mms be (final year)

7/29/2019 MMS BE (final year)

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DISPLAY SYSTEM

A display device, also known as an information display is a device for visualor tactile presentation of images (including text) acquired, stored, ortransmitted in various forms. While most common displays are designed topresent information dynamically in a visual medium, tactile displays, usually

intended for the blind or visually impaired, use mechanical parts todynamically update a tactile image (usually of text) so that the image maybe felt by the fingers. Here are the common types of display devices:

Analog electronic displays

CRT

CRTs, or video monitors, are the most common outputdevice on computers today. A CRT is an evacuatedglass tube, with a heating element on one end and a

phosphor coated screen on the other.

When a current flows through this heating element,called a filament, the conductivity of the metal filamentis reduced due to the high temperature. This causeelectrons to pile up on the filament, because they cannot move as fast as they would like to. Some of theseelectrons actually boil off of the filament.

These free electrons are attracted to a strong positive charge from the outer

surface of the focusing anode cylinder (sometimes called an electrostaticlens). However, the inside of the cylinder has a weaker negative charge.Thus when the electrons head toward the anode they are forced into a beamand accelerated by the repulsion of the inner cylinder walls in just the waythat water is speeds up when its flow though a smaller diameter pipe. By thetime the electrons get out they're going so fast that they fly past thecathode they were heading for.

The next thing that the electrons run into are two sets of weakly chargeddeflection plates. These plates have opposite charges, one positive the othernegative. While their charge is not strong enough to capture the fast moving

electrons they do influence the path of the beam. The first set displaces thebeam up and down, and the second displaces the beam left and right. Theelectrons are sent flying out of the neck of the bottle, until they smash intothe phosphor coating on the other end of the bottle.

The impact of this collision on the out valence bands of the phosphorcompounds knocks some of the electrons to jump into the another band.This causes a few photons to be generated, and results in our seeing a spoton the CRT's face.

Digital electronic displays

LCD


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A liquid crystal display (commonly abbreviated LCD) is a thin, flat displaydevice made up of any number of color or monochrome pixels arrayed infront of a light source or reflector. It is prized by engineers because it usesvery small amounts of electric power, and is therefore suitable for use inbattery-powered electronic devices.

Currently, its the most popular alternative to the CRT. LCDs are organicmolecules that, in the absence of external forces, tend to align themselvesin crystalline structures. But, when an external force is applied they will

rearrange themselves as if they were a liquid. Some liquid crystals respond

to heat (i.e. mood rings), others respond to electromagnetic forces.

When used as optical (light) modulators LCDs change polarization ratherthan transparency (at least this is true for the most popular type of LCDcalled Super-twisted Nematic Liquid crystals). In their unexcited orcrystalline state the LCDs rotate the polarization of light by 90 degrees. Inthe presence of an electric field, LCDs the small electrostatic charges of themolecules align with the impinging E field.The LCD's transition between crystalline and liquid states is a slow process.This has both good and bad side effects. LCDs, like phosphors, remain "on"for some time after the E field is applied. Thus the image is persistent like a

CRT's, but this lasts just until the crystals can realign themselves, thus theymust be constantly refreshed, again, like a CRT.

TFT LCD

TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is avariant of Liquid Crystal Display (LCD) which uses Thin-Film Transistor (TFT) technology to improve imagequality. TFT LCD is one type of active matrix LCD, thoughit is usually synonymous with LCD. It is used in both flatpanel displays and projectors.

In a TFT screen, also known as active matrix, an extramatrix of transistors is connected to the LCD panel - onetransistor for each colour (RGB) of each pixel. These transistors drive the


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pixels, eliminating at a stroke the problems of ghosting and slow responsespeed that afflict non-TFT LCDs.The liquid crystal elements of each pixel are arranged so that in their normalstate (with no voltage applied) the light coming through the passive filter is'incorrectly' polarised and thus blocked. But when a voltage is applied acrossthe liquid crystal elements they twist by up to ninety degrees in proportionto the voltage, changing their polarisation and letting more light through.The transistors control the degree of twist and hence the intensity of thered, green and blue elements of each pixel forming the image on thedisplay.

Vacuum fluorescent display

A vacuum fluorescent display (VFD) is a display device used commonly onconsumer-electronics equipment such as video cassette recorders, car

radios, and microwave ovens. Invented in Japan in 1967, the displaysbecame common on calculators and other consumer electronics devices. [1]

Unlike liquid crystal displays, a VFD emits a very bright light with highcontrast and can support display elements of various colours. VFDs candisplay seven-segment numerals, multi-segment alpha-numeric charactersor can be made in a dot-matrix to display different alphanumeric charactersand symbols. In practice, there is no limit to the shape of the image that canbe displayed - it depends solely on the shape of phosphor on the anode(s).Hundreds of millions of units are made each year. [2]

The device consists of a hot cathode (filaments), anodes (phosphor) andgrids encased in a glass envelope under a high vacuum condition. Thecathode is made up of fine tungstenwires, coated by alkaline earth metaloxides, which emit electrons when heated by an electric current. Theseelectrons are controlled and diffused by the grids, which are made up of thinmetal. If electrons impinge on the phosphor-coated plates, they fluoresce,emitting light. Unlike the orange-glowing cathodes of traditional vacuumtubes, VFD cathodes are efficient emitters at much cooler temperatures, andare therefore essentially invisible

he extra indicators (in our example, "VCR", "Hi-Fi", "STEREO", "SAP", etc.)are arranged as if they were segments of an additional digit or two or extra

segments of existing digits and are scanned using the same multiplexedstrategy as the real digits. Some of these extra indicators may use aphosphor that produces a different colour of light, for example, orange.
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The light produced by most VFDs contains many colours and can often befiltered to enhance the colour saturation providing a deep green or deepblue, depending on the whims of the product's designers. Phosphors used inVFDs are different from those in cathode-ray displays since they mustproduce acceptable brightness with only around 50 volts of electron energy,compared to several thousand volts in a CRT
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Plasma displayA plasma display panel (PDP) is a type offlat panel display common to large

TV displays (80 cm or larger). Many tiny cells between just two panels of

glass hold a mixture ofnoble gases. The gas in the cells is electrically turnedinto a plasma which emits ultraviolet light which then excitesphosphors to

emit visible light. Plasma displays should not be confused with LCDs,

another lightweight flatscreen display using different technology.

How plasma displays work

Composition of plasma display panel

The xenon, neon, and helium gas in a plasma television is contained inhundreds of thousands of tiny cells positioned between two plates of glass.Long electrodes are also put together between the glass plates, in front ofand behind the cells. The address electrodes sit behind the cells, along therear glass plate. The transparent display electrodes, which are surrounded

by an insulating dielectric material and covered by a magnesium oxideprotective layer, are mounted in front of the cell, along the front glass plate.Control circuitry charges the electrodes that cross paths at a cell, creating avoltage difference between front and back and causing the gas to ionize andform a plasma. As the gas ions rush to the electrodes and collide, photonsare emitted.[21][22]

In a monochrome plasma panel, the ionizing state can be maintained byapplying a low-level voltage between all the horizontal and verticalelectrodeseven after the ionizing voltage is removed. To erase a cell allvoltage is removed from a pair of electrodes. This type of panel has inherent

memory and does not use phosphors. A small amount of nitrogen is addedto the neon to increase hysteresis.
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In color panels, the back of each cell is coated with a phosphor. Theultraviolet photons emitted by the plasma excite these phosphors to give offcolored light. The operation of each cell is thus comparable to that of afluorescent lamp.

Every pixel is made up of three separate subpixel cells, each with differentcolored phosphors. One subpixel has a red light phosphor, one subpixel hasa green light phosphor and one subpixel has a blue light phosphor. Thesecolors blend together to create the overall color of the pixel, the same as atriad of a shadow mask CRT or color LCD. Plasma panels use pulse-widthmodulation to control brightness: by varying the pulses of current flowingthrough the different cells thousands of times per second, the controlsystem can increase or decrease the intensity of each subpixel color tocreate billions of different combinations of red, green and blue. In this way,the control system can produce most of the visible colors. Plasma displaysuse the same phosphors as CRTs, which accounts for the extremely accuratecolor reproduction when viewing television or computer video images (which

use an RGB color system designed for CRT display technology).

Digital Light Processing

Digital Light Processing (DLP) is a trademark owned byTexas Instruments,

representing a technology used in some TVs and video projectors. It was

originally developed in 1987 by Dr. Larry Hornbeck of Texas Instruments.

Digital micromirror device

In DLP projectors, the image is created by microscopically small mirrors laidout in a matrix on a semiconductor chip, known as a Digital MicromirrorDevice (DMD). Each mirror represents one or more pixels in the projectedimage. The number of mirrors corresponds to the resolution of the projectedimage (often half as many mirrors as the advertised resolution due towobulation). 800x600, 1024x768, 1280x720, and 1920x1080 (HDTV)matrices are some common DMD sizes. These mirrors can be repositionedrapidly to reflect light either through the lens or on to a heat sink (called alight dump in Barco terminology).

Rapidly toggling the mirror between these two orientations (essentially onand off) produces grayscales, controlled by the ratio of on-time to off-time.

Color in DLP projection

There are two primary methods by which DLP projection systems create acolor image, those utilized by single-chip DLP projectors, and those used bythree-chip projectors. A third method, sequential illumination by threecolored light emitting diodes, is being developed, and is currently used intelevisions manufactured by Samsung. Yet another method, color LASERs, is

currently in use by Mitsubishi in their LASERVUE products.[2]

In a projector with a single DLP chip, colors are produced either by placing acolor wheel between a white lamp and the DLP chip or by using individual
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light sources to produce the primary colors, LEDs or LASERs for example.The color wheel is divided into multiple sectors: the primary colors: red,green, and blue, and in many cases secondary colors including cyan,magenta, yellow and white. The use of the secondary colors is part of thenew color performance system called BrilliantColor which processes theprimary colors along with the secondary colors to create a broader spectrumof possible color combinations on the screen.

The DLP chip is synchronized with the rotating motion of the color wheel sothat the green component is displayed on the DMD when the green sectionof the color wheel is in front of the lamp. The same is true for the red, blueand other sections. The colors are thus displayed sequentially at asufficiently high rate that the observer sees a composite "full color" image.In early models, this was one rotation per frame. Now, most systems operateat up to 10x the frame rate.

A single-chip projector alternates between colors and produces separate red,green, and blue images when displaying a moving image, or in this case,

illuminating a moving hand.

DLP projectors utilizing a mechanical spinning color wheel may exhibit ananomaly known as the rainbow effect. This is best described as briefflashes of perceived red, blue, and green "shadows" observed most oftenwhen the projected content features high contrast areas of movingbright/white objects on a mostly dark/black background. The scrolling endcredits of many movies are a common example, and also in animationswhere moving objects are surrounded by a thick black outline. Brief visibleseparation of the colours can also be apparent when the viewer moves theireyes quickly across the projected image. Some people perceive these

rainbow artifacts frequently, while others may never see them at all.

This effect is caused by the way the eye follows a moving object on theprojection. When an object on the screen moves, the eye will follow theobject with a constant motion, but the projector will display each alternatingcolor of the frame at the same location, for the duration of the whole frame.So, while the eye is moving, it will see a frame of a specific color (red forexample). Then, when the next color is displayed (green for example),although it gets displayed at the same location overlapping the previouscolor, the eye will have moved toward the object's next frame target. Thus,the eye will see that specific frame color slightly shifted. Then, the thirdcolor gets displayed (blue for example), and the eye will see that frame'scolor slightly shifted again. This effect is not perceived only for the movingobject, but the whole picture.
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The effect varies with the rotational speed of the color wheel and the framerefresh rate of the video signal. There is a maximum rotational speed limitfor the wheel, typically 10,000 to 15,000 RPM. Video framerate is usuallymeasured in frames per second and must be multiplied by 60 to find thewheel speed, whereas 60 frames/sec equals 3,600 frames/minute. If thecolor wheel spins 4 times per frame, it is rotating at a speed of 14,400 RPM.(Projector specifications often list the wheel speed at specific framerates as2x, 3x, 4x, etc.)[3][4] Increasing the video refresh rate to 85 frames persecond does not necessarily further reduce the rainbow effect since this ratewould increase the wheel speed to 20,400 RPM, potentially exceeding thesafe limits of wheel rotation and requiring the projector to drop back to 3xspeed, at 15,300 RPM.

Multi-color LED-based and LASER-based single-chip projectors are able toeliminate the spinning wheel and minimize the rainbow effect since thepulse rate of LEDs and LASERs are not limited by physical motion.

Surface-conduction electron-emitter displayA surface-conduction electron-emitter display (SED) is a flat panel

color television technology currently being developed by a number ofcompanies. SEDs use nanoscopic-scale electron emitters to energize coloredphosphors and produce an image. In a general sense, a SED consists of amatrix of tiny cathode ray tubes, each "tube" forming a single sub-pixel onthe screen, grouped in threes to form red-green-blue (RGB) pixels.

SEDs combine the advantages of CRTs, namely their high contrast ratios,wide viewing angles and very fast response times, with the packaging

advantages ofLCD and other flat panel displays. They also use much lesspower than an LCD television of the same size. To date, however,manufacturing, legal and financial problems have prevented thecommercialization of SED systems.

SEDs are closely related to another developing display technology, the fieldemission display, or FED. The two differ primarily in the details of theelectron emitters.

A conventional cathode ray tube (CRT) is powered by an electron gun,

essentially an open-ended vacuum tube. At one end of the gun electrons areproduced by "boiling" them off a metal filament, which requires relativelyhigh currents and consumes a large proportion of the CRT's power. Theelectrons are then accelerated and focused into a fast-moving beam, flowingforward towards the screen. Electromagnets surrounding the gun end of thetube are used to steer the beam as it travels forward, allowing the beam tobe scanned across the screen to produce a 2D display. When the fast-moving electrons strike phosphor on the back of the screen, light isproduced. Color images are produced by painting the screen with spots orstripes of three colored phosphors, one each for red, green and blue (RGB).When viewed from a distance, the spots, known as "sub-pixels", blend

together in the eye to produce a single colored spot known as a pixel.

The SED replaces the single gun of a conventional CRT with a grid ofnanoscopic emitters, one for each sub-pixel of the display. The surface
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conduction electron emitter apparatus consists of a thin slit across whichelectrons jump when powered with high-voltage gradients. Due to thenanoscopic size of the slits, the required field can correspond to a potentialon the order of tens of volts. A few of the electrons, on the order of 3%,impact with slit material on the far side and are scattered out of the emittersurface. A second field, applied externally, accelerates these scatteredelectrons towards the screen. Production of this field requires kilovoltpotentials, but is a constant field requiring no switching, so the electronicsthat produce it are quite simple.[1]

Each emitter is aligned behind a colored phosphor dot, and the acceleratedelectrons strike the dot and cause it to give off light in a fashion identical toa conventional CRT. Since each dot on the screen is lit by a single emitter,there is no need to steer or direct the beam as there is in an CRT. Thequantum tunneling effect that emits electrons across the slits is highly non-linear, and the process tends to be fully on or off for any given voltage. Thisallows the selection of particular emitters by powering a single horizontal

row on the screen and then powering all of the needed vertical columns atthe same time, thereby powering the selected emitters. Any power leakedfrom one column to surrounding emitters will cause too small a field toproduce a visible output; if that emitter was not turned on the leaked powerwill be too low to switch it, if it was already on the additional power will haveno visible effect. This allows SED displays to work without an active matrix ofthin-film transistors that LCDs and similar displays require, and furtherreduces the complexity of the emitter array. However, this also means thatchanges in voltage cannot be used to control the brightness of the resultingpixels.
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Types Of Printers:

A device that prints text or illustrations on paper. There are manydifferent types of printers.

In terms of the technology utilized, printers fall into the followingcategories:

Daisy Wheel:

A type ofprinter that produces letter-quality type. A daisy-wheelprinter works on the same principle as a ball-head typewriter. The daisywheel is a disk made of plastic or metal on which characters stand out inrelief along the outer edge. To print a character,the printer rotates the diskuntil the desired letter is facing the paper. Then a hammer strikes the disk,forcing the character to hit an ink ribbon, leaving an impression of thecharacter on the paper. You can change the daisy wheel to print different

fonts.

Daisy-wheel printers cannot print graphics, and in general they are noisyand slow, printing from 10 to about 75 characters per second. As the price oflaser and ink-jet printers has declined, and the quality ofdot-matrix printershas improved, daisy-wheel printers have become obsolete.

Ink-jet:

A type ofprinter that works by spraying ionized ink at a sheet ofpaper. Magnetized plates in the ink's path direct the ink onto the paper inthe desired shapes. Ink-jet printers are capable of producing high qualityprint approaching that produced by laser printers. A typical ink-jet printerprovides a resolution of 300 dots per inch, although some newer modelsoffer higher resolutions.
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In general, the price of ink-jet printers is lower than that of laser printers.However, they are also considerably slower. Another drawback of ink-jetprinters is that they require a special type of ink that is apt to smudge oninexpensive copier paper.

Because ink-jet printers require smaller mechanical parts than laser printers,they are especially popular as portable printers. In addition, color ink-jetprinters provide an inexpensive way to print full-color documents

Laser:

A type ofprinter that utilizes a laser beam to produce an image on adrum. The light of the laser alters the electrical charge on the drumwherever it hits. The drum is then rolled through a reservoir oftoner, which

is picked up by the charged portions of the drum. Finally, the toner istransferred to the paper through a combination of heat and pressure. This isalso the way copy machines work.

Because an entire page is transmitted to a drum before the toner isapplied, laser printers are sometimes calledpage printers. There are two

other types ofpage printers that fall under the category oflaser printerseven though they do not use lasers at all. One uses an array ofLEDs to

expose the drum, and the other uses LCDs. Once the drum isCharged ,however they both work like a laser printer

One of the chief characteristics of laser printers is their resolution --how many dots per inch (dpi) they lay down. The available resolutions range

from 300 dpi at the low end to 1,200 dpi at the high end. By comparison,offset printing usually prints at 1,200 or 2,400 dpi. Some laser printersachieve higher resolutions with special techniques known generally asresolution enhancement.

In addition to the standard monochrome laser printer, which uses asingle toner, there also exist color laser printers that use four toners to printin full color. Color laser printers tend to be about five to ten times asexpensive as their monochrome siblings.

Laser printers produce very high-quality print and are capable ofprinting an almost unlimited variety offonts. Most laser printers come with abasic set of fonts, called internal or resident fonts, but you can addadditional fonts in one of two ways:
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font cartridges : Laser printers have slots in which you can insert fontcartridges, ROMboards on which fonts have been recorded. Theadvantage of font cartridges is that they use none of the printer'smemory.soft fonts : All laser printers come with a certain amount ofRAMmemory, and you can usually increase the amount of memory byadding memory boards in the printer's expansion slots. You can thencopy fonts from a disk to the printer's RAM. This is called downloadingfonts. A font that has been downloaded is often referred to as a softfont, to distinguish it from the hard fonts available on font cartridges.The more RAM a printer has, the more fonts that can be downloadedat one time.

Dot-matrix:

A type ofprinter that produces characters and illustrations by strikingpins against an ink ribbon to print closely spaced dots in the appropriateshape. Dot-matrix printers are relatively expensive and do not produce high-quality output. However, they can print to multi-page forms (that is, carboncopies), something laser and ink-jet printers cannot do.

Dot-matrix printers vary in two important characteristics:

speed: Given in characters per second(cps), the speed can varyfrom about 50 to over 500 cps. Most dot-matrix printers offer differentspeeds depending on the quality of print desired. print quality: Determined by the number of pins (the mechanismsthat print the dots), it can vary from 9 to 24. The best dot-matrixprinters (24 pins) can produce near letter-quality type, although you

can still see a difference if you look closely.

Line:

A high-speed printer capable of printing an entire line at one time. Afast line printer can print as many as 3,000 lines per minute. Thedisadvantages of line printers are that they cannot print graphics, the printquality is low, and they are very noisy.
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Thermal:

A printer that uses heat to transfer an impression onto paper.

There are two kinds of thermal printers:

Thermal wax transfer: a printer that adheres a wax-based ink onto

paper. A thermal printhead melts wax-based ink from the transferribbon onto the paper. When cool, the wax is permanent. This type ofthermal printer uses an equivalent panel of ink for each page to beprinted, no matter if a full page or only one line of print is transferred.Monochrome printers have a black page for each page to be printed,while color printers have either three (CMY) or four (CMYK) coloredpanels for each page. Unlikethermal dye transfer printers , also calleddye sublimation printers, these printers print images as dots, whichmeans that images must be dithered first. As a result, images are notquite photo-realistic, although they are very good. The big advantagesof these printers over thermal dye transfer printers are that they don'trequire special paper and they are faster.

Direct thermal: a printer that prints the image by burning dots ontocoated paper when the paper passes over a line of heating elements.Early fax machines used direct thermal printing.

Printers are also classified by the following characteristics:

Quality of type: The output produced by printers is said to be eitherletter quality(as good as a typewriter), near letter quality, or draftquality. Only daisy-wheel, ink-jet, and laser printers produce letter-

quality type. Some dot-matrix printers claim letter-quality print, but ifyou look closely, you can see the difference.Speed: Measured in characters per second (cps) or pages per minute

(ppm), the speed of printers varies widely. Daisy-wheel printers tendto be the slowest, printing about 30 cps. Line printers are fastest (upto 3,000 lines per minute). Dot-matrix printers can print up to 500 cps,and laser printers range from about 4 to 20 text pages per minute.Impact or non-impact: Impact printers include all printers that work

by striking an ink ribbon. Daisy-wheel, dot-matrix, and line printers areimpact printers. Non-impact printers include laser printers and ink-jetprinters. The important difference between impact and non-impact

printers is that impact printers are much noisier.Graphics: Some printers (daisy-wheel and line printers) can print only

text. Other printers can print both text and graphics.
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Digital Camera

A digital camera is an electronic device used to capture and storephotographs electronically in a digital format, instead of using photographicfilm like conventional cameras, or recording images in an analog format tomagnetic tape like many video cameras. Modern compact digital cameras

are typically multifunctional, with some devices capable of recording soundand/or video as well as photographs. In the Western market, digital stillcameras now outsell their 35 mm film counterparts.

Classification

Digital cameras can be classified into several categories:

Live-preview digital cameras

A Live-Preview Digital camera (LPD) is a camera that uses aconventionally generated digital image (live-preview) on an electronicscreen as its principal means of framing and previewing before taking thephotograph. With the exception of very few live-preview DSLRs, any digitalcamera that has live-preview falls into this category.

Many modern LPDs have a movie mode, and a growing number ofcamcorders can take still photographs. However, even a low-end LPD cantake far better still pictures than a mid-range video camera, and mid-rangeLPDs have much lower video quality than low-end Video cameras. Inaddition, some newer camcorders record video directly to flash memory andtransfer over USB and FireWire. Among digital LPDs, most have a rear liquid

crystal display for reviewing photographs.

They are rated in megapixels; that is, the product of their maximumresolution dimensions in millions. The actual transfers to a host computerare commonly carried out using the USB mass storage device class (so thatthe camera appears as a drive) or using the Picture Transfer Protocol and itsderivatives, in addition firewire is becoming more popular and supportedamong more digital cameras. All use either a charge-coupled device (CCD)or a complementary metal-oxide semiconductor (CMOS) sensor or novelsensors based upon either of those two principles, i.e. chips comprised of agrid ofphototransistors to sense the light intensities across the plane of

focus of the camera lens. CMOS sensors are differentiated from CCDs properin that it uses less power and a different kind of light sensing material,however the differences are highly technical and many manufacturers still
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consider the CMOS chip a charged coupled device. For our purposes, a chipsensor is a CCD.

Canon PowerShot A60

Compact digital cameras

Also called digicams, this encompasses most digital cameras. They arecharacterized by great ease in operation and easy focusing; this designallows for limited motion picture capability. They tend to have significantlysmaller zooms than prosumer and DSLR cameras. They have an extendeddepth of field. This allows objects at a larger range of depths to be in focus,which accounts for much of their ease of use. It is also part of the reasonprofessional photographers find their images flat or artificial-looking. Theyexcel in landscape photography and casual use. They typically save picturesin only theJPEG file format.

Bridge cameras

Main article: Bridge digital camera

Prosumer or Bridge digital cameras form a general group of higher endLPDs that physically resemble DSLR cameras and share with these someadvanced features but share with compacts the same basic LPD design.Traditionally DSLRs are considered much more professional than bridgecameras which have so far been prosumer or at best semi-professional.However since the introduction of the Canon EOS Digital Rebel (a small-

sized, low-priced DSLR introduced in 2003) and what followed it of similarentry-level DSLRs from different manufacturers, a new class of DSLR hasemerged and the distinction between bridge versus DSLR as prosumerversus professional cameras has become less black and white than it used
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to be. The new class of DSLRs can be described as consumer (compared tothe higher classes of DSLRs), while the top bridge cameras remain prosumer(compared to compact LPDs). A Comparison between the bridge and entry-level DSLRs would reveal that they are on par. The nameprosumerfromprofessional (or producer) and consumer, means a professional-consumer ora producer-consumer (who is involved somehow in the production of theproduct that they consume).

Bridge cameras tend to have long- or ultrazoom lens, which compromises -invarying degrees, depending on the quality of the zoom lens- a "do it all"ability with barrel distortion and pincushioning. Prosumer cameras aresometimes marketed as and confused with digital SLR cameras since thebodies resemble each other. The distinguishing characteristics are thatprosumer cameras lack the mirror and reflex system of DSLRs, have so farbeen always produced with only one single sealed (non-interchangeable)lens (but accessory wide angle or telephoto converters can be attached tothe front of the sealed lens), can usually take movies, record audio and the

scene composition is done with either the liquid crystal display or theelectronic viewfinder (EVF). The overall performance tends to be slower thana true digital SLR, but they are capable of very good image quality whilebeing more compact and lighter than DSLRs. The high-end models of thistype have comparable resolutions to low and mid-range DSLRs. Many of thethese cameras can save inJPEG or .RAW format.

Method of image capture(Working)

Since the first digital backs were introduced, there have been threemain methods of capturing the image, each based on the hardwareconfiguration of the sensor and color filters.

The first method is often called single-shot, in reference to the numberof times the camera's sensor is exposed to the light passing through thecamera lens. Single-shot capture systems use either one CCD with a Bayerfilter mosaic it, or three separate image sensors (one each for the primaryadditive colors red, green, and blue) which are exposed to the same imagevia a beam splitter.

The second method is referred to as multi-shotbecause the sensor isexposed to the image in a sequence of three or more openings of the lensaperture. There are several methods of application of the multi-shottechnique. The most common originally was to use a single image sensorwith three filters (once again red, green and blue) passed in front of thesensor in sequence to obtain the additive color information. Another multipleshot method utilized a single CCD with a Bayer filter but actually moved thephysical location of the sensor chip on the focus plane of the lens to "stitch"together a higher resolution image than the CCD would allow otherwise. Athird version combined the two methods without a Bayer filter on the chip.

The third method is called scanning because the sensor moves acrossthe focal plane much like the sensor of a desktop scanner. Their linearor tri-linearsensors utilize only a single line of photosensors, or three lines for the
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three colors. In some cases, scanning is accomplished by rotating the wholecamera; a digital rotating line camera offers images of very high totalresolution.

The choice of method for a given capture is of course determinedlargely by the subject matter. It is usually inappropriate to attempt tocapture a subject that moves with anything but a single-shot system.However, the higher color fidelity and larger file sizes and resolutionsavailable with multi-shot and scanning backs make them attractive forcommercial photographers working with stationary subjects and large-format photographs.
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Connectivity

Many digital cameras can connect directly to a computer to transfer data:

Early cameras used the PCserial port. USB is now the most widelyused method ( Most cameras are viewable as USB Mass Storage),though some have a FireWire port. Some cameras use USB PTP modefor connection instead ofUSB MSC; some offer both modes.

Other cameras use wireless connections, via Bluetooth or IEEE 802.11Wi-Fi, such as the KodakEasyShare One.

A common alternative is the use of a card reader which may be capable ofreading several types of storage media, as well as high speed transfer ofdata to the computer. Use of a card reader also avoids draining the camera

battery during the download process, as the device takes power from theUSB port. An external card reader allows convenient direct access to theimages on a collection of storage media. But if only one storage card is inuse, moving it back and forth between the camera and the reader can beinconvenient.

Many modern cameras offer the PictBridge standard, which allows sendingdata directly to printers without the need of a computer.

Storage

Digital cameras need memory to store data. A wide variety of storage mediahas been used. These include:

Onboard flash memoryCheap cameras and cameras secondary to the device's main use (suchas a camera phone).

3.5" floppy disksMainly the Sony Mavica line of the late 1990s.

Video FloppyA 2x2 inch (50 mm 50 mm)floppy disk used for early analogcameras.

PCMCIA hard drivesEarly professional cameras, discontinued.

CD single or DVDa 185 MB small form factor CD, most commonly seen in the Sony CD-1000.

Thermal printerKnown only in one model of camera that printed images immediatelyrather than storing.

Batteries

Digital cameras have high power requirements, and over time have becomeincreasingly smaller in size, which has resulted in an ongoing need to
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develop a battery small enough to fit in the camera and yet able to power itfor a reasonable length of time.

Applications:

Provided here are a few ideas and examples for how digital cameras couldbe used to support education.

Support

Print student or staff ID photos for cards,badges, or special events; create an ID file forschool records.

Create a photo inventory of school propertyfor property records.

Document crime or vandalism for police orinsurance reasons.

Create posters or multimedia displays orpresentations of student activities and workfor open house, awards night, fair displays etc.

Take pictures for school newspapers and localbroadcasts, or even a digital yearbook.

Curriculum

Take students on an electronic field trip byshowing photos of a distant site.

Show students important sites or points aheadof time to highlight spots not to miss.

Review field trips with pictures to show allstudents the sights, discuss learning, sharewith other groups.

Create assignments with pictures andprocesses. For example: lab equipment,measurements, instruments, sports

equipment or positions, recipe ingredients,pictures for vocabulary or reading lessons.

Supplement work sheets with pictures specific
http://en.wikipedia.org/wiki/Battery_(electricity)http://makepopupwin%28%27images/invent.jpg','room%20inventory%20image',240,320,'Take%20images%20of%20inventory')http://makepopupwin%28%27images/fire.jpg','Bus%20fire%20image',480,640,'Highway%20bus%20fire')http://makepopupwin%28%27images/wire_car.jpg','Student%20project%20image',480,640,'Student%20project%20image')http://makepopupwin%28%27images/wire_car.jpg','Student%20project%20image',480,640,'Student%20project%20image')http://makepopupwin%28%27images/newspap.jpg','Student%20with%20award%20image',240,320,'Student%20Awards')http://makepopupwin%28%27images/sub.jpg','Sub%20image',480,640,'Field%20trip%20to%20Sub%20Museum')http://makepopupwin%28%27images/pelican.jpg','Pelican%20image',480,640,'Pelican%20Rescue')http://makepopupwin%28%27images/moonsheet.gif','Moon%20worksheet%20image',959,768,'Moon%20worksheet')http://makepopupwin%28%27images/moonsheet.gif','Moon%20worksheet%20image',959,768,'Moon%20worksheet')http://makepopupwin%28%27images/pelican.jpg','Pelican%20image',480,640,'Pelican%20Rescue')http://makepopupwin%28%27images/sub.jpg','Sub%20image',480,640,'Field%20trip%20to%20Sub%20Museum')http://makepopupwin%28%27images/clouds.jpg','Sunset%20along%20the%20Gulf%20image',480,640,'Sunset%20along%20the%20Gulf,%20Florida')http://makepopupwin%28%27images/newspap.jpg','Student%20with%20award%20image',240,320,'Student%20Awards')http://makepopupwin%28%27images/wire_car.jpg','Student%20project%20image',480,640,'Student%20project%20image')http://makepopupwin%28%27images/fire.jpg','Bus%20fire%20image',480,640,'Highway%20bus%20fire')http://makepopupwin%28%27images/invent.jpg','room%20inventory%20image',240,320,'Take%20images%20of%20inventory')http://makepopupwin%28%27images/cavanac.jpg','Photo%20ID%20image',195,171,'Photo%20ID%20image')http://en.wikipedia.org/wiki/Battery_(electricity)http://makepopupwin%28%27images/invent.jpg','room%20inventory%20image',240,320,'Take%20images%20of%20inventory')http://makepopupwin%28%27images/fire.jpg','Bus%20fire%20image',480,640,'Highway%20bus%20fire')http://makepopupwin%28%27images/wire_car.jpg','Student%20project%20image',480,640,'Student%20project%20image')http://makepopupwin%28%27images/wire_car.jpg','Student%20project%20image',480,640,'Student%20project%20image')http://makepopupwin%28%27images/newspap.jpg','Student%20with%20award%20image',240,320,'Student%20Awards')http://makepopupwin%28%27images/sub.jpg','Sub%20image',480,640,'Field%20trip%20to%20Sub%20Museum')http://makepopupwin%28%27images/pelican.jpg','Pelican%20image',480,640,'Pelican%20Rescue')http://makepopupwin%28%27images/moonsheet.gif','Moon%20worksheet%20image',959,768,'Moon%20worksheet')


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to your setups.

Use with lenses or other optics (microscopes,telescopes, etc.) to make images available tothe entire class.

Customize your displays and bulletin boardswith photos from your school, lab, classroom,or images of student performances.

Create student presentations.

Write thank you letters showingrecipient/sender interaction.

AssessmentInclude students photos and images of their3D and performance work in portfolios. Thepictures will allow you to document a greatervariety of work that would otherwise not beincluded in a portfolio.

Create more authentic evaluations whichinclude images of items or processes fromyour class.
http://makepopupwin%28%27images/lens.jpg','Image%20through%20a%20multifacet%20lens',480,640,'Shooting%20through%20a%20multifacet%20lens')http://makepopupwin%28%27images/school.jpg','Front%20of%20a%20school%20image',480,640,'School%20front')http://makepopupwin%28%27images/civilair.gif','Template%20for%20Civil%20Air%20Patrol%20letters%20image',959,768,'Template%20for%20Civil%20Air%20Patrol%20letters')http://makepopupwin%28%27images/play3.jpg','School%20play%20image',224,375,'School%20Play')http://makepopupwin%28%27images/play3.jpg','School%20play%20image',224,375,'School%20Play')http://makepopupwin%28%27images/civilair.gif','Template%20for%20Civil%20Air%20Patrol%20letters%20image',959,768,'Template%20for%20Civil%20Air%20Patrol%20letters')http://makepopupwin%28%27images/school.jpg','Front%20of%20a%20school%20image',480,640,'School%20front')http://makepopupwin%28%27images/lens.jpg','Image%20through%20a%20multifacet%20lens',480,640,'Shooting%20through%20a%20multifacet%20lens')http://makepopupwin%28%27images/lens.jpg','Image%20through%20a%20multifacet%20lens',480,640,'Shooting%20through%20a%20multifacet%20lens')http://makepopupwin%28%27images/school.jpg','Front%20of%20a%20school%20image',480,640,'School%20front')http://makepopupwin%28%27images/civilair.gif','Template%20for%20Civil%20Air%20Patrol%20letters%20image',959,768,'Template%20for%20Civil%20Air%20Patrol%20letters')http://makepopupwin%28%27images/play3.jpg','School%20play%20image',224,375,'School%20Play')


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STUDYANDSURVEYOF STILLIMAGESCANNERSANDDVDS

TYPESOF SCANNERS

Scanners are not just for scanning pictures. Scanners can read printed textand convert it to files (OCR) that you can manipulate with your word-processing program. You can also scan a handwritten letter and send it byfax directly to somebody, or put it in permanent storage on your hard drive.

Different types of scanners are:

Flatbed Scanners

Flatbed scanners are the best-known and largest selling scanner type, and

with good reason. They're versatile, easy to operate, and widely available.Their popularity for Web publishing has opened up a huge market, pushingprices for entry level units below $100. At the other end, professional unitsfor the color graphics market now rival drum scanners in quality.

All use the same basic technology, in which a light sensor (generally a CCD)and a light source, both mounted on a moving arm, sweep past thestationary document on a glass platen. Automatic document handlers (ADH)are available on some models, and can increase throughput and lessenoperator fatigue for sets of uniform documents in reasonably good condition.

A specialized variant of the flatbed scanner is the overhead book scanner, inwhich the scanner's light source, sensor array and optics are moved to an

overhead arm assembly under which a bound volume can be placed face upfor scanning.

Sheetfeed Scanners

Sheetfeed scanners use the same basic technologyas flatbeds, but maximize throughput, usually at theexpense of quality. Generally designed for high-volume business environments, they typically scanin black and white or gray scale at relatively lowresolutions. Documents are expected to be ofuniform size and sturdy enough to endure fairlyrough handling, although the transport mechanismson some newer models reduces the stress. Using


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roller, belt, drum, or vacuum transport, the light sensor and light sourceremain stationary while the document is moved past. An important subclassof sheetfeed scanners are upright models specifically designed for oversizedocuments such as maps and architectural drawings.

Drum Scanners

Drum scanners produce the highest resolution, highest qualityscans of any scanner type, but at a price. Besides theirexpense, drum scanners are slow, not suitable for brittledocuments and require a high level of operator skill. Thus theyare typically found in service bureaus that cater to the colorpre-press market.

Instead of using CCD technology, drum scanners use PMT (Photo MultiplierTube) technology for greater dynamic range and color accuracy. They alsocost an arm and a leg, Nevertheless, drum scanners offer features not

available to desktop scanners such as direct conversion to CMYK, autosharpening, batch scanning, greater dynamic range, and huge imagescanning areas.

Ironically, most drum scanners dont support preview mode - drum scanneroperators are more interested in numbers than what the see with their eyes.Yet what truly sets drum scanners apart is their increased productivity. Sincethe process of scanning to CMYK is automated, drum scanners can producemore scans per hour than a desktop unit.

Microfilm Scanners

Microfilm scanners are highly specialized devices fordigitizing roll film, fiche, and aperture cards. Gettinggood, consistent quality from a microfilm scanner can bedifficult because they can be operationally complex, filmquality and condition may vary, and because they offerminimal enhancement capability. Only a few companiesmake microfilm scanners, and the lack of competitioncontributes to the high cost of these devices.

Slide Scanners

Slide scanners are used to digitize existing slidelibraries as well as photo intermediates of 3-dimensional objects and documents that are not well-suited for direct scanning, though moreand more such objects will be captureddirectly by digital camera.


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The use of transparent media generally delivers an image with gooddynamic range, but depending on the size of the original, the resolution maybe insufficient for some needs. Throughput can be slow.

Handheld Scanners

Hand scanners are useful for their portability and lowprice (often one-third to a quarter of the cost of a flatbedscanner). Hand scanners generally plug into a computer'sprinting port, as opposed to a SCSI port, allowing them to

be easily shared from workstation to workstation. Manypeople find them ideal for use with a notebook or laptop.Unfortunately, hand scanners are less accurate thanflatbeds because they have weaker light sources andoften produce uneven scans - courtesy of theunsteadiness of your hand or the surface you're standing on. Many handscanners now offer an alignment template to help guide you when scanning.At least one manufacturer ships a motorized "self-propelled" unit to helpstabilize its scanner.

High-end hand scanners offer 400 dpi resolution and 24-bit color - allowing

you to achieve reasonably high-quality results. But their 4" to 5" wide scanhead forces you to make multiple passes to scan even average-sizeddocuments. You'll need to use the supplied stitching software to mergethese partial scans back together again - a time consuming task.Nonetheless, hand scanners are very popular and are capable of high-quality, quick and easy, low-cost scans.

WORKINGOF SCANNERS

Carbon-copying, photocopying, these were more apt technologies for text,

scanning now, is the most popular way of reproducing images, which can beplayed around with too! The scanner has a scanning area, which is a glasssurface and when the picture/photo/object is kept on the surface, a lightsource illuminates the object and the reflection from the surface of theobject is trapped by sensing (photoelectric devices).

This resultant image is sharp and clear,and is converted into digital informationthat can be read by a computer. Onecan actually capture a true copy andeven minor details of it by using ascanner, something that was notpossible earlier.


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When you scan an image it is illuminated by a light source. The light is thenreflected back off the image. This reflected light is of different intensitydepending on the light /dark areas of the document. This light goes througha lens, and measured by the CCDs.

CCDs are linear charged-coupled device (CCD) array. The CCD, which is aphotometer, converts the light measurement to an analogue voltage. Thisanalogue voltage is then converted to a digital value by categorizing theinformation into values based on the intensity of the light detected.


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HOW DO SCANNERS WORK?

Carbon-copying, photocopying, these were more apt technologies fortext, scanning now, is the most popular way of reproducing images, whichcan be played around with too! The scanner has a scanning area, which is a

glass surface and when the picture/photo/object is kept on the surface, alight source illuminates the object and thereflection from the surface of the object is trapped by sensing (photoelectric devices).

This resultant image is sharp and clear, and is converted into digital information thatcan be read by a computer. One can actually capture a true copy and even minor details ofit by using a scanner, something that was not possible earlier.

Use Of Cold Cathode Diode(CCD)

When you scan an image it is illuminated by a light source. The light is then reflected

back off the image. This reflected light is of different intensity depending on the light /darkareas of the document. This light goes through a lens, and measured by the CCDs.

CCDs are linear charged-coupled device (CCD) array. The CCD, which is aphotometer, converts the light measurement to an analogue voltage. This analogue voltageis then converted to a digital value by categorizing the information into values based on theintensity of the light detected. The entire information is then sent to the softwareapplication that organizes the information (into bits and bytes) presenting it on the monitor.

Properties Of CCD


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DVD

For the binocular vision condition, see Dissociated Vertical Deviation.

DVD

DVD-R read/write side

Media type Optical disc

Capacity

4.7 GB (single-sided, single-layer)

8.5 GB (single-sided, double-layer)

9.4 GB (double-sided, single-layer)

17.08 GB (double-sided, double-layer rare)

Read mechanism 650 nm laser, 10.5 Mbit/s (1)

Write mechanism 10.5 Mbit/s (1)

Standard DVD Forum's DVD Books and DVD+RW Alliance specifications

DVD, also known as Digital Versatile Disc or Digital Video Disc, is an opticaldiscstorage media format, and was invented and developed by Sony, andPhilips in 1995. Its main uses are video and data storage. DVDs are of thesame dimensions as compact discs (CDs), but store more than six times asmuch data.

Variations of the term DVD often indicate the way data is stored on thediscs: DVD-ROM (read only memory) has data that can only be read and notwritten; DVD-R and DVD+R (recordable) can record data only once, and thenfunction as a DVD-ROM; DVD-RW (re-writable), DVD+RW, and DVD-RAM

(random access memory) can all record and erase data multiple times. Thewavelength used by standard DVD lasers is 650 nm;[4] thus, the light has ared color.

DVD-Video and DVD-Audio discs refer to properly formatted and structuredvideo and audio content, respectively. Other types of DVDs, including thosewith video content, may be referred to as DVD Data discs.
http://en.wikipedia.org/wiki/Dissociated_Vertical_Deviationhttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/Megabit_per_secondhttp://en.wikipedia.org/wiki/Megabit_per_secondhttp://en.wikipedia.org/wiki/International_standardhttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Data_storage_devicehttp://en.wikipedia.org/wiki/Sonyhttp://en.wikipedia.org/wiki/Philipshttp://en.wikipedia.org/wiki/Videohttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/CDhttp://en.wikipedia.org/wiki/DVD-Rhttp://en.wikipedia.org/wiki/DVD%2BRhttp://en.wikipedia.org/wiki/DVD-RWhttp://en.wikipedia.org/wiki/DVD%2BRWhttp://en.wikipedia.org/wiki/DVD-RAMhttp://en.wikipedia.org/wiki/DVD#cite_note-3http://en.wikipedia.org/wiki/Redhttp://en.wikipedia.org/wiki/DVD-Videohttp://en.wikipedia.org/wiki/DVD-Audiohttp://en.wikipedia.org/wiki/File:DVD.pnghttp://en.wikipedia.org/wiki/File:DVD_logo.svghttp://en.wikipedia.org/wiki/Dissociated_Vertical_Deviationhttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/Megabit_per_secondhttp://en.wikipedia.org/wiki/Megabit_per_secondhttp://en.wikipedia.org/wiki/International_standardhttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Optical_dischttp://en.wikipedia.org/wiki/Data_storage_devicehttp://en.wikipedia.org/wiki/Sonyhttp://en.wikipedia.org/wiki/Philipshttp://en.wikipedia.org/wiki/Videohttp://en.wikipedia.org/wiki/Datahttp://en.wikipedia.org/wiki/CDhttp://en.wikipedia.org/wiki/DVD-Rhttp://en.wikipedia.org/wiki/DVD%2BRhttp://en.wikipedia.org/wiki/DVD-RWhttp://en.wikipedia.org/wiki/DVD%2BRWhttp://en.wikipedia.org/wiki/DVD-RAMhttp://en.wikipedia.org/wiki/DVD#cite_note-3http://en.wikipedia.org/wiki/Redhttp://en.wikipedia.org/wiki/DVD-Videohttp://en.wikipedia.org/wiki/DVD-Audio


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DVD capacity

Capacity and nomenclature[19][20]

SS = single-sided, DS = double-sided, SL = single-layer, DL

= dual-layer

DesignationSide

s

Layers

(total)

Diameter

Capacity

(cm) (GB) (GiB)

DVD-1[21] SS SL 1 1 8 1.46 1.36

DVD-2 SS DL 1 2 8 2.66 2.47

DVD-3 DS SL 2 2 8 2.92 2.72

DVD-4 DS DL 2 4 8 5.32 4.95

DVD-5 SS SL 1 1 12 4.70 4.38

DVD-9 SS DL 1 2 12 8.54 7.95

DVD-10 DS SL 2 2 12 9.40 8.75

DVD-14DSDL/SL

2 3 1213.2

412.3

3

DVD-18 DS DL 2 4 1217.0

815.9

0

The basic types of DVD (12 cm diameter, single-sided or homogenousdouble-sided) are referred to by a rough approximation of their capacity ingigabytes. In draft versions of the specification, DVD-5 indeed held fivegigabytes, but some parameters were changed later on as explained above,

so the capacity decreased. Other formats, those with 8 cm diameter andhybrid variants, acquired similar numeric names with even larger deviation.

The 12 cm type is a standard DVD, and the 8 cm variety is known as aMiniDVD. These are the same sizes as a standard CD and a mini-CD,respectively. The capacity by surface (MiB/cm2) varies from 6.92 MiB/cm2 inthe DVD-1 to 18.0 MiB/cm2 in the DVD-18.

As with hard disk drives, in the DVD realm, gigabyte and the symbol GB areusually used in the SI sense (i.e., 109, or 1,000,000,000 bytes). Fordistinction, gibibyte (with symbol GiB) is used (i.e., 230, or 1,073,741,824

bytes). Most computer operating systems display file sizes in gibibytes,mebibytes, and kibibytes, labeled as gigabyte, megabyte, and kilobyte,respectively.
http://en.wikipedia.org/wiki/DVD#cite_note-18http://en.wikipedia.org/wiki/DVD#cite_note-19http://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/Gibibytehttp://en.wikipedia.org/wiki/DVD#cite_note-DVD_Demystified-20http://en.wikipedia.org/wiki/DVD_formatshttp://en.wikipedia.org/wiki/MiniDVDhttp://en.wikipedia.org/wiki/Mini_CDhttp://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Gibibytehttp://en.wikipedia.org/wiki/Mebibytehttp://en.wikipedia.org/wiki/Kibibytehttp://en.wikipedia.org/wiki/File:Dvdpencilrsizecomparison.pnghttp://en.wikipedia.org/wiki/File:Dvdpencilrsizecomparison.pnghttp://en.wikipedia.org/wiki/DVD#cite_note-18http://en.wikipedia.org/wiki/DVD#cite_note-19http://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/Gibibytehttp://en.wikipedia.org/wiki/DVD#cite_note-DVD_Demystified-20http://en.wikipedia.org/wiki/DVD_formatshttp://en.wikipedia.org/wiki/MiniDVDhttp://en.wikipedia.org/wiki/Mini_CDhttp://en.wikipedia.org/wiki/Gigabytehttp://en.wikipedia.org/wiki/SIhttp://en.wikipedia.org/wiki/Gibibytehttp://en.wikipedia.org/wiki/Mebibytehttp://en.wikipedia.org/wiki/Kibibyte


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Size comparison: a 12 cm DVD+RW and a 19 cm pencil.

Each DVD sector contains 2,418 bytes of data, 2,048 bytes of which are userdata. There is a small difference in storage space between + and - (hyphen)formats:
http://en.wikipedia.org/wiki/DVD%2BRWhttp://en.wikipedia.org/wiki/Pencilhttp://en.wikipedia.org/wiki/DVD%2BRWhttp://en.wikipedia.org/wiki/Pencil


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DVD Video

DVD Video is a standard for content on DVD media. The format went on salein Japan on November 1, 1996, in the United States on March 1, 1997, in

Europe on October 1, 1998 and in Australia on February 1, 1999.[26] DVDbecame the dominant form of home video distribution in Japan when it firstwent on sale in 1996, but did not become the dominant form of home videodistribution in the United States until June 15, 2003, when weekly DVD Videoin the United States rentals began outnumbering weekly VHS cassetterentals, reflecting the rapid adoption rate of the technology in the U.S.marketplace.[5][27] Currently, DVD Video is the dominant form of home videodistribution worldwide, although it was surpassed by Blu-ray Disc inJapanwhen Blu-ray first went on sale in Japan on March 31, 2006.

DVD AudioDVD Audio is a format for delivering high fidelity audio content on a DVD. Itoffers many channel configuration options (from mono to 5.1 surroundsound) at various sampling frequencies (up to 24-bits/192 kHz versusCDDA's 16-bits/44.1 kHz). Compared with the CD format, the much higher-capacity DVD format enables the inclusion of considerably more music (withrespect to total running time and quantity of songs) and/or far higher audioquality (reflected by higher sampling rates and greater sample resolution,and/or additional channels for spatial sound reproduction).

Despite DVD Audio's superior technical specifications, there is debate as towhether the resulting audio enhancements are distinguishable in typicallistening environments. DVD Audio currently forms a niche market, probablydue to the very sort of format war with rival standard SACD that DVD Videoavoided.

DVD as a backup medium

There are two considerations for a backup medium: obsolescence anddurability. If there is no device that can read the medium, it is obsolete and

the data is unavailable and thus lost.

Durability of DVDs is measured by how long the data may be read from thedisc, assuming compatible devices exist that can read it: that is, how longthe disc can be stored until data is lost. Five factors affect durability: sealingmethod, reflective layer, organic dye makeup, where it was manufactured,and storage practices.[35]

The longevity of the ability to read from a DVD+R or DVD-R, is largelydependent on manufacturing quality[36] ranging from 2 to 15 years,[37][38][39]

and is believed to be an unreliable medium for backup unless great care istaken for storage conditions and handling.
http://en.wikipedia.org/wiki/DVD#cite_note-25http://en.wikipedia.org/wiki/DVD#cite_note-ecommerceandvideodistributiondvd.blogspot.com-4http://en.wikipedia.org/wiki/DVD#cite_note-26http://en.wikipedia.org/wiki/Blu-ray_Dischttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/Monauralhttp://en.wikipedia.org/wiki/Surround_soundhttp://en.wikipedia.org/wiki/Surround_soundhttp://en.wikipedia.org/wiki/Compact_Disc_Digital_Audiohttp://en.wikipedia.org/wiki/Sampling_ratehttp://en.wikipedia.org/wiki/Spatial_soundhttp://en.wikipedia.org/wiki/Super_Audio_CDhttp://en.wikipedia.org/wiki/Backuphttp://en.wikipedia.org/wiki/Obsolescencehttp://en.wikipedia.org/wiki/DVD#cite_note-adterrasperaspera.com-34http://en.wikipedia.org/wiki/DVD#cite_note-35http://en.wikipedia.org/wiki/DVD#cite_note-36http://en.wikipedia.org/wiki/DVD#cite_note-37http://en.wikipedia.org/wiki/DVD#cite_note-38http://en.wikipedia.org/wiki/DVD#cite_note-25http://en.wikipedia.org/wiki/DVD#cite_note-ecommerceandvideodistributiondvd.blogspot.com-4http://en.wikipedia.org/wiki/DVD#cite_note-26http://en.wikipedia.org/wiki/Blu-ray_Dischttp://en.wikipedia.org/wiki/Japanhttp://en.wikipedia.org/wiki/Monauralhttp://en.wikipedia.org/wiki/Surround_soundhttp://en.wikipedia.org/wiki/Surround_soundhttp://en.wikipedia.org/wiki/Compact_Disc_Digital_Audiohttp://en.wikipedia.org/wiki/Sampling_ratehttp://en.wikipedia.org/wiki/Spatial_soundhttp://en.wikipedia.org/wiki/Super_Audio_CDhttp://en.wikipedia.org/wiki/Backuphttp://en.wikipedia.org/wiki/Obsolescencehttp://en.wikipedia.org/wiki/DVD#cite_note-adterrasperaspera.com-34http://en.wikipedia.org/wiki/DVD#cite_note-35http://en.wikipedia.org/wiki/DVD#cite_note-36http://en.wikipedia.org/wiki/DVD#cite_note-37http://en.wikipedia.org/wiki/DVD#cite_note-38


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According to the Optical Storage Technology Association (OSTA),"manufacturers claim life spans ranging from 30 to 100 years for DVD, DVD-R and DVD+R discs and up to 30 years for DVD-RW, DVD+RW and DVD-RAM".
http://en.wikipedia.org/wiki/Optical_Storage_Technology_Associationhttp://en.wikipedia.org/wiki/Optical_Storage_Technology_Association


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/*

Problem Definition: Program To Implement Huffman Encoding

*/

#include

#include

#include

#define MAXBITS 50

#define MAXSYMB 50

#define MAXNODES 99

struct nodes

{ int data;

struct nodes *next;

};

struct codetype

{ int bits[MAXBITS];

int startpos;

};

struct nodetype

{ int freq;

int father;

int isleft;

};

void pqinsert(struct nodes **p,int val)

{ struct nodes *newnode,*temp,*prev;

newnode=(struct nodes *)malloc(sizeof(struct nodes));

newnode->data=val;


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temp=*p;

while(temp!=NULL&&temp->datanext;

}

if(temp==*p)

{ newnode->next=*p;

*p=newnode;

}

else

{ newnode->next=prev->next;

prev->next=newnode;

}

}

int pqmindelete(struct nodes **p)

{ struct nodes *temp;

int val;

if(*p==NULL)

return -1;

else

{ temp=*p;

*p=temp->next;

val=temp->data;

return val;

}

}

void main()


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{ struct codetype cd,code[MAXSYMB];

struct nodetype node[MAXNODES];

int i,k,n,p,p1,p2,root;

char symb,alph[MAXSYMB];

struct nodes *rootnodes=NULL;

for(i=0;i


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root=pqmindelete(&rootnodes);

for(i=0;i


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getch();

}

Enter number of symbols

5Enter symbol and frequencya 7b 9c 11d 13e 15

Huffman codes area 7 110b 9 111c 11 00d 13 01e 15 10


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/*

Problem Definition: Program to implement run length encoding.

*/

#include

#include

#include

void main()

{

char str[100];

int i,n,j,count=1;

clrscr();

printf("\t\t******RUN LENGTH ENCODING******");

printf("\nENTER THE STRING:");

gets(str);

printf("\nTHE RUN LENGTH CODE IS:");

for(j=0;str[j]!=NULL;j++)

{

count=1;

while(str[j]!=NULL)

{

if(str[j]==str[j+1])

{

count++;

j++;

}

else

break;

}


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if(count>3)

{

printf("$%d%c",count,str[j]);

}

else

{

for(int kk=0;kk


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