Chapter 8 - Intro to Multimedia

8/4/2019 Chapter 8 - Intro to Multimedia

http://slidepdf.com/reader/full/chapter-8-intro-to-multimedia 1/46

CHAPTER 8Introduction to Multimedia

1



Introduction to

Multimedia

Part 1: Understanding

Multimedia

2



What is Multimedia

Multimedia = Multi + media

• Multi = many

• Media = medium or means by whichinformation is stored, transmitted,presented or perceived.

3



What is Multimedia

• By simple definition: Multimedia canbe any combination of text, graphics,audio, animation and video, to

effectively communicate ideas tousers.

4



What is Multimedia:

Definition 1“Multimedia is any

combination of text,

graphic art, sound,animation and videodelivered to users by

computer or otherelectronic means.”

TayVaughan

Multimedia : Making it work 5th Ed.

5



What is Multimedia:

Definition 2“Multimedia is the presentation of a(usually interactive) computerapplication, incorporating media

elements such as text, graphics,video, animation and sound oncomputer.”

Stephen McGloughinMultimedia: Concepts & practice

6



Types of MultimediaPresentation

• Linear Multimedia – Users have very little control over the

presentation; stand alone.

– Sample

• Interactive Multimedia –

Users dictate the flow of delivery. – Sample

7

http://www.swidigital.com/WebDesignTemplates/templates/FlashSamples/swidigital.cfm

http://www.adobe.com/devnet/flash/sample_files/html/movement_buttons.html

http://www.adobe.com/devnet/flash/sample_files/html/movement_buttons.html

http://www.swidigital.com/WebDesignTemplates/templates/FlashSamples/swidigital.cfm



Linear Multimedia

– The users sit back and watches thepresentation.

– The presentation normally playsfrom the start to end or even loopscontinually to present theinformation.

–A movie is a common type of linear multimedia.

8



Interactive Multimedia

– The users control the delivery of elements – tocontrol the what and when.

– Users have the ability to move around or followdifferent path through the informationpresentation.

– Advantage: complex domain of information canbe presented.

– Disadvantage: users might lost in the massive“information highway”.

– Useful for: information archive (encyclopedia),education, training and entertainment.

9



Introduction to

Multimedia

Part 2: Multimedia System

Characteristics

10



Multimedia SystemCharacteristics

• Multimedia systems must becomputer controlled.

• All multimedia components areintegrated.

• The interface to the final user maypermit interactivity .

• The information must be represented digitally .

11



Why representinformation in digital

form?• Storage

• Transmission

•Processing

12



Why representinformation in digital

form? – Digital representation permits the storage of different information types on the samedevices.

–Information may also be transmitted over asingle digital network.

– When digitized, all form of information maybe treated by computer programs, for

editing, quality improvement, orrecognition of the meaning of theinformation.

13



Part 3: Multimedia BuildingBlock

14

Introduction to

Multimedia



Multimedia Building

Block• Text

• Sound/Audio

•Image/Graphic

• Animation

• Video

15



Multimedia Building Block:

Text

16



Multimedia Building

Block: Text Text in Multimedia

– A key component of any multimediaproduct.

– Multimedia products depend on text forvarious reasons:

• Page title

•Content of the information

• Label and Instruction

17



Multimedia Building

Block: Text The power of meaning….

– Word must be chosen carefully

• Precise and accurate meaning to describe

what you mean

– Words appear in titles, menus andnavigational aids.

– Test the words that you plan to use onseveral users and observe theirreaction.

18



Multimedia Building

Block: Text Text Types Terminology

– Typeface: A family of similar charactersthat may include many sizes and styles

• ARIAL

• Courier

• Times New Roman

19



Multimedia Building


• Point: the font size is usually measured inpoint.

– A point is 1/72 of an inch (0.0138)

• Leading: the vertical space betweenlines of text

Line one

Line two

20

Leading



Multimedia Building


• Kerning: the space between twocharacters

• Adjusting the space between thecharacters is also called tracking

21



Multimedia Building

Block: TextSerif versus Sans Serif

• Serif type has extra stroke at certainpoints on letters. –

Serif fonts are considered to be more readableon printed pages.

– Times, Century Schoolbook, Bookman

• Sans serif type does not have those extra

strokes – Sans serif fonts are usually more readable oncomputer screens.

– Arial, Century Gothic

22




Sound/Audio

23



Multimedia BuildingBlock: Audio

Why is audio important inMultimedia?

• To reinforce message or theme

• To set the mood

• To catch the interest of the audience

• To alert the audience

• To include narration: effective fortraining and educational application.

24




Types of Audio

• 2 types of audio in multimedia – Music

• Background• Attention grabber

• etc..

– Speech (voice)• Narration

• Instruction

• etc

25




Audio Consideration

• While audio (music or narration) can bevery useful, most of the time, they can be

irritating as well. – Use appropriate music to reflect the moodor theme.

– Give the users choice of turning off/on theaudio.

– In cases where the content of a pagedepends on audio (speech), considerproviding transcript as the alternative. (fordeaf people, non multimedia pc)

26




The characteristics of audiowaves:

Audio is described in terms of two characteristics:

Frequency The rate at which audio is measured Number of cycles per second or Hertz (Hz) Determines the pitch of the sound as heard by our

ears

The higher frequency, the clearer and sharper thesound the higher pitch of sound

Amplitude (or loudness) Sound’s intensity or loudness The louder the sound, the larger amplitude.

27



Variation of frequencyand amplitude

28




Images

29



Multimedia BuildingBlock: Images

Before you create image…

• Plan your approach• Brainstorm ideas and concepts

for the graphic look

• Put the ideas on paper: makeflowchart and simulate thepages.

• Organize your tools• Make sure all tools needed are

available

30




2-D Drawing

• Still images are drawn in oneof two ways: – Bitmapped images

– Vector-drawn images

• Images are usually

compressed to save space – Formats like GIF, JPEG and

PNG incorporate compression

31




Bitmapped Image

• A simple matrix or grid of dotswith color information.

i.e. an array of color dots that whenlooked at from distance forms animage.

• The smallest element of a

bitmap is a pixel.

32

A pixel




Vector Image• Image data are stored in the

form of

– Data points that describe thecollection of lines, curves, circle,ellipses, text, polygon and othershape

– The characteristic of each shapesuch as line type and fill/shadingspecification

• The information of the images

can be stored as coordinates 33




Bitmapped vs. Vectorimages

• Vector images are easily scaledwithout quality loss.

• Bitmapped images get grainyand pixilated when zoomed in

34





• Vector image files are usually

smaller – Contain information on how to

recreate the image

– Vector graphics are web

friendly• Calculation time for vector

images can draw resources

–

Slow screen refresh rate– 35





• Vector image can easily be

edited. – Each element of the image retain its

identity and can be edited as anobject because the position and

attributes of each object are storedin the image model.

• Special effect can easily beapplied on bitmapped image

(distortion, blurring). 36




Animation

37



Multimedia BuildingBlock: Animation

The power of animation• Animation is achieved by

adding motion to stillimage/object.

• May also be defined as thecreation of moving pictures oneframe at a time.

• Animation grabs attention.• Few types of animation

– Layout transition

–

Process/ information transition– 38




Layout Transition• The simplest form of

animation is transition.

Spiral

Stretch

Zoom

Checkerboard

39




Process / InformationTransition

• Animation can be used to

describe complexinformation / process in aneasier way

– Perform visual cues (e.g. howthings work)

40




How animation works?Animation is possible because of

• a biological phenomenon known

as persistence of vision – An object seen by human eye

remains chemically mapped on theeye’s retina for a brief time afterviewing

• a psychological phenomenoncalled phi.

– Human’s mind need to conceptually

complete the perceived action i.e.41




How animation works?• Combination of these two (persistence

of vision + phi) make it possible for aseries of images that are changed very

slightly and very rapidly, one afteranother, to seemingly blend togetherinto a visual illusion of movement.

• E.g. a few cells or frames of rotating

logo, when continuously and rapidlychanged, the arrow of the compass isperceived to be spinning.

42




How animation works?Still images are flashed insequence to provide the

illusion of animation

43




Video

44

l i di ildi



Multimedia BuildingBlock: Video

Video consideration• Video can add great impact to

your multimedia presentationdue to its ability to draw people

attention.• Video is also very hardware-

intensive (requires the highestperformance demand on your

computer) – Storage issue: full-screen,

uncompressed video uses over 20megabytes per second (MBps) of

bandwidth and storage space. – 45

M l i di B ildi



Multimedia BuildingBlock: Video

Analog vs. Digital Video• Digital video is beginning to

replace analog in bothprofessional (production house

and broadcast station) andconsumer video markets.

• Digital video offer superiorquality at a given cost.

• Why? – Digital video reduces generational

losses suffered by analog video.

– Digital mastering means that quality

Documents

Chapter 8 - Intro to Multimedia