Computer Graphics Sec b

8/8/2019 Computer Graphics Sec b

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COMPUTERCOMPUTER

GRAPHICSGRAPHICS


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WHAT IS GRAPHICS ?WHAT IS GRAPHICS ?

COMPUTER GRAPHICSCOMPUTER GRAPHICSARE GRAPHICSARE GRAPHICS

CREATED USING COMPUTER AND MORECREATED USING COMPUTER AND MORE

GENERALLY THE REPRESENTATION ANDGENERALLY THE REPRESENTATION AND

MANIPULATION OF PICTORIAL DATA BY AMANIPULATION OF PICTORIAL DATA BY ACOMPUTERCOMPUTER

IT GENERALLY MEANS CREATIONIT GENERALLY MEANS CREATION

STORAGE AND MANIPULATION OF MODELSSTORAGE AND MANIPULATION OF MODELS

AND IMAGES .AND IMAGES .

The phrase ComputerThe phrase Computer Graphics wasGraphics was

coined in 1960 bycoined in 1960 by William FetterWilliam Fetter,,


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Different Terminologies Used In Graphics :Different Terminologies Used In Graphics :

PIXELPIXEL -- AA pixelpixel is the smallest piece ofis the smallest piece ofinformation in an image. Pixels are normallyinformation in an image. Pixels are normally

arranged in a regular 2arranged in a regular 2--dimensional grid, anddimensional grid, and

are often represented using dots or squares.are often represented using dots or squares.

IMAGEIMAGE -- imageimage ororpicturepicture is an artifact, usuallyis an artifact, usually

twotwo--dimensional, that has a similar appearancedimensional, that has a similar appearance

to someto some subjectsubjectusually a physical object or ausually a physical object or apersonperson. Images may be two. Images may be two--dimensionaldimensional, such, such

as aas a photographphotograph, screen display, and as well as, screen display, and as well as

a threea three--dimensional, such as adimensional, such as a statuestatue..


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RASTERRASTER -- AA raster graphicsraster graphics image orimage orbitmapbitmap isis

aa data structuredata structure representing a generallyrepresenting a generally

rectangularrectangulargrid ofgrid ofpixelspixels, or points of, or points ofcolorcolor,,viewable via aviewable via a monitormonitor,, paperpaper, or other display, or other display

medium.medium.

VECTORVECTOR -- Vector graphicsVector graphics formats areformats are

complementary tocomplementary to raster graphicsraster graphics, which is the, which is the

representation of images as an array ofrepresentation of images as an array ofpixelspixels,,as it is typically used for the representation ofas it is typically used for the representation of

photographic images.photographic images.


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RENDERINGRENDERING -- RenderingRendering is the process ofis the process ofgenerating an image from agenerating an image from a modelmodel, by means of, by means of

computer programs. The model is a descriptioncomputer programs. The model is a descriptionof three dimensional objects in a strictly definedof three dimensional objects in a strictly defined

language or data structure .language or data structure .


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APPLICATIONS OF GRAPHICS :APPLICATIONS OF GRAPHICS :

ININBUSINESS:BUSINESS:

CampaignsCampaigns

BannersBanners

BrochuresBrochuresInternet websites &Internet websites &

AdvertisementsAdvertisements

INEntertainment:

Modern games

Morphing

Animations

Music videos


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IN Medical Science :IN Medical Science :

Graphics are needed in order to betterGraphics are needed in order to bettertrain medical students and doctors .train medical students and doctors .

Allow errors to be made on virtual ratherAllow errors to be made on virtual ratherthan real patientsthan real patients

Alleviate the animal rights controversyAlleviate the animal rights controversyand the shortage of cadavers problemand the shortage of cadavers problem

Permit efficacious treatment for patients.Permit efficacious treatment for patients.

Allow reduction in medical costs (lessAllow reduction in medical costs (lessliability suits, cheaper trainingliability suits, cheaper training --emergency response).emergency response).


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IN IMAGE PROCESSING :IN IMAGE PROCESSING :

Concerned with analysis andConcerned with analysis andmanipulation of images bymanipulation of images bycomputers.computers.

It improves picture quality.It improves picture quality.

Machine perception of visualMachine perception of visual

information, as used in robotics.information, as used in robotics.

IN COMPUTER AIDED DESIGN:IN COMPUTER AIDED DESIGN:

BuildingsBuildingsAutomobilesAutomobiles

Aircraft , spacecraft , watercraft .Aircraft , spacecraft , watercraft .

TextilesTextilesCOMPUTERSCOMPUTERS


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GRAPHIC DEVICESGRAPHIC DEVICES

DISPLAY DEVICES IN GRAPHICS :DISPLAY DEVICES IN GRAPHICS :

LCD ,CRT ,LED , PLASMALCD ,CRT ,LED , PLASMA

INPUT DEVICES :INPUT DEVICES :TRACKBALLS AND SPACEBALLS , JOYSTICS , IMAGETRACKBALLS AND SPACEBALLS , JOYSTICS , IMAGE

SCANNERS , TOUCH PANELS , LIGHT PENSSCANNERS , TOUCH PANELS , LIGHT PENS etc.etc.

TWO MAJOR CATEGORIES:TWO MAJOR CATEGORIES:SOFTWARESOFTWARE The display systems where graphics are rendered in theThe display systems where graphics are rendered in the

co mole screen of the computer (this may be realized on paper).co mole screen of the computer (this may be realized on paper).

HARDWAREHARDWARE The hardware components with which the user interactsThe hardware components with which the user interactsto generate necessary instructions for the execution of required graphics.to generate necessary instructions for the execution of required graphics.


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2 D and 3 D TRANSFORMATIONS:2 D and 3 D TRANSFORMATIONS:

2D2D computer graphicscomputer graphics

ItIt is theis the computercomputer--based generation ofbased generation ofdigitaldigital

imagesimagesmostly from twomostly from two--dimensional models,dimensional models,

such assuch as 2D geometric models2D geometric models ..

These are mainly used in applications that

were originally developed upon traditional

printing and drawing technologies, such as

typography, cartography, technical drawing,

advertising, etc.

2D graphics started in the 1950s, based on

vector graphics devices .


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3 D computer graphics3 D computer graphics

3D graphics are graphics that use a three3D graphics are graphics that use a three--

dimensional representation of geometric datadimensional representation of geometric data(often(often CartesianCartesian) that is stored in the) that is stored in the

computer for the purposes of performingcomputer for the purposes of performing

calculations and rendering 2D images.calculations and rendering 2D images.

These are often referred to asThese are often referred to as 3D models3D models. Apart. Apartfrom the rendered graphic, the model isfrom the rendered graphic, the model is

contained within the graphical data filecontained within the graphical data file ..

A model can be displayed visually as a twoA model can be displayed visually as a two--dimensional image through a process calleddimensional image through a process called

3D rendering3D rendering,, or used in nonor used in non--graphicalgraphical

computer simulationscomputer simulations and calculations.and calculations.


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Computer Graphics Sec b

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