Computer Computer GraphicsGraphics

Prepared by Dragon Lee Prepared by Dragon Lee

1 January 20031 January 2003

Use of Computer GraphicsUse of Computer Graphics

MoviesMovies GamesGames Medical ImagingMedical Imaging Computer Aided DesignComputer Aided Design Scientific VisualizationScientific Visualization Graphics User InterfacesGraphics User Interfaces PresentationPresentation

http://www.ethereal3d.com/Portfolio/Animations/index.htmlhttp://www.cs.utah.edu/research/areas/graphics/

Concept & TerminologyConcept & Terminology

Pixel – Pixel – basic element of a bitmap basic element of a bitmap graphics.graphics.

Resolution – Resolution – the no. of pixels in horizontal the no. of pixels in horizontal and vertical dimension.and vertical dimension.

Colors – the RED, GREEN, BLUE value of Colors – the RED, GREEN, BLUE value of a pixel. a pixel.

Gray Levels – 256 gray levelsGray Levels – 256 gray levels Objects – graphics elements that can move Objects – graphics elements that can move

freely.freely.

Types of Computer Types of Computer GraphicsGraphics

Bitmap Graphics Bitmap Graphics Based on pixelsBased on pixels Does not scale wellDoes not scale well Jagged(Jagged( 起鋸齒起鋸齒 ) after enlargement) after enlargement

Vector GraphicsVector Graphics Based on mathematical formulaBased on mathematical formula Scale wellScale well

Creating & Editing a graphic Creating & Editing a graphic imageimage

Drawing primitive:Drawing primitive: Dots, lines, curves, circles, ellipse, rectangles.Dots, lines, curves, circles, ellipse, rectangles.

Painting:Painting: Color fillColor fill

Editing operations:Editing operations: ScaleScale TransformTransform Group and UngroupGroup and Ungroup Merge (combine all objects/layers into background Merge (combine all objects/layers into background

layer)layer) Flip horizontal / verticalFlip horizontal / vertical RotateRotate

Presentation GraphicsPresentation Graphics

Presentation SoftwarePresentation Software Eg. Microsoft PowerPointEg. Microsoft PowerPoint

Reminder on using presentation softwareReminder on using presentation software Apply a template to save your valuable time.Apply a template to save your valuable time. Use transition effects and building effects to enrUse transition effects and building effects to enr

ich your presentation visually.ich your presentation visually. Control the time of your slide show to achieve aControl the time of your slide show to achieve a

utomation.utomation. Add Sounds to your presentationAdd Sounds to your presentation

Common graphics formatCommon graphics format

GIF (Widely used on the Internet)GIF (Widely used on the Internet) Animated GIF (Widely used on the Internet)Animated GIF (Widely used on the Internet) JPG/JPEG (Widely used on the Internet)JPG/JPEG (Widely used on the Internet) Bmp (Windows graphics format)Bmp (Windows graphics format) Psd (PhotoShop file format)Psd (PhotoShop file format) Ufo (PhotoImpact file format)Ufo (PhotoImpact file format) Ai (adobe illustrator – Vector)Ai (adobe illustrator – Vector) Fla / swf (Macromedia Flash -- Vector)Fla / swf (Macromedia Flash -- Vector)

ReferenceReference

The Mathematics of Web DesignThe Mathematics of Web Design http://www.math.arizona.edu/~mcenter/maw/wehttp://www.math.arizona.edu/~mcenter/maw/we

b/b/ VRML SitesVRML Sites

http://www.itl.nist.gov/iaui/ovrt/vrmlexamples.hthttp://www.itl.nist.gov/iaui/ovrt/vrmlexamples.htmlml

http://www-vrl.umich.edu/NewMidfield/index.hthttp://www-vrl.umich.edu/NewMidfield/index.htmlml

http://www.nyx.net/~cmaarbj/vrml/http://www.nyx.net/~cmaarbj/vrml/ http://www.sci.utah.edu/http://www.sci.utah.edu/