graphics, video, animation. use of good graphics, animation and video impacts on the effectiveness...

Graphics, Video, Animation

• Use of good graphics, animation and video impacts on the effectiveness of the multimedia application.

• The creation of good quality computer graphics, animation and video can be both difficult and time consuming.

• Make the most of the graphics capabilities of the host computer and the tools that are available for production of material.

Graphics

• Fundamental to multimedia

• Pictures, drawings, diagrams, charts, graphs, photographs, paintings, cartoons or maps

• Research has proved effectiveness and importance of graphics in teaching and learning

Graphics - negative aspects

• Poor use of graphics can interfere with learning process

• Avoid using graphics gratuitously

• Avoid inclusion of too many graphics

Graphics - How they help

• attracting learner attention

• directing learner action

• illustrating quantifiable constructs

• representing concrete objects

• representing abstract concepts

• simplifying complex information

• Pictures are easily remembered

• Remembered better than textual information

Graphics - cultural issues

• Useful for cross-cultural instruction

• E.g. Reduce the size and number of editions of documents by fewer changes of written language

• reduce translation cost

• ease learning by reducing ambiguity and increasing memorability

• Be aware that non-verbal information is very much culturally determined

• Don’t assume that graphics mean the same thing or are interpreted in same way across cultures

• Downplay or disguise cultural or national differences

• Replace realistic graphics with simplified ones.

• Be wary of using religious or mythological symbols animals national emblems cartoons

Graphics - Types

• Bit-mapped (often called sprites)

• Object based (often called vector graphics)

Bitmaps• excellent for photo-realistic images

• reasonably fast display time

• easily scanned in

• scalable, but definition usually lost unless carried out in editing software

• editable but can be difficult

• highly inefficient in disc storage (large file sizes)

• uncompressed file sizes depends on colour resolution of the image

• e.g. 640x480x16 colours (4 bits) = 150 000 bytes

• 640x480x256 colours (8 bits) = 300 000 bytes

• 640x480x32k colours (16 bits) = 600 000 bytes

• variety of image formats (PCX, TIF, GIF, BMP, JPEG, PICT etc)

Object Based• 2-D/3-D drawings

• poor realistic images

• display time can sometimes be slow – depending on complexity of drawing

• not easily scanned in

• scalable with no loss of definition

• editable

• highly efficient in disc storage

• file size generally independent of colour resolution

General points• Authorware has its own very simple

and limited object-based graphics editor for use only within Authorware applications.

• Majority of multimedia authoring tools use only bit-mapped images and many support only a limited number of image formats

• Not all formats are cross platform It can be a minefield!

• Good bit-map image editing software should be capable of importing & exporting a wide range of bit-map images

• Also provide a wide range of image editing/manipulation features (e.g. scaling, rotation, cutting, pasting, colour touching, brightening, darkening, sharpening etc.)

• Digital Video- (full motion, digitised images (films tv programmes etc.)

• Video is comparatively expensive and difficult to develop

• Only use when it serves a specific purpose or enhances the likelihood of learning

Video - Advantages

• Portrayal of concepts using motion the alteration of space and time the observation of dangerous processes in

a safe environment dramatisation of historical or complex

events demonstration of sequential processes the

viewer can review

Video - types of applications

• Clips of video

• Streamed video

• Navigable (virtual reality) video

Video - conversion

• Digitising

• reducing colours

• choosing frame rate

• sizing windows

• compression

Video - formats

• Audio Visual Interleave/AVI – Microsoft (PC)• QuickTime (QT,MOV) – Apple (MAC/PC)• MPEG – Platform independent /scaleable

/highly compressed• M-JPEG – Platform independent /scaleable

/highly compressed• DVI – Intel/IBM proprietary system

• Need specialist hardware/software to create/edit/view files

- video capture boards- file compression software to reduce file sizes- runtime software required to display files

(AVI/QT)- hardware decompression board/software

(MPEG/M-JPEG)

• Need acres of disc storage to capture/edit video

• 30 seconds of uncompressed video at 160x120x16-bit colour can occupy 15-30 MB of storage

• 1 minute of compressed video at 160x120x16-bit colour can occupy 10 Mb of storage

• Example video editing/splicing software

Adobe Premiere (MAC/PC)Digital Video Producer (PC)Avid Media Suite (MAC)Final Cut Pro (Mac)Final Cut Express (Mac)iMovie (MAC)

Animation

• Animation– Graphics may be simple, static images, simple moving images, or complex animated images

• Can also be achieved by changing the position of an object or sprite on Screen, to create illusion of movement

(e.g. motion icon in Authorware uses this technique)

• Use only when it is consistent with the learning task

• The influence of animation on learners is subtle

• Computer-based animation may be used to attract attention as much as it is to provide direct instruction

• Formats as for digital video

• Specialist software and hardware also needed

Types of Digital animation

• Frame-based animation - creating a series of individual cells

• Morphing - transforms the form of one object smoothly into another form

• 3-D animation - create objects that are more realistic in form and that appear to move through three dimensional space