transmission so that it has a strong anti-interference ability, complex electromagnetic environment occasions able to ensure the quality of the image.
Disadvantages: weak signal transmission system debugging technology requirements, must use professional equipment trunk line is a piece of equipment problems, may cause the entire system to not image other broadband modulation end external AC110V AC power supply (but mostly monitoring AC110V AC power supply points have this condition).

 

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