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Computer Graphics

Introduction

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What is computer graphics

Computer graphics is concerned with producing images and animations (or sequences of images) using a computer.

This includes the hardware and software systems used to make these images.

many software systems have been developed for generating computer graphics

This can include systems for producing 3-dimensional models of the scene to be drawn, the rendering software for drawing the images, and the associated user-interface software and hardware.

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What is image

An image (from Latin: imago) is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.

Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue or hologram.

They may be captured by optical devices—such as cameras, mirrors, lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces.

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Computer Graphics Applications

1-Graphs and charts :

A type of information graphic that represent tabular numeric data . They are used to :

make it easier to understand large quantities of data . make it easier to show relationships .

Can be 2-D or 3-D.

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Computer Graphics Applications

Fig a. 2D graphs and charts

Fig b.3D graphs for dramatic effect

Fig c. 3D bar charts on the surface of a geographical region

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Graphics Applications (cont)

2-Computer Aided Design(CAD) Most products are now computer designed. CAD or CADD (Computer-aided drafting and design): methods used in

design. Allow to see the effects of interactive adjustments Application areas:

Design of automobiles, computers, textiles…… Architecture design: floor plan, wiring or electronic outlets, lighting simulations…… Engineering circuit design and network design

Computer Aided Design

Multiple windows, color coded CAD workstation displays

Computer Aided Design

Fig a. Simulation of vehicle performance

Fig b. Architectural visualization of an atrium

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Graphics Applications (cont)

3- Virtual Reality Environment (VR) Interact with the objects in a three-dimensional

environments Based on animation . Animations in virtual reality environments helps in

analyzing interactive effects Used in games and training .

Graphics Applications (cont)

e.g. Train heavy-equipment operators

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Graphics Applications (cont)

4-data Visualization : Scientific Visualization : producing presentations for

scientific ,engineering and medical data sets(ex: DNA , Human Body ).

Business visualization: visual presentation for data sets related to commerce , industry and other nonscientific areas .

Analyzing very large amount of information. Study the behavior of highly complex processes.

Ex: analyzing satellite images, pollution over earth , modeling ocean floor .

Data Visualization

Fig a. Mathematical curve functions plottedin various color combinations

Fig b. Color-coded plot of relative brightness observedfor the Whirlpool Nebula reveals two distinct galaxies

Data Visualization

Fig a. Numerical model of airflow inside a thunderstorm

Fig b. Visualization of stream surfaces flowing past a space shuttle

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Graphics Applications (cont)

5-Education and Training: Educations aids: computer-generated models of

physical, financial and economic systems Special hardware devices are designed Examples:

Training of ship captains, aircraft pilots, heavy-equipment operators……

Education and training

Various special hardware setting for simulation

Education and training

The interior of automobile simulation and street-scene view

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Graphics Applications (cont)

6-Computer Art : Including special S/W & H/w (ex: paintbrush). Fine art : pictures are produced by computers

using stylus (simulate paint stroke, brush width , colors type (oily , pasteel ,etc..)).

Commercial art: logos , advertizing . Can use visualization and other techniques. Morphing: transforming a shape into another .

Computer Art

Fig a. Electronic painting “Sphere of Influence”

Fig b. Creation based on visualization of“Fermat’s Last Theorem”

Computer Art

Fig a. Three-dimension rendering logo

Fig b. Synthesize form and color with musical composition

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Graphics Applications (cont)

7-Entertainment:TV programs use animation , to combine computer generated figures of people , animals , and cartoon characters with actors in the scene .

Use morphing and other utilities like VR . Ex: computer games,… .

Entertainment

Animated characters from the film“Final Fantasy – The Spirits Within”

Entertainment

Examples of morphing from the David Byrne video

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Graphics Applications (cont)

8-Image Processing (IP): Concerns with improving image quality , analyzing

images , recognize visual patterns . CG methods are being used in IP and vise versa A photograph must be digitized before being used

in IP Applications. Ex: used to analyze satellite images . Used in medicine to improve x-rays quality .

Image Processing

Fig a. Computer animation visualizingcardiac activation level

Fig b. One image from a stereoscopic pair, showing the bones of human hand

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Graphics Applications (cont)

9- graphical User Interface (GUI): Contains windows ,menus, icons . Icons are preferred over textual presentations

because:

1. Use less space on the screen .

2. Easier to understand.