1. October 2001Sheffield Hallam University1 Raster Graphics Raster formats used for storing digitized photographs, scanned artwork. comprised of individual pixels As a rule, higher resolutions deliver greater accuracy Large files take longer to transmit, print and process Common formats include TIFF, JPEG, GIF, PCX, & BMP. Adobe Photoshop, Picture Publisher, and Fractal Painter are among the most popular packages for creating raster graphics.

2. October 2001Sheffield Hallam University2 Vector Graphics Vector graphics are assembled using geometric primitives such as polygons, polylines, curves, circles, rectangles, etc. Unlike raster graphics, where resolution is pre-determined, vector graphics are resolution independent. In other words, image quality is directly related to the capability of your printer or output device.

3. October 2001Sheffield Hallam University3 Vector Graphics An advantage of this approach is that you can resize graphics without any fear of image degradation. A raster file can sometimes appear "coarse" or "jagged", depending on how the image is displayed. Vector graphics on the other hand look great under all conditions! Also known as ‘objects’

4. October 2001Sheffield Hallam University4 Vector Graphics When blown up, the raster file reveals what are commonly known as the "Jaggies"

5. October 2001Sheffield Hallam University5 3D Modelling Using computer graphics to represent all three dimensions Models can be rotated, stretched, viewed from many angles Used for ‘walk-throughs’ or simulations Used for movie and TV special effects

6. October 2001Sheffield Hallam University6 CAD / CAM 3D Modelling used for Computer-Aided Design and Computer-Aided Manufacture Physical properties can be simulated –Weight, volume, centre of gravity Products can be ‘manufactured’ on screen Production machines can be controlled by networked computers

7. October 2001Sheffield Hallam University7 Presentation Graphics Using computer graphics as visual aids Training, lectures, sales presentations Animated images Incorporated in multimedia presentations Easy to integrate various documents from other packages

8. October 2001Sheffield Hallam University8 Dynamic Media Can use computers to paint and draw Why not animate? Easier and quicker to produce sequences from still pictures than by hand Flash presentations

9. October 2001Sheffield Hallam University9 Digital Video Editing video tapes Splicing scenes, add transitions, create titles Video must be in digital form to edit Video digitiser converts analogue waves to digital data Modern digitisers use USB port for fast data transfer

10. October 2001Sheffield Hallam University10 Data Compression Digital video makes big demands on hardware Short video clips can occupy one CD- ROM Lossy data compression used to reduce storage requirement Loss of image quality

11. October 2001Sheffield Hallam University11 Hypertext Word processors give WYSIWYG Not always necessary if document not to be presented Dynamic, cross-referenced document Uses links Allows non-sequential navigation World Wide Web

12. October 2001Sheffield Hallam University12 Hypertext Can be disorienting Don’t always have the links you want Can’t scribble notes in the margin Many find screens harder to read than books

13. October 2001Sheffield Hallam University13 Multimedia Combination of text, graphics, animation, video, voice and sound effects to communicate Just like the evening news on TV! Computers allow interactive multimedia Will respond to user’s actions User can actively participate Good for training