Graphics

Objectives

Explain why graphic images are vital to multimedia applications List the different ways graphics can be used in multimedia

applications Describe the different technologies that can be used to capture digital

images List several sources of still images List the four items that should be logged in reference to graphic

images Discuss the responsibilities of a graphics designer Define common terms used in computer graphics Describe some of the common tools found on a tool palette

Objectives

Explain the difference between paint programs and draw programs Explain the difference between bitmapped graphics and vector-based

graphics Describe several features of common graphics programs Explain jaggies and how they occur Explain the process of creating 3D graphics Discuss the different types of images that can be used in a multimedia

application Discuss the two different types of resolution related to graphic images Explain several disadvantages of high resolution graphics Discuss copyright law as it applies to graphic images

Introduction

backgrounds buttons icons navigation bars charts/graphs Photographs 3D

Digitized Images

converting images into a format the computer can understand

series of 0’s and 1’s

Methods of Creating Graphics

Draw Programs Paint Programs Scanners Video Capture Cards Snappy Photo CD

Types of Images

Line Art - black and white/flat colors Grayscale - 256 levels of gray Color - 4-bit to 36-bit (RGB) 2D or 3D - (3D Web = VRML or Live3D) Hypergraphics - (image map)

Image Quality

bit or color resolution– number of colors in each pixel– also called bit or pixel depth

most common ranges are 8-, 16-, and 24-bit images with greater bit resolutions will be

more colorful and of higher quality image resolution (measured in ppi)

– amount of information stored for each image

Image Compression

compression - an algorithm used to create smaller file sizes

lossy - expendable data is actually lost lossless - none of the data is actually lost;

mathematical algorithms eliminate redundant data.

Graphics Software Paint Programs and Bitmapped Graphics

– stored as pixels– pixels record the screen location and color value on

a bitmap– jaggies/staircasing

Features– Geometric Figures– Edit– Add Color and Patterns– Cut and Paste – Rotate and Stretch

Graphics Software Draw Programs and Vector Graphics

– vector-based images - created and recreated from mathematical models

Features– Fully Editable Shapes – Bézier Curves– Gradient Fill– Blending– Grouping Objects– Rasterize

Graphics Software 3D Modeling Programs

– 3D objects - created using geometric forms or wire frame models

– surfaces/textures are mapped to the models– rendering - converting 3D images to 2D

Features– Modeling– Arranging and Deforming Objects– Shading– Setting Lights and Cameras– Rendering

3-D Drawing•3-D software usually offers:

Directional lighting

Motion

Different perspectives

3-D Drawing

3-D objects combine various

shapes

3-D Drawing

Shapes can be extruded…

3-D Drawing

…or lathed

3-D Drawing

A scene can use different types of shading

Gourand shading

Ray tracing

Flat shading

Phong shading

Graphics Software Image Editing Programs

– manipulate existing images Features

– Cropping– Brightness, Contrast, and Color Correction– Filters– Layering– File Format Conversion

Image Enhancement Plug-Ins

File Formats

– TIFF (Tagged Image File Format)– EPS (Encapsulated PostScript)– BMP (short for Bitmap)– DIB (Device-Independent Bitmap)– GIF (Graphics Interchange Format)– PCX – PICT/PICT2 (short for Picture)– JPEG (Joint Photographic Experts Group)

File Formats– TARGA– Photoshop Native– MacPaint– PIC– PCD (Photo CD)– Plot File– AutoCAD– Windows Metafile (WMF)– Word Perfect Graphics (WPG)

Sources of Still Images

Commercial Image Providers/Stock Photography Houses

Clip Art Photographs Digital Video Charts Maps

Copyright

assume an image is copyright protected 1976 Federal Copyright Act

– property of the creator to 50 years beyond his or her life.

– if the creator is a corporation or business, up to 75 years after publication or 100 years following creation, whichever is shorter.

Copyright

Public domain images can be manipulated and used without permission from the artist and without having to pay the artist any royalties for using them

Fair use policy - instruction/education exclusions

Copyright Summary

The only time you can alter or manipulate images is if:– you receive permission from the original artist– you create the image yourself– the image is clearly public domain– the image is being used strictly for instructional

purposes in an educational setting

Example