Computer Graphics Bitmap v Vector Graphics

Learning Objectives: By the end of this topic you should be able to:

Learning Objectives: By the end of this topic you should be able to: describe the difference between Vector and Bitmap graphics describe the difference between Vector and Bitmap graphics

Learning Objectives: By the end of this topic you should be able to: describe the difference between Vector and Bitmap graphics describe the difference between Vector and Bitmap graphics evaluate their suitability for given applications evaluate their suitability for given applications

Bitmap v Vector Graphics

Features of Bitmap Graphics photographic imagesphotographic images ‒ usually produced by scanner or digital camera images stored as pixelsimages stored as pixels ‒ ‘dots’ on the screen higher number of pixels = better resolution (quality)higher number of pixels = better resolution (quality) subtle changes can be made to an imagesubtle changes can be made to an image ‒ since each pixel is an individually addressable unit ‒ e.g. photo editing bitmap editing software:bitmap editing software: - Photoshop, Paint Shop Pro, Picasa, Paint, Fireworks ….

Bitmap Graphics Suitability: images can be of photographic quality images can be of photographic quality  images are not as precise as vector drawings  large amount of disk space taken up  large images take a long time to load, display & send images can be compressed images can be compressed - take up less storage space & take less time to send - e.g. JPEG image files  resizing images can cause distortion - pixellation

Vector Images Features: used in technical drawingsused in technical drawings –architectural, CAD, 3D modelling/animation object-basedobject-based –shapes: line, circle, rectangle …… created by mathematical equationscreated by mathematical equations –points described by a relative distance from the origin lines/shapes described by features:lines/shapes described by features: –length, thickness, colour … vector editing software:vector editing software: - e.g. CorelDraw, AutoCAD, Flash, Fireworks, Illustrator, Freehand, ….

Vector Images Suitability: more accurate drawings can be made more accurate drawings can be made objects can be resized without losing clarity objects can be resized without losing clarity images take up less memory and less disk space images take up less memory and less disk space 3D images can be created 3D images can be created  more powerful computer required - software needs to recalculate when redrawing/zooming - greater demand on CPU  can’t display photographic images

Question An architect has the choice between saving his plans as a vector or a bitmap graphic. Giving reasons, identify which he should use.[4]

Exam Questions