MULTIMEDIA TECHNOLOGY

MULTIMEDIA TECHNOLOGY
CHAPTER ONE INTRODUCTION TO MULTIMEDIA SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

Objectives At the end of this chapter, students should be able to:
define basic terms and concepts related to multimedia technologies understand the history and evolution of media and multimedia technologies distinguish between the types of linear and non-linear multimedia systems state the four characteristics of multimedia system

History Of Multimedia What can we say about the evolution of media that has taken place for thousands of years? Since the dawn of time, people have had the need to communicate with one another This created what we called as communication media

Multimedia The notion of Multimedia Consists of two words:
Multi (Latin)= many; much; Medium (Latin) = An intervening substance through which something is transmitted or carried on.

What is Multimedia? Multimedia can be any combination of text, graphics, sound, animation and video, to effectively communicate ideas to users delivered by computer or any other electronic devices.

What is Multimedia? (Other definition)
‘Multimedia is any combination of text, art, sound, animation, and video. It is delivered to the user by electronic or digitally manipulated means. A multimedia project development requires creative, technical, organizational, and business skills.’ Tay Vaughan Multimedia : Making it work 7th Ed.

What is Multimedia? (Other definition)
‘“Multimedia is the presentation of a (usually interactive) computer application, incorporating media elements such as text, graphics, video, animation and sound on computer.” Stephen McGloughlin Multimedia: Concepts & Practice

Elements of Multimedia
Multimedia Building Block Digital environment USER Elements of Multimedia

Why Multimedia? Ease of use Intuitive Interface Immersive experience
Self-paced interaction and better retention Better understanding Cost effectiveness More fun = greater efficiency

Multimedia has a number of distinct and unique features, including:
Based on Edgar Dale (Cone Of Learning), on average, people remember: 10% of what they read, 20% of what they hear, 30% of what they see, 50% of what they hear and see,  multimedia approach multimedia rich elements, multi-sensory delivery system can facilitate greater retention of new knowledge

Types of Multimedia Linear Multimedia Nonlinear/Interactive Multimedia
Users have very little control over the presentation Nonlinear/Interactive Multimedia Users dictate the flow of delivery. User control the flow of the show.

Types of Multimedia: (1)Linear Multimedia
The users sit back and watches the presentation The presentation normally plays from the start to end or even loops continually to present the information. A movie is a common type of linear multimedia

Types of Multimedia: (2)Interactive Multimedia
The users control the delivery of elements – to control the what and when. Users have the ability to move around or follow different path through the information presentation. Advantage: complex domain of information can be presented. Disadvantage: users might lost in the massive “information highway”. Useful for: information archive (encyclopedia), education, training and entertainment.

What is a Multimedia Project?
The software vehicle, the messages, and the content together constitute a multimedia project. A multimedia project shipped to end-users with or without instructions is called a multimedia title. A project can also be launched on the Web. Authoring tools are used to merge multimedia elements into a project. These software tools are designed to manage individual multimedia elements and provide user interaction.

Delivering and Using Multimedia
The primary media for delivering multimedia projects are: Compact disc read-only (CD-ROM). Digital Versatile Disc (DVD) / Blu-ray Disc Multimedia Projects can also be delivered online (webs) and through PDAs/Hand-held Devices

Delivering and Using Multimedia : (1) CD-ROM
CD-ROM is the most cost-effective distribution medium for multimedia projects. It can contain up to 80 minutes of full-screen video or sound. CD burners are used for reading discs and converting the discs to audio, video, and data formats.

Delivering and Using Multimedia : (2) DVD / Blu-ray
Multilayered DVD technology increases the capacity of current optical technology to 18 GB. DVD authoring and integration software is used to create interactive front-end menus for films and games. DVD burners are used for reading discs and converting the disc to audio, video, and data formats. BD – Blu-ray disc (Blu-ray Disc Association BDA) next-generation format for high-definition video and high-density data. A single-layer disc can fit 23.3, 25, or 27 GB (enough for approximately four hours of high-definition video with audio) supports 25GB for one layer, 50GB for two and 100GB for four

Delivering and Using Multimedia (3) Online
Multimedia can be delivered online Copper wire, glass fiber, and radio/cellular technologies also serve a means for delivering multimedia files across a network Online uses include: Books and magazines, Education Movies, Entertainment News and weather Maps

Application of Multimedia
Business - Business applications for multimedia include presentations training, marketing, advertising, product demos, databases, catalogues, instant messaging, and networked communication. Schools - Educational software can be developed to enrich the learning process.

Application of Multimedia
Home - Most multimedia projects reach the homes via television sets or monitors with built-in user inputs. Public places - Multimedia will become available at stand-alone terminals or kiosks to provide information and help.

Multimedia Applications
Examples of Multimedia Applications: Digital video editing and production systems Electronic Newspapers/Magazines Games Groupware Home shopping Interactive TV Multimedia courseware Video conferencing Video-on-Demand (VoD) Virtual reality

Multimedia System Characteristics
Multimedia systems must be computer controlled. All multimedia components are integrated. The interface to the final user may permit interactivity. Information must be represented digitally.

Overlapping Technologies
Different branches of multimedia grow together because of new, upcoming multimedia technology and applications. Two challenges lie ahead: Timing requirements (synchronization etc.) Integration requirements (of different media types)

Summary Multimedia is the combination of text, graphics, sound, animation and video, to effectively communicate ideas to users delivered by computer. Multimedia projects can be linear or nonlinear. Multimedia projects are often stored on CD-ROM or DVDs. They can also be hosted on the Web. Multimedia is widely used in business, schools, public places, and at home.

References Vaughan Tay. Multimedia: Making It work. 7th Edition. McGraw Hill McGloughlin Stephen. Multimedia: Concepts and Practice. Prentice Hall

CHAPTER TWO THE MAKING OF MULTIMEDIA: AN INTRODUCTION
CGMB113: MULTIMEDIA TECHNOLOGY CHAPTER TWO THE MAKING OF MULTIMEDIA: AN INTRODUCTION SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

28 Objectives At the end of this chapter, students should be able to: Describe the four primary stages of a multimedia project Describe the skills and talents needed for a multimedia project Identify the most common hardware platforms and software tools for multimedia production and delivery

Stages of a Multimedia Project
Planning & Costing Designing & Producing Testing & Evaluating Delivering

Stages of a Multimedia Project : (1) Planning
Planning involve:- Developing an idea Identifying Objectives and Users Identify Skills and Resources Developing a graphic template, the structure, and a navigational system. Estimating Time and Cost Develop a small prototype or proof of concept

Stages of a Multimedia Project : (2) Design and Production
The planned tasks are performed to create a finished product. Task include storyboarding, designing a detail navigation structure, GUI consideration and HCI consideration. The product is revised, based on the continuous feedback received from the client by doing an evaluation.

Stages of a Multimedia Project : (3) Testing
The program is tested to ensure that it: meets the objectives of the project works on the proposed delivery platforms meets the client requirements.

Stages of a Multimedia Project : (4) Deliver
The final project is packaged and delivered to the end user.

Requirements for a Multimedia Project
Hardware Software Enabling Technology Creativity & Organizational Skills

Requirements for a Multimedia Project: (1) Hardware
Fast processor e.g. Pentium Large RAM (Random Access memory) Memory space that the computer uses when performing work. More RAMs means computer works quicker and more efficient. Storage Large Hard Disk Capable of supporting fast data transfer rate. Removable large-capacity storage devices E.g. rewritable CD-Rom, Zip drive A good CD-ROM burner & good CD-R software to complement it Easy CD Creature Deluxe

5. High resolution and a large monitor Minimum 17 inch monitor A dot-pitch value of .28 or smaller Dot-pitch: distance in millimetres between each of the red, green and blue dots etched into the phosphor of the inside of the screen. The smaller the dot-pitch value, the finer the image. Multisync monitor: allow the change in screen resolutions without having to reset the system.

6. Good video display card preferable capable of displaying 24 bit colours 7. Good video capture cards Allow you to capture video from a tape or camcorder 8. A good quality digital camera At least support 640 x 480 pixels images Has display panel Use disk or card to store the images before being uploaded to the computer. without having to reset the system.

9. Input devices Keyboard, mouse, track ball, touch screen, graphic tablet, data glove 10. A good flatbed scanner 24-bit colour depth and 300-dpi resolution 11. Colour Printer 12. Colour projector

Requirements for a Multimedia Project: (2) Software
Graphic design photo editing application Adobe Photoshop, Corel’s Photo-Paint 3D modeling and animation application Maya, 3D StudioMax Digital sound editing application Sonic Foundry’s Sound Forge Digital video editing application Adobe’s Premiere Multimedia authoring application Adobe Director Web page authoring/design tool Adobe Dreamweaver, Microsoft’s FrontPage

Requirements for a Multimedia Project: (3) Enabling Technology
Computing Power Increase in CPU processing power Increase in storage capacity Large capacity hardisk space – 500 Gigabytes (500 GB) to 1 Terabytes (1 TB) is common nowadays Increase in storage bandwidth e.g. disk array technology Personal computer and workstation revolution Progress in user interfaces and software concepts GUI, object-oriented concept and client-server paradigm

2. Data Networking Better transmission media Fiber optic as compared to copper wire Better transmission technique Fast packet switching Better services offered ATM, ISDN, B-ISDN, Broadband

3. Compression Technology GIF (Graphical Interchange Format) Mostly used with the internet JPEG (Joint Photographic Experts Group) Still image compression PNG (Portable network Graphic) Very popular nowadays especially for web-based application

3. Compression Technology MPEG (Motion Picture Expert Group) Full motion video compression MPEG-1 : for video & audio compression on digital storage media at 1.5Mbits/sec e.g. CD-ROM MPEG-2 : video & audio compression for high quality digital storage media (4 to 60Mbits/sec) and video service over communication network. MPEG-4 : complete audio-visual compression for a scene

Requirements for a Multimedia Project: (4) Creativity and Organizational skills.
In a multimedia project, being creative implies knowledge of hardware and software. It is essential to develop an organized outline detailing the skills, time, budget, tools and resources needed for the project Assets such as graphics, sound and the like should be continuously monitored throughout the project’s execution. A standardized file-naming procedure should be followed for precise organization and swift retrieval.

Summary The basic stages of a multimedia project are planning and costing, design and production, testing and delivery. Successful high-quality multimedia project requires a combination of talents and skills, not only on the artistic side but in organization, time and money. Trying to do it all, rather than building a good crew with appropriate skills, is tempting – but usually fatal. The most precious asset you can apply to a multimedia project is creativity – which is very difficult concept to learn Credit for a project is valuable commodity. Negotiate or make allowances for project credits early on.

Reference Vaughan Tay, Multimedia: Making It work. 7th Edition. McGraw Hill McGloughlin Stephen, Multimedia: Concepts and Practice. Prentice Hall F. Fluckiger, Understanding Networked Multimedia: Applications and Technology, Prentice Hall.

CGMB 113 / CITB123: MULTIMEDIA TECHNOLOGY
CHAPTER THREE THE PRODUCTION TEAM SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

48 48 Objectives At the end of this chapter, students should be able to: Understand the multimedia skill set and discuss how it applies to multimedia projects Define the skills needed to successfully manage a project team List the multimedia skill categories related to the information and interface of a project

Members of a Multimedia Team
A team of skilled individuals is required to create a good multimedia project. Team building refers to activities that help a group and its members function at optimum levels. The diverse range of skills required for a project is called the multimedia skillset.

Members of a Multimedia Team
A multimedia team consists of the following: Project manager. Multimedia designer. Interface designer. Writer. Video specialist Audio specialist. Multimedia programmer. Producer for the Web. Computer programmers.

Roles and Responsibilities in a Multimedia Team
The project manager is responsible for: The overall development, implementation, and day-to-day operations of the project. The design and management of a project. Understanding the strengths and limitations of hardware and software. Ensuring people skills and organizational skills. Conveying information between the team and the client.

Multimedia designer - This team consists of: Graphics designers, illustrators, animators, and image processing specialists who deal with visuals, thereby making the project appealing and aesthetic. Instructional designers, who make sure that the subject matter is presented clearly for the target audience.

Multimedia designer - This team consists of (continued): Interface designers, who devise the navigational pathways and content maps. Information designers, who structure content, determine user pathways and feedback, and select presentation media.

An interface designer is responsible for: Creating a software device that organizes content, allows users to access or modify content, and presents that content on the screen. Building a user-friendly interface.

A multimedia writer is responsible for: Creating characters, actions, point of view, and interactivity. Writing proposals and test screens. Scripting voice-overs and actors' narrations.

A video specialist needs to understand: The delivery of video files on CD, DVD, or the Web. How to shoot quality video. How to transfer the video footage to a computer. How to edit the footage down to a final product using digital nonlinear editing system (NLE).

An audio specialist is responsible for: Locating and selecting suitable music talent. Scheduling recording sessions. Digitizing and editing recorded material into computer files.

Multimedia programmer, also called a software engineer: Integrates all the multimedia elements into a seamless project, using authoring systems or programming language. Writes codes for the display of multimedia elements, and to control various peripheral devices. Manages timings, transitions, and record keeping.

Multimedia producer for the Web: Web site producers put together a coordinated set of pages for the Web. They also co-ordinate updates and changes.

Team Building Team members must be “team player”
Good communication and interpersonal skill are a must. Team building refers to activities that help the group and its member function at the best performance by creating a work culture incorporating the styles of its members.

Summary The diverse skills required to create a multimedia project is called the multimedia skillset. Team building refers to activities that help a group and its members function at optimum levels of performance. Roles and responsibilities are assigned to each team member in a multimedia project.

Reference Vaughan Tay, Multimedia: Making It work. 7th Edition. McGraw Hill

CGMB113/ CITB 123: MULTIMEDIA TECHNOLOGY
CHAPTER FOUR MULTIMEDIA PRODUCTION SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

64 64 64 Objectives At the end of this chapter, students should be able to: Recognize common issues involved in the process of developing multimedia project Determine the scope of a multimedia project Discuss the process and elements of a multimedia project Identify tools and techniques to overcome project management problems

The Multimedia Development Process (Issues)
Concept Validity Is this an idea that will sell?- important for Commercial product. Technology Dependence advance technology Availability of content can we fill the disk with relevant and useful content. Tool selection need to pick the best tool for the production.

The Multimedia Development Process (Issues)
Authoring to simplify the production process. Testing should be scheduled within the product development cycle. Delivery and product support Maintenance updated may be because- performance improvement, error correction or new content availability.

The Multimedia Project
MM project depend on three component. Producer - the creator of the product. Consumer - the sponsor. Product - including content , function and technology

Multimedia Development
Multimedia Development involves: Planning Requirement and Architecture Navigation Structure Storyboarding Content Production 6. Authoring 7. Prototyping 8. Evaluation 9. Testing 10. Deployment 11.Maintenance

(1) Planning Is the beginning phase of MM development and can make the difference in project success and failure. Planning will Define the project and product goal. What is the version of the product? Who will use it?. How will they benefit from it? Specify project objectives. Allocate personnel and equipment resources. Who and what will be involved in design, programming, testing and deployment of the product.

(1) Planning Scope and technical issue and content. What content, hardware and software are to be used to develop the product Determine schedule . How long will each major activities require? How long will subtasks take to complete? What are the critical dependencies between activities and tasks? Establish and monitor a project budget. Manage risks that would hinder the project

(1) Planning Fixed component describe the project, product, objective, and initial allocation of resources, schedule and budget. Dynamic component is tracking resources and project cost as the project unfolds.

(2) Requirement and Architecture
Defines and specifies the hardware and software required for a multimedia product. The requirement process specifies Program and hardware. Performance User interface. Hardware.

Hardware & software interfaces. Describe how the software to behave on the hardware platform. Requirement describe the expected behavior of the hardware and software and form the basis from which the architecture is designed.

Requirements analysis Architecture Design System Hardware and Software Planning Authoring Specification Platform

Some of the requirement of a MM product including Functional requirements User requirement Performance requirement The architecture transforms the requirements into a design by identifying or selecting Specific software including the application development environment and operating system. Specific hardware that supports the software How the software is installed onto the hardware How new software will be implemented to satisfy specific requirements

(3) Navigation Structure
Linear User navigate sequentially, from one frame to another Hierarchical User navigate along the branches of a tree structure that is shaped by the natural logic content. Non-Linear User navigate freely, unbound by predetermine routes Composite User can navigate freely, but occasionally some constraints occurs. Such as movies…

(3) Navigation Structure

(4) Storyboarding Storyboarding is the process of defining the message and describing user interaction with content and the application. Storyboarding involves a complex effort to develop panels for screen layouts that describe content, flow and format. A storyboard is a pictorial and/or written synopsis of text, graphics, videos, animations, etc. shown in the order they will appear in the finished presentation. In other words all multimedia resources are identified.

(4) Storyboarding

Carta Alir, Suara,Teks dan Video Teks, Grafik, Bunyi dan Animasi
Arahan Pengarangan Carta Alir, Suara,Teks dan Video Arahan Grafik Teks, Grafik, Bunyi dan Animasi Objek, / Carta ALir PAPAN CERITA-A T(Teks), G(Grafik), V(Video), B(Bunyi), S(Suara), A(Animasi) Muka Surat : 12 T1 : Kumpulan Intuitif T2 : “Sila klik pada gambar …” T3 : Kumpulan ini banyak T4 : Kumpulan ini sedikit G1: Gambar latar dengan dua gambar Qanitah G2 : Kotak ungu muda GK1 : Gambar 6 orang yang boleh diklik GK2 : Gambar 4 orang yang boleh diklik GP1 & GP2 : Ruang untuk meletakkan GH1-GH4 No. Papan Cerita : sbu1f1i1 (Ulangkaji / Penerangan) Topik : Multimedia Dalam Pendidikan(Kenal No 1-10) GK2 G1 T1 S1= T3 S2=T4 Mula Paparkan T1-T2, G1,G2, GK1-GK2 Papar T3 bunyikan S4 GK1 T2 G2 GP2 Papar T4 Bunyikan S4 Frame seterusnya GP1 Semak jawapan setelah pelajar klik ikon GK1 atau GK2 20

(5) Content Production Content production follows storyboarding so that the story ideas and concept can be turned into reality. Content defines the project information and material. Content can have low and high production value. The basic building blocks of content are films, videos, photographic collections, and textual information bases. Content can be either created or acquired.

(5) Content Production Acquiring content can be very expensive and time- consuming. Financial planning and allocation of sufficient time are important aspects of content acquisition. Pre-existing content can be obtained from a variety of sources. The sources from where pre-existing contents can be acquired are: Clip art collections - for simple and flexible content. Commercial stock houses - to ensure licensed work devoid of copyright infringements.

(5) Content Production Acquiring content can be very expensive and time- consuming. Financial planning and allocation of sufficient time are important aspects of content acquisition. Pre-existing content can be obtained from a variety of sources. The sources from where pre-existing contents can be acquired are: Clip art collections - for simple and flexible content. Commercial stock houses - to ensure licensed work devoid of copyright infringements. Photo, sound library, and stock footage house - for specific or complex content. The National Archives in Washington - for a rich source of content, both copyrighted as well as in the public domain.

(5) Content Production Rights must be required for using content
The rights should be licensed to use copyrighted material before a project is developed. Rights for unlimited use should be sought, as the content can be altered any time. When a work is created, certain rights are granted to its creator. An electronic right enables creators to publish work in a computer-based storage and delivery medium or on the Web.

(5) Content Production Public domain means either the work was never copyrighted or the expired copyright protection has not been renewed. Public domain material can be used freely without a license. Copyright protection applies to original works of authorship fixed in any tangible medium of expression. The owner's permission must be obtained before a work is used.

(5) Content Production Various rights management technologies are emerging and competing to become an industry standard. Any text or image that is copied or incorporated requires the permission of the owner. Such incorporated work is referred to as derivative work. It is important to obtain a written agreement from every individual contributing to the work. Developing projects includes designing interfaces, writing text, programming codes, and producing musical scores, sound effects, and video.

(6) Authoring Authoring is a process of assembling the content into the multimedia software development environment following the map provided by the storyboard Two kinds of authoring that occur Content assembly - the content is put together and linked to other content Functional programming - software is created to provide specific behavior

(6) Authoring Some issue in choosing tool
Level of interactivity required Platform requirement interaction with other software and system

(7) Prototyping Prototyping can be used to: Test product ideas
Evaluate Soft. Capabilities Evaluate design Strategies Test story lines Assess Content effectiveness

(7) Prototyping Planning System Hardware and Software Requirements
analysis Prototype development storyboarding Architecture Design Content production Authoring

(8) Evaluation Evaluation is the process that tests and assesses a MM product to make sure it is what was ordered and it does what it supposed to do. It starts the moment storyboards and requirements analysis activities begin. In-process evaluation that occurs during development, called formative evaluation Evaluation conducted following the authoring process is called summative evaluation.

(8) Evaluation Usability testing focuses on operation and performance of the product from the end user’s perspective. Usability testing may be applied to: Prototype versions of the product Data elements such as graphics, audio, video segment and animation clips.

(8) Evaluation storyboarding System Hardware and Software Content
production Requirements analysis Authoring Architecture Design Summative evaluation provides immediate feedback about the authoring activity to immediately correct problem Evaluation Formative evaluates throughout entire product development

(9) Testing Alpha testing - product is evaluated relatively early in the development phase, to review application concept, format, user interface, and page layout. Beta testing - product is evaluated prior to final release mainly to find bug and content mistake. Alpha testing is usually done in-house or with end users who agree to keep their comments and experiences confidential

(10) Deployment Releasing the product to the end user.
Task involve such as: Documentation for the product Mass production of CDROM Packing of product Marketing the product Mass production of hardware Installation of the software Training of personnel to use the software

(11) Maintenance The process in which a product can evolve and grow with emerging technology or to meet user demands. complete redistribution of the product Distribution of portions of the product maintenance activities may be accomplished a new development cycle for planning through authoring and evaluation. Documentation of old version is important.

Costing of a MM Production
Multimedia project cost based on Content cost Labor cost Equipment costs Talent and production cost Facility and location costs Marketing and production cost Maintenance and support costs Labor and content cost tend to be the highest single cost items.

Cost Modeling There are two basic models to follow when estimating costs Labor driven cost Cost/Content driven model Labor cost base on the amount of labor and time estimated for the project Estimate the number of hours for each labor category The key to this approach is knowing how much labor costs run and having a reasonable estimate of the overall product effort.

Content Modeling The content model is based on what it costs to create a single page and the cost per element content. This model assume that you can estimate number of pages and amount of content, example Number of pages for the entire product including page title, menus, content, help etc. A per page price can be assigned that account for design, programming, testing and management. Number of element of content. This may be measured as 100 words of text, a single graphic, or minutes of video.

Instructional Designer
Cost Analysis & Justification Rate of payment for multimedia project development (Example) Position Low Average High Producer 45 90 225 Manager 60 150 Content Specialist 105 Storyboard Artist Clerical Support 18 24 Graphic Artist Voice Talent 120 AV Specialist 75-225 Programmer 135 Instructional Designer 180 102 *IN Malaysian Ringgit / Hour

CHAPTER FIVE MULTIMEDIA BUILDING BLOCKS I TEXT SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

105 105 105 105 Objectives At the end of this chapter, students should be able to: Understand the history and development of text Understand the importance and significance of text in multimedia Identify the terms and concept related to text Describe the application of text in multimedia systems

Text in History Text came into use about 6,000 years ago
It was mainly used for vital information at the time (politics, taxes etc.) Ramesses the IVth offering Maat to Amon and Khonsou

Text in History Originated from Mesopotamia, Egypt, Sumeria and Babylonia Initially text was written in symbols such as pictographic signs and cuneiforms Johann Gensfleisch zum Gutenberg’s printing press revolutionized text in the 15th century

Importance of Text in a Multimedia Presentation
Words and symbols in any form, spoken or written, are the most common means of communication. Text is a vital element of multimedia menus, navigation systems, and content. Factors affecting legibility of text: Size Background and foreground color Style Leading

The power of meaning… Word must be chosen carefully
Precise and accurate meaning to describe what you mean Word must be chosen to illustrate to a few meaning Word appears in titles, menus and navigational aids. Test the words that you plan to use on several users and observe their reaction.

Understanding Fonts and Typefaces
Typeface: a family of similar characters that may include many sizes and styles ARIAL Courier Times Font: characters of a single size and style, which are part of the same font face family Arial – Arial Italic – Arial size 28 Arial Narrow Times – Times extra – Times bold Style: attributes of a font, such as italic, bold, underline, shadow etc.

The study of fonts and typefaces includes the following: Font styles Font sizes Cases. Serif versus Sans Serif Font styles include: Boldface Italic Underlining Outlining

Font size is measured in points. Character metrics are the general measurements applied to individual characters. Kerning is the spacing between character pairs. Leading is the space between lines. Line 1 Line 2 Leading

Cases A capitalized letter is referred to as 'uppercase', while a small letter is referred to as 'lowercase.' Placing an uppercase letter in the middle of a word is referred to as intercap.

Serif Vs Sans Serif Serif is the little decoration at the end of a letter stroke. Serif fonts are used for body text. Sans serif fonts do not have a serif at the end of a letter stroke. These fonts are used for headlines and bold statements.

Verdana is a sans serif type Times Roman is a serif type E E Times New Romans Verdana Serif Sans serif

Monospaced vs propotional fonts.
In a monospaced font, every character occupies the same amount of space horizontally, regardless of its shape. Text in monospaced font looks as if it was produced on a typewriter. Lucida typewrite is an example for monospaced font. In a proportional font, the space each letter occupies depends on the width of the letter shape. This produce a more even appearance, and you can fit more words in one line. Tahoma is an example for proportional font.

Measurement of Type The height of characters in a font is measured in points. One point being approximately 1/72 inch. The width is measured by pitch, which refers to how many characters can fit in an inch. Common pitch values are 10 and 12.

Issues when designing with text
Distinguish between display fonts and text fonts Display fonts: are designed for short pieces of text, such as headings, slogan or signs. They are not intended for use in lengthy passages. Are designed in fancy style. ( This is the example ) Text fonts: must be unobtrusive, so they do not intrude on the reader and interfere with the primary message of the text. Must easy to read, so they do not cause fatigue when they are read for hours at a time. Usually are fonts which are familiar to the users. (This is the example)

Boldface is intrusive, so reserve it for headings or similar use. Italic text, because of its slant, often render badly at low resolution, making it hard to read Consider legibility when choosing font can you read this? Or this word ? Is this too small? Or is this readable ? Avoid too many different faces

Strike the density balance Minimize lines of centered text Distinguish text link with colours and underlining Explore text colours and backgrounds Use distorted layout to grab attention

Adjust leading and kerning for readability. In text blocks, adjust the leading for the most pleasing spacing. Lines too tightly packed are difficult to read. Vary the size of the font in proportion to the importance of the message you are delivering. Remember that long continuous texts covering multiple pages are tiring to read. Always breakdown information into smaller chunk, and summaries them.

Use anti-aliased text: anti-aliasing blends the colours along the edges of the letters (called dithering) to create a soft transition between letter and its background. Anti-aliasing also smoothes jaggies at the edge of characters.

True type font: the same font will be used on the printer and the screen (as oppose to scalable printer resident font) True type : Arial, Times New Roman Scalable printer resident: Antique olive, CG Omega

Font compatibility: not all font is available on every operating system. Choose regularly used fonts such as Arial, Times New Roman, Courier If you want to use your own font, that font must be first installed.

Designing menu and icon
Menu: choose word with precise meaning Icon/symbols : choose icon which has very few meaning for interpretation, or go for something which is globally understood. Can be useful if language barrier is an issue Consider using text label together with icons.

Who wants to get an A ? Animating text
Animated text can grab attention Do not overdo it. Too many animation and attention grabbers will distract users attention. Who wants to get an A ?

Hypertext and Hypermedia
Hypermedia provides a structure of links through which a user can navigate and interact. Hypermedia structure: Hypermedia elements are called nodes Nodes are connected using links A linked points is called an anchor Hypertext words are linked to other elements Hypertext is usually searchable.

The final rule… Experiment your work by try and error.
Test your work with users – accept critique and improvise.

CHAPTER SEVEN MULTIMEDIA BUILDING BLOCKS III IMAGE SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

131 131 131 131 131 131 Objectives At the end of this chapter, students should be able to: identify various factors that apply to the use of images in multimedia describe the capabilities of bitmap and vector images define various aspects of 3D modeling cite the various file types used in multimedia describe the use of colors and palettes in multimedia

Before you create image…
11/26/2017 Before you create image… Plan your approach Brainstorm ideas and concepts for the graphic look Put the ideas on paper : make flowchart and simulate the pages. Organize your tools Make sure all tools needed are available Have multiple monitors, if possible, for lots of screen real estate.

2-D Drawing Still images are drawn in one of two ways:
Bitmapped images Vector-drawn images Images are usually compressed to save space Formats like GIF, JPEG and PNG incorporate compression

Bitmapped Image Pixel A simple matrix or grid of dots with color information. i.e. an array of color dots that when looked at from distance forms an image. The smallest element of a bitmap is a pixel Zoom-in A pixel

Bitmapped Image Computer combines red, blue and green (RGB) colors
Each pixel is associated with bit depth. Bit depth determines the number of possible color. 1-bit 2 colors 4-bit 16 colors 8-bit 256 colors 24-bit 16,777,216 colors (16 million

Create on your own using software tools
Bitmapped Image How do we obtained bitmap images? Source of image Stock Photos Photo CDs Clip Art Print Screen - Video cam - Camera - Scanner Capture using Create on your own using software tools

Vector Image Image data are stored in the form of
Data points that describe the collection of lines, curves, circle, ellipses, text, polygon and other shape The characteristic of each shape such as line type and fill/shading specification The information of the images can be stored as coordinates The computer recreates the image based on the information describing the image.

Vector image Vector images are defined using formulas. Resize 10 times
i.e. RECT 0,0,200,200,RED,BLUE Resize 10 times 10x = 1200 x 800 1x = 120 x 80

Bitmapped vs Vector images
Vector images are easily scaled without quality loss. Bitmapped images get grainy and pixilated when zoomed in

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 Bitmaps are more suitable for large images with many different colors (photograph)

Vector image require plug-ins Vector image can easily be edited. Each element of the image retain its identity and can be edited as an object because the position and attributes of each object are stored in the image model. Special effect can easily be applied on bitmapped image (distortion, blurring). To apply the same effect, vector image need to be transformed to bitmapped first.

3-D Drawing 3-D image can be drawn on a 2-D surface by creating depth perception. The depth of a 3-D image is calculated as the z dimension Y is the height X is the width Z is the depth.

3-D Drawing 3-D drawing software support features such as:
Directional lighting Motion Different perspective

Perspective views in 3D

3-D Drawing A 3-D object combines various shapes such as blocks, cylinders, spheres or cones (described using mathematical formulas or constructs)

3-D Drawing Shape can be extruded….
Extrude extends the shape of plane surface some distance, either perpendicular to the shape itself, or along the defined line

3-D Drawing ….. or lathed When an object is lathed, the profile of the object is rotated around the defined axis to create the 3-D object.

3-D Drawing A 3-D scene consist of various objects arranged in a 3-D space. Objects and elements in 3-D space have properties such as color, texture, location and so on. Lighting and camera views can be configured.

3-D Shadowing Shadows are created when object block the light from the light source. Ray Tracing is a process used to determine where every single ray of light goes after the ray leaves the light source. What the ray hits What the ray bounces off (reflection) What the ray is bent through (refraction)

3-D Shading Is a process in which the computer paints darker colours on the surfaces of an object that are farther away or obstructed from the light. Shading can be applied to provide a variety of effects. Flat shading is the easiest for the computer to render Gourand shading, Phong shading and Ray Tracing take longer to render but provides more realistic images.

A scene can use different types of shading
3-D Shading A scene can use different types of shading Gourand shading Ray tracing Flat shading Phong shading

3-D Image Rendering When modeling is complete, the final output must be rendered. Rendering is the process where the application calculates how the 3-D scene should look like given the objects, their position, their surface material, lighting option and so on and create the final output.

3-D Image Rendering Rendering is time and resource consuming.
Need fast processor and large RAM Final image for the animated movie Toy Story were rendered using 87 dual-processor 30 quad processor 100 MHz SPARCstation 20 46 days of continuous process to render the film’s 110, 000 frames, at the rate of one frame for every one to three hours.

Example on rendering – step 1
Background

Object

Object + Background

Panoramas QuickTime VR is used to view a single surrounding image.
Various images are stitched together to create a single panorama.

Image file formats Macintosh formats Windows formats
PICT format as a way to accommodate bitmaps and vector graphics. Windows formats PCX, TIFF, JPEG, GIF and PNG

Colors Quantum theory Atoms produces unique colors as light passes through Light travels in the form of photons, or quanta Color is the frequency of light wave The rainbow shows the spectrum of visible colors (ROYGBIV) Colors below the range are infrared Colors above the range are ultraviolet

Colors Light rays stimulate rods and cones in the eye’s retina
Receptors are sensitive to millions of combinations of red, green and blue light Color perception is further influenced by cultural meaning and associations of certain colors. Computerized color Computers combine red, green and blue (RGB) lights Bit depth determines the number of possible colors (also the size of the image)

The Visible-Color Spectrum Wheel
Printer color Is generated using the CMYK color model Cyan (C) Magenta (M) Yellow (Y) Black (K) The Visible-Color Spectrum Wheel

Color palette A palette is a mathematical table that defines colors
Also called a color look up table (CLUT) on Macintosh Palettes of 256 colors (8-bit color depth) provided in Adobe’s Director – for use on the web

Color palette The standard color palettes on a Macintosh and in Windows differ slightly 216 colors of the standard 256-color palettes are common to both computer systems. 8-bit system -> 256-value system Optimal palette: a small range of color is chosen to best suit the color range of the image.

Color resolution/bit-depth
the number of different colors any one pixel can display. Gray-scale images = 256 colors (also called 8-bit color) to define all the shades of gray. Instead, 65,500 colors (16-bit color) or 16.8 million colors (24-bit True Color) will provide significantly more color depth and help retain the original photograph's qualities. Nearly all stock-photo libraries, whether on CD or online, provide images in 24-bit color.

Color resolution/bit-depth
1-bit color = 2 colors: monochrome, black and white 2-bit color = 4 colors: gray-scale 3-bit color = 8 colors 4-bit color = 16 colors 8-bit color = 256 colors 12-bit color = 4096 colors 16-bit color = 65,536 colors 24-bit color = True color or 16,777,216 mixed colors (Red 256 × Green 256 × Blue 256)

Original image in JPG format, 23K
Dithering Dithering is where colors that are not in the current palette are converted to the nearest color. Forcing 24-bit image into 8-bit display adapter Image quality is compromised. For example, dithering is required to display a full-color image on older computers that have only a 256-color graphics card because those computers must simulate colors they can't actually display. 256 web-safe colors, 100% dither, 21K

Resizing and Resampling
Resizing and Resampling both refers to creating a different-sized image from the original. Resizing simply expands or contracts the image to the new required size May introduce interference patterns Resampling rebuilds a new pixel pattern for the same image using the new required size Produce more even and smother image

Conventional Cameras The basic technology that makes cameras work is fairly simple. A still film camera is made of three basic elements: an optical element (the lens), a chemical element (the film) and a mechanical element (the camera body itself). The only trick to photography is calibrating and combining these elements in such a way that they record a crisp, recognizable image.

Digital Camera – A filmless Camera
Instead of film, a digital camera has a sensor that converts light into electrical charges. The image sensor employed by most digital cameras is a charge coupled device (CCD). Some cameras use Complementary Metal Oxide Semiconductor (CMOS) or Foveon X3 Image Sensor technology instead. All these CCD, CMOS and Foveon X3 image sensors convert light into electrons A CCD image sensor A CMOS image sensor

What Goes On Inside a Digital Camera

Reference Vaughan Tay, Multimedia: Making It work. 7th Edition. McGraw Hill S. McGloughlin, “Multimedia: Concept and Practice”, Prentice Hall, 2001

CHAPTER EIGHT MULTIMEDIA BUILDING BLOCKS IV ANIMATION SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

173 173 173 173 173 173 173 Objectives At the end of this chapter, students should be able to: identify the terms and concept related to animation describe how animation can be used in multimedia systems understand some of the common animation techniques

Introduction to Animation
To animate can be thought of as, “to bring to life” Animation = An illusion of movement created by sequentially playing still image frames with different movements at the general rate of fps (frames per second) Animation = rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement.

A little bit of history The earliest form of animation is a 5,200 year old earthen bowl found in Iran in Shahr-i Sokhta which has five images painted along the sides. When the bowl is spun, it shows a goat leaping up to a tree to take a pear. Early examples of attempts to capture the phenomenon of motion drawing can be found in paleolithic cave paintings, where animals are depicted with multiple legs in superimposed positions, clearly attempting to convey the perception of motion

How Animation Works Animation is achieved by adding motion to still image/object. May also be defined as the creation of moving pictures one frame at a time. Few types of animation Layout transition Process/ information transition Object movement This animation moves at 10 frames per second. This animation moves at 2 frames per second. At this rate, the individual frames should be discernible

Introduction to Animation
Animation is possible because of a biological phenomenon known as persistence of vision An object seen by human eye remains chemically mapped on the eye’s retina for a brief time after viewing a psychological phenomenon called phi Human’s mind need to conceptually complete the perceived action i.e. translating the action

How Animation Works Combination of these two (persistence of vision + phi) make it possible for a series of images that are changed very slightly and very rapidly, one after another, to seemingly blend together into a visual illusion of movement. E.g. a few cells or frames of rotating logo, when continuously and rapidly changed, the arrow of the compass is perceived to be spinning. Still images are flashed in sequence to provide the illusion of animation

How Animation Works Still images are flashed in sequence to provide the illusion of animation

How Animation Works The speed of the image changes is called the frame rate. Film is typically delivered at 24 frames per second (fps) In reality, the projector light flashes twice per frame, thus increasing the flicker rate to 48 times per second to remove any flicker effect. The more interruptions per second, the more continuous the beam of light appears, the smoother the animation.

Traditional Animation Types and Techniques
Cel animation - The animation artist draws or paints on sheets of celluloid film. The cels are layered over the background, then photographed frame by frame. Stop-motion animation. Stop-motion animation is a film technique that involves shooting one frame of film at a time. A stationary camera is pointed at the object or scene. Each frame of motion picture film is exposed individually. Between exposures, the object or scene is manipulated or changed. Rotoscoping - is the technique of re- drawing live-action images on paper in order to capture natural motion in one's illustrations. "The Lost World", 1925, animation by Willis O'Brien, one of the early masters of stop-motion.

Animation Technique: Cel Animation
Made famous by Disney A series of progressively different graphics are used for each frame of film Elements in a scene that might move, for example Kluang man, are drawn on sheets of transparent material called ‘cel’, and laid over a background which is drawn separately (kampung scenery for example) In producing a sequence, only the moving elements on the cel need to be redrawn for each frame, the fixed part of the scene need only be made once.

Animation Technique: Cel Animation
Animation is drawn between keyframes. Key frames identify the start and end of some action The process of filling in the action is called tweening. Tweening is a process which requires calculating the number of frames between keyframes and the path the action takes, and then actually sketching on to a cel the series of progressively different outlines.

Animation Techniques - Cel Animation
This image shows how two transparent cells, each with a different character drawn on them, and an opaque background are photographed together to form the composite image.

Animation Technique: Stop Motion
Miniatures three-dimensional sets are used (stage, objects) Objects are moved carefully between shots. Objects may include articulate figures, whose limbs can be repositioned, or solid figures whose parts are replaced, or substitute between shots, to produce an effect of gesture, walking, and so on. Plasticine may be used for objects, to be manipulated between shots to produce both natural movement, and otherwise impossible changes and transformations.

Stop-motion animation

Computer Animation – Digital cel & sprite animation
Employ the same logic and procedural concept of cel animation. Objects are drawn using 3D modeling software Objects and background are drawn on different layers, which can be put on top of one another. Layers allow you to create separate parts of a still image, for example, a person and the background of a scene they are walking through – so that each can be altered or moved independently.

Computer Animation – Digital cel & sprite animation
Sprite animation – animation on moving object (sprite). A set of images, called faces is associated with each sprite. Example, a walking man, can be created by advancing the position of the sprite (the man) and cycling through the faces (walking motion), the man can be made to walk.

Computer Animation – Key Frame Animation
Keyframes : Are drawn to provide the pose a detailed characteristic of characters at important points in the animation. Example, specify the start and end of a walk, the top and bottom of the fall. 3D modeling and animation software will do the tweening process It fill in the gaps between the keyframes and create a smooth animation. You just set the value of frames per second (fps) for your animation.

Animation Techniques – Claymation And Computer Animation
Example of a claymation Example of a computer animation

Basic Concepts of Tweening

Computer Animation – Hybrid Animation
Mixing cel and 3D computer animation. May as well include life footage.

Animation Techniques - Kinematics
The study of motion of jointed structure (such as people) Realistic animation of such movement can be complex. Latest technology use motion capture for complex movement animation. Inverse kinematics is the process of linking objects, and defining their relationship and limits.

Animation Techniques - Morphing
The process of transitioning from one image to another When morphing, few key elements (such as a nose from both images) are set to share the same location (one the final image).

Animation File Formats
Windows Media files : .avi, .asf or .wmv Apple QuickTime files: .qt or .mov Motion video files : .mpeg or .mpg Flash files : .swf Shockwaves files : .dcr Animated GIF : .gif

Creating Animation Use digital camera to capture each drawn frame.
Scan the drawn image/frame. Video camera (connected through video capture card) is connected directly to computer to capture each frame of animation on disk – let it be on paper, cel, constructed on 3D set or by any other techniques discussed. Software tool can help create object

References Vaughan Tay, Multimedia: Making It work. 7th Edition. McGraw Hill S. McGloughlin, “Multimedia: Concept and Practice”, Prentice Hall, 2001

CHAPTER NINE MULTIMEDIA BUILDING BLOCKS V VIDEO SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

199 199 199 199 199 199 199 199 Objectives At the end of this chapter, students should be able to: identify the terms and concept related to video state the advantages and disadvantages of analog and digital video describe the color models used in video describe how video can be used in multimedia systems

Basics of Video Video is an excellent tool for delivering multimedia.
Video places the highest performance demand on computer and its memory and storage. Digital video has replaced analog as the method of choice for making and delivering video for multimedia.

Analog vs. Digital Video
Digital video is beginning to replace analog in both professional (production house and broadcast station) and consumer video markets. Digital video offer superior quality at a given cost. Why? Digital video reduces generational losses suffered by analog video. Digital mastering means that quality will never be an issue

Analog vs. Digital Video
Analog video is represented as a continuous (time varying) signal. Digital video is represented as a sequence of digital images. Analog is linear, must rewind/forward to go to frame Digital offers superior quality Digital does not experience generational loss

With a video-capture card, you can capture analog video from a VCR or camcorder and convert the analog video into a digital format PCI Video capture card USB Video capture card Television Camcorder VCR

How video works Video basics
Light passes through the camera lens and is converted to an electronic signal by a Charge Coupled Device (CCD) Most consumer-grade cameras have a single CCD. Professional–grade cameras have three CCDs, one for each Red, Green and Blue color information.

How video works Video basics
The output of the CCD is processed by the camera into a signal containing three channels of color information and synchronization pulse (sync). If each channel of color information is transmitted as a separate signal on its own conductor, the signal output is called RGB, which is the preferred method for higher- quality and professional video work.

How video works Transmission mode
Composite video transmits the whole signal in a single cable (all three color information and the sync signals are mixed together). Yield less precise color definition Colors cannot be manipulated or corrected A coaxial cable or RCA connector are usually used. S-Video separates color and brightness information over two wires. S-Video cables use a unique S-Video connector.

How video works Transmission mode
Component video separates color (chrominance) and brightness (luminance) information over three wires. Two chrominance and one luminance signals Chrominance = information on colors Luminance = information on brightness Luminance and chrominance are used to encode color during transmission.

Video Cables Composite Video (RCA) Component Video S-Video

HDMI Cable The High-Definition Multimedia Interface (HDMI) is a licensable compact audio/video connector interface for transmitting uncompressed digital streams. HDMI connects DRM (digital right management)- enforcing digital audio/video sources such as a set-top box, an HD DVD disc player, a Blu-ray Disc player, a personal computer, a video game console, or an AV receiver to a compatible digital audio device and/or video monitor such as a digital television (DTV). HDMI began to appear in 2006 on consumer HDTV camcorders and high-end digital still cameras

How video works interlaced video
Video frames for television are interlaced Each frame consist of two separate fields : odd and even fields. The technique of mixing the two fields together to create one image is called interlacing. interlaced video

How video works Video is recorded onto magnetic tapes (analog)
Audio is recorded on a separate straight-line track at the top of the videotape. At the bottom of the tape is a control track containing the pulses used to regulate speed.

Diagram of tape path across the video head for analog recording

Diagram of tape path across the video head for digital recording

Color encoding for video transmission
1. RGB signal Consist of separate signals for red, green and blue Other colors can be coded as a combination of these primary colors e.g. white = R + G + B

Color encoding for video transmission
2. YUV signal Separate brightness (luminance) component Y Color information (3 chrominance signals U and V) Y = 0.3R G B U = (B-Y) * 0.493 V = (R-Y) * 0.877 3. Composite signal Individual component (RGB, YUV or YIQ) must be combine into one signal.

Broadcast Video Standards
NTSC North America, South America, Japan 525 interlaced resolution lines 30 frames per second (fps) PAL Australia, South Africa, Europe 625 interlaced resolution lines 25 frames per second (fps)

Broadcast Video Standards
HDTV (High Definition Television) Six HDTV formats exist Resolution vary from 720 to 1080 lines Frame rates vary from 24 to 60 fps. Format can either be interlaced or progressively scanned. The aspect ratio of HDTV is 16:9 Aspect ratio for NTSC, PAL, SECAM and computer monitor is 4:3 The aspect ration of 16:9 is sometimes called “widescreen”

Broadcast video standard
4:3 aspect ratio 16:9 aspect ratio

Broadcast video standard
SECAM (Sequential Color and Memory) This standard is used in France, Russia and a few other countries. SECAM video has 625 interlaced lines of resolution.

Integrating Computers and Televisions for Video
We will look at: Differences between computer and television video Overscan and safe title area Video color Interlaced and progressive scanning Interlacing effect Working with text and titles

Differences between computer and television video
1. Overscan and the safe title area Every analog TV displays the picture differently Common practice for the television industry to broadcast an image larger than the the standard TV screen so that the “edge” seen by viewer is always bounded by the TV’s physical frame, or bezel. This is called overscan

In contrast, Computer monitor displays a smaller image (underscan), leaving a black border inside the bezel. When a digitized video image is displayed on the RGB screen, there is a border around the image, and when computer screen is converted to video, the outer edges of the images will not fit on a TV screen.

It is advisable to scale the video within the “safe title area” as shown below so that the image will not be affected by over scanning.

2. Video color Computer monitors uses RGB color. Video uses YUV color. A YUV signal includes separate red, blue and luminance (brightness) information. Many RGB colors will not display in the YUV color space. High-end video editing applications offer filters to help you identify and correct ‘illegal’ RGB colors in the YUV color space.

3. Interlaced and progressive scanning Television uses interlaced scanning Computer employs progressive scanning

4. Interlacing effect Lines that are one pixel thick will flicker on a TV due to interlacing. Make sure fonts and other lines are thicker than one pixel.

Working with text and titles.
Use plain, sans serif fonts Use light text over a dark background Do not kern the letters too tight Remember to avoid single-pixel-thick lines. Avoid parallel lines, boxes, and tight concentric lines Keep the graphics and title within the title safe area Leave titles on screen long enough to be read

Shooting and Editing Video
1. Shooting platform Use steady shooting platform to avoid shaky camera work. Use a tripod or place the camera on a stable platform If must shoot handheld, use a camera that has an electronic image stabilization feature for static shoot such as “steady-cam” balancing attachment.

2. Lighting Lighting can make a major different between amateur and professional shooting Always strive for adequate lighting A standard studio lighting arrangement includes Fill Key Rim background

The “Lighting Lab” software

3. Blue Screen Blue screen key editing is used to superimposed subjects over different backgrounds. Blue screen is popular because expensive sets are not required. The blue background color will be replaced by the background image, frame by frame. e.g. Star Trek movie.

The following figure shows frames taken from a video of an actor shot against blue screen on a commercial stage. The blue background was removed from each frame, and the actor himself was turn into a photo- realistic animation that walked and jumped over the computer desktop.

4. Composition Consider the delivery medium when composing shots For playback from CD-ROM or the web in small computer window, avoid wide panoramic shots. Use close-up or head-and-shoulder shooting. Consider the amount of motion in shot The more scene changes from frame to frame, the more “information” need to be transferred from the computer memory to the screen, unless you have a very good compression algorithm to handle this. Keep the camera still, let the subject move, not the camera.

Optimizing video for CD-ROM
CDs are cheap and widely supported Data rates are slow Capacity is limited to 700 MB Limit audio-video synchronization Use a CD-ROM friendly codec, such as Cinepak Use a smaller playback screen Optimize the video

Video Compression Compression is necessary when working with video on computers. Compression is performed by a compression/decompression scheme called a codec. Uncompressed digital video has a data rate of approximately 20 MBps. Many computer hard drives cannot handle this data rate.

USING VIDEO Video places the highest performance demand on the computer and it’s memory compared to all other multimedia elements Video Conferencing USAGES Video Surveillance Video Streaming For Web Sites Video Presentation

Applying Video In MM Systems
Video is used for practically everything people wish (and would pay) to see, including sci-fi, fantasy, adventure, horror and sex.

Reference Vaughan Tay, Multimedia: Making It work. 7th Edition. McGraw Hill S. McGloughlin, “Multimedia: Concept and Practice”, Prentice Hall, 2001

CHAPTER TEN THE CD FAMILY SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

241 241 241 241 241 241 241 241 Objectives At the end of this chapter, students should be able to: understand the history and evolution of compact disc technologies define basic terms and concepts related to compact disc technologies Describe the CD, CD-R and CD-RW technologies and how it works

CD HISTORY 1937: A. Reeves invents pulse code modulation (PCM), a technology used by computers and CD's for audio in the present day H. Aiken from Harvard approaches IBM and proposes a electrical computing machine. 1950: Richard W. Hamming publishes information about error detection/correction codes. It would be impossible for CD's to work without error correction. 1958: Invention of the Laser Stereo LP's produced Integrated Circuit introduced by Texas Instruments 1960: Working Laser produced

CD HISTORY 1969: Klass Compaan, a Dutch physicist comes up with the idea for the Compact Disc. 1970: At Philips, Compaan and Pete Kramer complete a glass disc prototype and determine that a laser will be needed to read the information. 1972: Compaan and Kramer produce color prototype of this new compact disc technology

CD HISTORY 1978: Philips releases the video disc player, Philips proposes that a worldwide standard be set. Polygram (division of Philips) determined that polycarbonate would be the best material for the CD. Decision made for data on a CD to start on the inside and spiral towards the outer edge. Disc diameter originally set at 115mm. Type of laser selected for CD Players. 1979: Sony & Philips compromise on the standard sampling rate of a CD kHz (44,100 samples per second) Disc diameter changed to 120mm to allow for 74 minutes of 16-bit stereo sound with a sample rate of 44.1 kHz

CD HISTORY 1980: Compact Disc standard proposed by Philips & Sony.
1981: Digital Audio Disc Committee also accepts Compact Disc Standard. 1982: Sony & Philips both have product ready to go. Compact Disc Technology is introduced to Europe and Japan in the fall. 1983: Compact Disc Technology is introduced in the United States in the spring. CD-ROM Prototypes shown to public 30,000 Players & 800,000 CD's sold in the U.S : Second Generation & Car CD players introduced.

CD HISTORY 1985: Third generation CD Players released. CD-ROM drives hit the computer market. 1986: CD-I (Interactive CD) concept created. 3 Million Players & 53 Million CD's sold in U.S. 1987: Video CD format created. 1988: CD-Recordable Disc/Recorder Technology Introduced 1990 – 92 : 28% of all U.S. households have CD's. 9.2 million players & 288 million CD's sold annually in the United States. World Sales close to 1 Billion. CD-I format achieved. CD-Recordable Introduced to the Market. "QuickTopix" the first CD-R pre-mastering Software introduced by Allen Adkins. CD-R Sales reach 200,000

HOW CD WORKS CDs and DVDs are everywhere these days.
Whether they are used to hold music, data or computer software, they have become the standard medium for distributing large quantities of information in a reliable package.

HOW CD WORKS: Material A CD is a fairly simple piece of plastic, about four one-hundredths (4/100) of an inch (1.2 mm) thick. Most of a CD consists of an injection-molded piece of clear polycarbonate plastic. During manufacturing, this plastic is impressed with microscopic bumps arranged as a single, continuous, extremely long spiral track of data. Once the clear piece of polycarbonate is formed, a thin, reflective aluminum layer is sputtered onto the disc, covering the bumps. Then a thin acrylic layer is sprayed over the aluminum to protect it. The label is then printed onto the acrylic. A cross section of a complete CD (not to scale) looks like this:

HOW CD WORKS: The Spiral
CD has a single spiral track of data, circling from the inside of the disc to the outside. The fact that the spiral track starts at the center means that the CD can be smaller than 4.8 inches (12 cm). What the picture below shows you is how incredibly small the data track is. It is approximately 0.5 microns wide, with 1.6 microns separating one track from the next. (A micron is a millionth of a meter.) And the bumps are even more miniscule...

HOW CD WORKS: Bumps The elongated bumps that make up the track are each 0.5 microns wide, a minimum of 0.83 microns long and 125 nanometers high. (A nanometer is a billionth of a meter.) Looking through the polycarbonate layer at the bumps, they look something like this:

HOW CD WORKS: Bumps You will often read about "pits" on a CD instead of bumps. They appear as pits on the aluminum side, but on the side the laser reads from, they are bumps. The incredibly small dimensions of the bumps make the spiral track on a CD extremely long. If you could lift the data track off a CD and stretch it out into a straight line, it would be 0.5 microns wide and almost 3.5 miles (5 km) long! To read something this small you need an incredibly precise disc-reading mechanism.

HOW CD WORKS: Pit and Land
Standard CD-ROM 120mm in diameter, 1.2mm thick, hole 15mm across in center Data is represented by a spiral of small pits, coated with a reflective metal layer, coated with a protective lacquer Pits are 0-12m deep and about 0.6 m wide, neighbouring turns of the spiral are 1.6 m apart, giving a track density of tpi

HOW CD WORKS: Pit and Land
The transition from pit to land and from land to pit corresponds to a coding of 1 in the digital data stream, 0 is no transition. Land Pit

CD Player Components The CD player has the job of finding and reading the data stored as bumps on the CD. Considering how small the bumps are, the CD player is an exceptionally precise piece of equipment. The drive consists of three fundamental components: A drive motor spins the disc. This drive motor is precisely controlled to rotate between 200 and 500 rpm depending on which track is being read. A laser and a lens system focus in on and read the bumps. A tracking mechanism moves the laser assembly so that the laser's beam can follow the spiral track. The tracking system has to be able to move the laser at micron resolutions.

CD Player Components

What the CD Player Does: Laser Focus
The fundamental job of the CD player is to focus the laser on the track of bumps. The laser beam passes through the polycarbonate layer, reflects off the aluminum layer and hits an opto-electronic device that detects changes in light. The bumps reflect light differently than the "lands" (the rest of the aluminum layer), and the opto-electronic sensor detects that change in reflectivity. The electronics in the drive interpret the changes in reflectivity in order to read the bits that make up the bytes

What the CD Player Does: Tracking
The hardest part is keeping the laser beam centered on the data track. This centering is the job of the tracking system. The tracking system, as it plays the CD, has to continually move the laser outward. As the laser moves outward from the center of the disc, the bumps move past the laser faster – This happens because the linear, or tangential, speed of the bumps is equal to the radius times the speed at which the disc is revolving (rpm). Therefore, as the laser moves outward, the spindle motor must slow the speed of the CD. That way, the bumps travel past the laser at a constant speed, and the data comes off the disc at a constant rate.

RECORDING Recording process is called mastering
waveform carrying the encoded information is transferred to a modulator, controlling a powerful short-wavelength laser beam as it passes through a lens, forming a spot on the photo-resist coating of a glass master disc. Physical negative “stampers” are then developed from the glass master.

CD Burners In 1999, 2000 and early 2001, sales of CD burners and blank CD-Recordable discs skyrocketed. Today, writable CD drives (CD burners) are standard equipment in new PCs, and more and more audio enthusiasts are adding separate CD burners to their stereo systems

Writing CDs CD-Rs, don't have any bumps or flat areas at all. Instead, they have a smooth reflective metal layer, which rests on top of a layer of photosensitive dye. When the disc is blank, the dye is translucent: Light can shine through and reflect off the metal surface. But when you heat the dye layer with concentrated light of a particular frequency and intensity, the dye turns opaque: It darkens to the point that light can't pass through.

Writing CDs By selectively darkening particular points along the CD track, and leaving other areas of dye translucent, you can create a digital pattern that a standard CD player can read. The light from the player's laser beam will only bounce back to the sensor when the dye is left translucent, in the same way that it will only bounce back from the flat areas of a conventional CD. A CD burner's job, of course, is to "burn" the digital pattern onto a blank CD.

Burning CD: Laser Assembly
The CD burner has a moving laser assembly, just like an ordinary CD player. But in addition to the standard "read laser," it has a "write laser." The write laser is more powerful than the read laser, so it interacts with the disc differently: It alters the surface instead of just bouncing light off it. Read lasers are not intense enough to darken the dye material, so simply playing a CD- R in a CD drive will not destroy any encoded information. Inside the CD burner

Burning CDs: Write Laser
The write laser moves outward while the disc spins. The bottom plastic layer has grooves pre-pressed into it, to guide the laser along the correct path. By calibrating the rate of spin with the movement of the laser assembly, the burner keeps the laser running along the track at a constant rate of speed. To record the data, the burner simply turns the laser writer on and off in synch with the pattern of 1s and 0s. The laser darkens the material to encode a 0 and leaves it translucent to encode a 1.

The machinery in a CD burner looks pretty much the same as the machinery in any CD player. There is a mechanism that spins the disc and another mechanism that slides the laser assembly.

Most CD burners can create CDs at multiple speeds. At 1x speed, the CD spins at about the same rate as it does when the player is reading it. This means it would take you about 60 minutes to record 60 minutes of music. At 2x speed, it would take you about half an hour to record 60 minutes, and so on. For faster burning speeds, you need more advanced laser- control systems and a faster connection between the computer and the burner. You also need a blank disc that is designed to record information at this speed.

The main advantage of CD-R discs is that they work in almost all CD players and CD-ROMS, which are among the most prevalent media players today. In addition to this wide compatibility, CD-Rs are relatively inexpensive. The main drawback of the format is that you can't reuse the discs. Once you've burned in the digital pattern, it can't be erased and re-written.

CD-RWs CD-rewritable discs, commonly called CD-RWs
CD-RW discs have taken the idea of writable CDs a step further, building in an erase function so you can record over old data you don't need anymore. These discs are based on phase-change technology.

CD-RWs: Phase-change Compounds
In CD-RW discs, the phase-change element is a chemical compound of silver, antimony, tellurium and indium. As with any physical material, you can change this compound's form by heating it to certain temperatures. When the compound is heated above its melting temperature (around 600 degrees Celsius), it becomes a liquid; at its crystallization temperature (around 200 degrees Celsius), it turns into a solid

CD-RWs : Phase-change Compounds
In the compound used in CD-RW discs, the crystalline form is translucent while the amorphous fluid form will absorb most light. To encode information on the disc, the CD burner uses its write laser, which is powerful enough to heat the compound to its melting temperature. These "melted" spots serve the same purpose as the bumps on a conventional CD and the opaque spots on a CD-R: They block the "read" laser so it won't reflect off the metal layer. Each non-reflective area indicates a 0 in the digital code. Every spot that remains crystalline is still reflective, indicating a 1.

The Erase Laser As with CD-Rs, the read laser does not have enough power to change the state of the material in the recording layer -- it's a lot weaker than the write laser. The erase laser falls somewhere in between: While it isn't strong enough to melt the material, it does have the necessary intensity to heat the material to the crystallization point. By holding the material at this temperature, the erase laser restores the compound to its crystalline state, effectively erasing the encoded 0. This clears the disc so new data can be encoded.

CD-RWs: Conclusion CD-RW discs do not reflect as much light as older CD formats, so they cannot be read by most older CD players and CD-ROM drives. Some newer drives and players, including all CD-RW writers, can adjust the read laser to work with different CD formats. But since CD-RWs will not work on many CD players, these are not a good choice for music CDs. For the most part, they are used as back-up storage devices for computer files.

References Pohlmann, Ken C. "The Compact Disc Handbook, 2nd Edition" Copyright 1992 & 1989 A-R Editions, Inc. Copyright 1999, Jeremy Despain OneOff, Inc. 2000, 2001 OneOff Media, Inc. History of CD Marshall Brain, How CD Works, Tom Harris, How CD_Burners Works,

CHAPTER ELEVEN THE DVD FAMILY SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

274 274 274 274 274 274 274 274 274 Objectives At the end of this chapter, students should be able to: understand the history and evolution of digital video disc (DVD) and Blu-ray technologies define basic terms and concepts related to digital video disc (DVD) and Blu-ray technologies Describe the DVD and Blu-ray technologies and how it works

DVD HISTORY 1996: DVD Technology Introduced. Prices of Recorders and CD-R Media go down significantly. High Demands cause World-Wide CD-R Media Shortage. 1997: DVD Released. DVD Players/Movies hit consumer market. DVD-R standard created (3.9 Gig). 1998: DVD-RAM, DVD-Recordable systems/equipment hits market. DVD-Video/ROM authoring tools hits the market. CD-R prices continue to drop. 1999: DVD-Video Becomes main stream. Consumers begin purchasing DVD Players & Movies on a mass level. Most major film studios have titles on DVD. DIVX Dies (DIgital Video eXpress). Second Generation DVD Burners. 4.7 Gig DVD-R Media Developed.

DVD: THE BASICs The first DVD player hit the market in March 1997.
A DVD has a much larger data capacity. Holds about seven times more data than a CD does. Typical contents of a DVD movie: Up to 133 minutes of high-resolution video with 720 dots of horizontal resolution (The video compression ratio is typically 40:1 using MPEG-2 compression.) Soundtrack presented in up to eight languages using 5.1 channel Dolby digital surround sound Subtitles in up to 32 languages DVD can also be used to store almost eight hours of CD-quality music per side

DVD Advantage Better picture quality
DVD movies have an on-screen index. And go to one scene to another with the remote, no need to rewind or fast-forward. DVD players are compatible with audio CDs. DVD movies may have several soundtracks on them, and they may provide subtitles in different languages.

Storing Data in DVD Like CD, data on a DVD is encoded in the form of small pits and bumps in the track of the disc. A DVD is composed of several layers of plastic, totaling about 1.2 millimeters thick. Each layer is created by injection molding polycarbonate plastic. This process forms a disc that has microscopic bumps arranged as a single, continuous and extremely long spiral track of data

Storing Data in DVD Once the clear pieces of polycarbonate are formed, a thin reflective layer is sputtered onto the disc, covering the bumps. Aluminum is used behind the inner layers, but a semi- reflective gold layer is used for the outer layers, allowing the laser to focus through the outer and onto the inner layers. After all of the layers are made, each one is coated with lacquer, squeezed together and cured under infrared light. For single-sided discs, the label is silk-screened onto the nonreadable side. Double-sided discs are printed only on the nonreadable area near the hole in the middle (refer to picture on next slide)

DVD Formats Cross sections of the various types of completed DVDs (not to scale)

Single Layer DVD has a spiral track of data
the track always circles from the inside of the disc to the outside. That the spiral track starts at the center means that a single-layer DVD can be smaller than 12 centimeters if desired. Data tracks on a DVD

Single Sided DVD The data track is incredibly tiny -- just 740 nanometers separate one track from the next (a nanometer is a billionth of a meter). And the elongated bumps that make up the track are each 320 nanometers wide, a minimum of 400 nanometers long and 120 nanometers high. (see next slide for illustration)

DVD Pit Layout

Single Sided DVD You will often read about "pits" on a DVD instead of bumps. They appear as pits on the aluminum side, but on the side that the laser reads from, they are bumps. The microscopic dimensions of the bumps make the spiral track on a DVD extremely long. If you could lift the data track off a single layer of a DVD, and stretch it out into a straight line, it would be almost 7.5 miles long To read bumps this small you need an incredibly precise disc-reading mechanism

DVD vs CD DVDs can store more data than CDs for a few reasons:
Higher-density data storage Less overhead, more area Multi-layer storage

Double_Layer DVD The technique for double-layering a DVD disc is of particular importance: outer layer is semi-transparent [18-30% reflectivity] inner layer is more reflective [50-80% reflectivity] pickup lens is refocused to read desired layer extra lead-out space required on inner layer two methods of writing the layers Parallel track path (PTP) Opposite track path (OTP) - allows near continuous read

DVD vs CD Higher Density Data Storage
Single-sided, single-layer DVDs can store about seven times more data than CDs A large part of this increase comes from the pits and tracks being smaller on DVDs. Specification CD DVD Track Pitch 1600 nanometers 740 Minimum Pit Length (single-layer DVD) 830 nanometers 400 nanometers Minimum Pit Length (double-layer DVD) 440 nanometers

DVD vs CD Less Overhead, More Area
DVD format doesn't waste as much space on error correction, enabling it to store much more real information. Another way that DVDs achieve higher capacity is by encoding data onto a slightly larger area of the disc than is done on a CD

DVD vs CD Multi-Layer Storage
To increase the storage capacity even more, a DVD can have up to four layers, two on each side. The laser that reads the disc can actually focus on the second layer through the first layer. Format Capacity Approx. Movie Time Single-sided/single-layer 4.38 GB 2 hours Single-sided/double-layer 7.95 GB 4 hours Double-sided/single-layer 8.75 GB 4.5 hours Double-sided/double-layer 15.9 GB Over 8 hours

The DVD Player A DVD player is very similar to a CD player. It has a laser assembly that shines the laser beam onto the surface of the disc to read the pattern of bumps. Considering how small the bumps are, the DVD player has to be an exceptionally precise piece of equipment.

The DVD Player The drive consists of three fundamental components:
A drive motor to spin the disc - The drive motor is precisely controlled to rotate between 200 and 500 rpm, depending on which track is being read. A laser and a lens system to focus in on the bumps and read them - The light from this laser has a smaller wavelength (640 nanometers) than the light from the laser in a CD player (780 nanometers), which allows the DVD laser to focus on the smaller DVD pits. A tracking mechanism that can move the laser assembly so the laser beam can follow the spiral track - The tracking system has to be able to move the laser at micron resolutions.

Other DVD DVD-R DVD-RW DVD-Audio

Blu-Ray Discs Blu-ray Discs (BD) has high storage capacity
Can hold and playback large quantities of high- definition video and audio, as well as photos, data and other digital content The Blu-ray name is a combination of "blue," for the color of the laser that is used, and "ray," for optical ray. The "e" in "blue" was purposefully left off, according to the manufacturers, because an everyday word cannot be trademarked. Photo courtesy Blu-ray Disc Association

What is a Blu-ray Disc? A current, single-sided, standard DVD can hold 4.7 GB (gigabytes) of information. That's about the size of an average two-hour, standard-definition movie with a few extra features. But a high-definition movie, which has a much clearer image takes up about five times more bandwidth and therefore requires a disc with about five times more storage. As TV sets and movie studios make the move to high definition, consumers are going to need playback systems with a lot more storage capacity. Blu-ray is the next-generation digital video disc. It can record, store and play back high-definition video and digital audio, as well as computer data

What is a Blu-ray Disc? Photo courtesy Blu-ray Disc Association BD-ROM disc researcher

Blu-ray Advantages Record high-definition television (HDTV) without any quality loss Provide interactivity Instantly skip to any spot on the disc Record one program while watching another on the disc Create playlists Edit or reorder programs recorded on the disc Automatically search for an empty space on the disc to avoid recording over a program Access the Web to download subtitles and other extra features

Blu-ray vs DVD A single-layer Blu-ray disc,
can hold up to 27 GB of data two hours of high-definition video 13 hours of standard video. A double-layer Blu-ray disc 54 GB of data, 4.5 hours of high-definition video more than 20 hours of standard video.

Blu-ray vs DVD

How Does Blu-ray Work? DVDs, se a red laser to read and write data. Blu-ray uses a blue laser (which is where the format gets its name). A blue laser has a shorter wavelength (405 nanometers) than a red laser (650 nanometers). The smaller beam focuses more precisely, enabling it to read information recorded in pits that are only 0.15 microns (µm) (1 micron = 10-6 meters) long -- this is more than twice as small as the pits on a DVD. Plus, Blu-ray has reduced the track pitch from 0.74 microns to microns

How Does Blu-ray Work? The smaller the pits (and therefore the bumps), the more precise the reading laser must be. The smaller pits, smaller beam and shorter track pitch together enable a single-layer Blu-ray disc to hold more than 25 GB of information -- about five times the amount of information that can be stored on a DVD.

DVD Vs Blu-Ray Construction
Source: Blu-ray Disc Association

Reference OneOff Media, Inc. History of CD. 2000, 2001
Karim Nice, How DVDs Works, Stephanie Watson, How Blu-ray Works, Lachlan L. Mackinnon. Notes: Multimedia Technology (F291G2). Heriot_Watt University. Edinburgh. Scotland

CHAPTER TWELVE DISPLAY TECHNOLOGY (I) CRT & LCD SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

identify the terms and concept related to display technology
At the end of this chapter, students should be able to: identify the terms and concept related to display technology state the different types of display technologies understand how the various display technology works

CRT TECHNOLOGY 100 year old technology.
all TVs in use today rely on a device known as the cathode ray tube, or CRT, to display their images 100 year old technology. A glass bell envelope which contains a vacuum and an electron gun. By the application of electric current, and electron stream is created, which is fired through the vacuum towards the inside face of the glass envelope. Here it strikes a phosphor layer, which converts the beam into visible light, colour being achieved through mixing varying levels of light intensity from red, green and blue phosphors.

CRT TECHNOLOGY There is a cathode and a pair (or more) of anodes.
There is the phosphor-coated screen. There is a conductive coating inside the tube to soak up the electrons that pile up at the screen-end of the tube. However, in the diagram 1.1, you can see no way to "steer" the beam -- the beam will always land in a tiny dot right in the center of the screen Steering coils are use to position the electron beam at any point on the screen.

CRT TECHNOLOGY ( diagram 1.1)

CRT TECHNOLOGY: Cathode
The "cathode" is a heated filament The heated filament is in a vacuum created inside a glass "tube." The "ray" is a stream of electrons that naturally pour off a heated cathode into the vacuum. Electrons are negative. The anode is positive, so it attracts the electrons pouring off the cathode. In a TV's cathode ray tube, the stream of electrons is focused by a focusing anode into a tight beam and then accelerated by an accelerating anode. This tight, high-speed beam of electrons flies through the vacuum in the tube and hits the flat screen at the other end of the tube. This screen is coated with phosphor, which glows when struck by the beam.

CRT TECHNOLOGY: Steering Coils
steering coils are simply copper windings These coils are able to create magnetic fields inside the tube, and the electron beam responds to the fields. One set of coils creates a magnetic field that moves the electron beam vertically, while another set moves the beam horizontally. By controlling the voltages in the coils, you can position the electron beam at any point on the screen.

CRT TECHNOLOGY: Steering Coils

CRT TECHNOLOGY: Phosphor
Phosphor is any material that, when exposed to radiation, emits visible light. The radiation might be ultraviolet light or a beam of electrons. Any fluorescent color is really a phosphor. Fluorescent colors absorb invisible ultraviolet light and emit visible light at a characteristic color.

CRT TECHNOLOGY: Phosphor
In a CRT, phosphor coats the inside of the screen. When the electron beam strikes the phosphor, it makes the screen glow. In a color screen, there are three phosphors arranged as dots or stripes that emit red, green and blue light. There are also three electron beams to illuminate the three different colors together. There are thousands of different phosphors that have been formulated. They are characterized by their emission color and the length of time emission lasts after they are excited.

CRT TECHNOLOGY: Adding Color
The screen is coated with red, green and blue phosphors arranged in dots or stripes If you turn on your TV or computer monitor and look closely at the screen with a magnifying glass, you will be able to see the dots or stripes. On the inside of the tube, very close to the phosphor coating, there is a thin metal screen called a shadow mask. This mask is perforated with very small holes that are aligned with the phosphor dots (or stripes) on the screen

When a color TV needs to create a red dot, it fires the red beam at the red phosphor. Similarly for green and blue dots. To create a white dot, red, green and blue beams are fired simultaneously -- the three colors mix together to create white. To create a black dot, all three beams are turned off as they scan past the dot. All other colors on a TV screen are combinations of red, green and blue.

CRT TECHNOLOGY: Painting the Screen
In a black-and-white TV, the screen is coated with white phosphor and the electron beam "paints" an image onto the screen by moving the electron beam across the phosphor a line at a time. To "paint" the entire screen, electronic circuits inside the TV use the magnetic coils to move the electron beam in a "raster scan" pattern across and down the screen. The beam paints one line across the screen from left to right. It then quickly flies back to the left side, moves down slightly and paints another horizontal line

The term horizontal retrace is used to refer to the beam moving back to the left at the end of each line, while the term vertical retrace refers to its movement from bottom to top. A TV screen normally has about 480 lines visible from top to bottom

Standard TV uses Interlacing technique when painting the screen The beam paints every other line as it moves down the screen -- for example, every odd-numbered line. Then, the next time it moves down the screen it paints the even-numbered lines, alternating back and forth between even-numbered and odd- numbered lines on each pass. The entire screen, in two passes, is painted 30 times every second. Progressive scanning, which paints every line on the screen 60 times per second. (computer monitors use progressive scanning because it reduces flicker) Because the electron beam is painting all 525 lines 30 times per second, it paints a total of 15,750 lines per second. (Some people can actually hear this frequency as a very high-pitched sound emitted when the television is on.)

When a television station wants to broadcast a signal to your TV, or when your VCR wants to display the movie on a video tape on your TV, the signal needs to mesh with the electronics controlling the beam so that the TV can accurately paint the picture that the TV station or VCR sends. The TV station or VCR therefore sends a well-known signal to the TV that contains three different parts: Intensity information for the beam as it paints each line Horizontal-retrace signals to tell the TV when to move the beam back at the end of each line Vertical-retrace signals 60 times per second to move the beam from bottom-right to top-left

CRT: Advantage and disadvantage
Advantages of CRT robust, well-known technology high-quality resolution and image control Disadvantages of CRT size (footprint) on monitors short or mini-neck tubes possible, but exacerbates distortion problems analogue technology

LCD Technology Liquid Crystal Display (LCD)
LCDs are common because they offer some real advantages over other display technologies. They are thinner and lighter and draw much less power A simple LCD display from a calculator

Liquid Crystals So, do liquid crystals act like solids or liquids or something else? Liquid crystals are closer to a liquid state than a solid. It takes a fair amount of heat to change a suitable substance from a solid into a liquid crystal, and it only takes a little more heat to turn that same liquid crystal into a real liquid. This explains why liquid crystals are very sensitive to temperature and why they are used to make thermometers and mood rings. It also explains why a laptop computer display may act funny in cold weather or during a hot day at the beach!

Nematic Phase Liquid Crystals
The liquid crystals that make LCDs possible. Affected by electric current. LCDs use these liquid crystals because they react predictably to electric current in such a way as to control light passage.

Creating an LCD LCD is possible because Light can be polarized.
Liquid crystals can transmit and change polarized light. The structure of liquid crystals can be changed by electric current. There are transparent substances that can conduct electricity

Creating LCD LCD is made of several layers that are arranged according to the following order: Polarising filter Sheet of glass Electrode Alignment layer Liquid crystals Alignment layer, Electrode, Sheet of glass, Polarising filter.

Creating LCD

How LCD Works? The first stage of an LCD display involves passing the light through a polarizing filter. It then gets into a layer filled with liquid crystals that are controlled by the transistors. The light then passes through color filters (like CRT monitors, each LCD display pixel consists of three components – red, green and blue). Transistor applies voltage to liquid crystals, that sets their spatial alignment. Light changes its polarization angle when it passes through the ordered liquid crystal molecular structure, and depending on its new polarization angle it will be absorbed completely or partially. This allows the creation of any halftone from black to pure white.

Types of LCD Two types of LCD Passive Matrix (Dual Scan)
Active Matrix-TFT (Thin Film Transistor)

Passive Matrix (Dual Scan)
The matrix refers to the underlying layer of conductors, used to activate the screen elements. In passive matrix, this is usually made up of a lattice of conductive strips running from edge to edge of the display As these strips are relatively long, the time taken to activate each element is longer than in active matrix models. This means that it takes longer to refresh the screen, an effect that increases with the size of the screen and leads to submarining and the need to use mouse trails

Passive Matrix (Dual Scan)
To improve the performance of passive matrix, dual scan LCD splits the conductor matrix into two sections, each of which are addressed separately by drivers down both sides of the screen. Dual scan maintains the low power requirement of passive matrix but increases refresh rate, with the result that many contemporary notebook displays use this technology

Active Matrix-TFT (Thin Film Transistor)
Uses a much more complex conductor array, replacing the lattice with a grid of independent transistors that lie on a layer beneath the screen elements. Far more complex to manufacture, but much faster because it independently addresses the liquid crystal cells. Viewing angle is wider, as transistor position obstructs backlight less than conductor strips. Much more expensive and has a higher power drain.

Active Matrix-TFT (Thin Film Transistor)

Advantage n’ Disadvantage LCD
Advantages LCD monitors consume less power Do not produce electromagnetic radiation as CRTs do Do not flicker like CRTs Are light and slim in size Full viewable size Disadvantages More expensive than CRT (but less so now!) Poorer resolution

Reference Tom Harris, How LCDs Works, Lachlan L. Mackinnon. Notes: Multimedia Technology (F291G2). Heriot_Watt University. Edinburgh. Scotland

CHAPTER THIRTEEN DISPLAY TECHNOLOGY (II) PDP, & TOUCHSCREEN SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

identify the terms and concept related to display technology
At the end of this chapter, students should be able to: identify the terms and concept related to display technology state the different types of display technologies understand how the various display technology works

Plasma Display Panels Based on the principle that certain gases emit light when subject to an electric current The basic idea of a plasma display is to illuminate tiny colored fluorescent lights to form an image. Each pixel is made up of three fluorescent lights -- a red light, a green light and a blue light. Just like a CRT television, the plasma display varies the intensities of the different lights to produce a full range of colors.

What is Plasma? The central element in a fluorescent light is a plasma, a gas made up of free-flowing ions (electrically charged atoms) and electrons (negatively charged particles). In a plasma with an electrical current running through it, negatively charged particles are rushing toward the positively charged area of the plasma, and positively charged particles are rushing toward the negatively charged area.

What is Plasma? In this mad rush, particles are constantly bumping into each other. These collisions excite the gas atoms in the plasma, causing them to release photons of energy. Xenon and neon atoms, the atoms used in plasma screens, release light photons when they are excited. Mostly, these atoms release ultraviolet light photons, which are invisible to the human eye. But ultraviolet photons can be used to excite visible light photons.

What is Plasma?

Inside the Display: Gas and Electrodes
The xenon and neon gas in a plasma television is contained in hundreds of thousands of tiny cells positioned between two plates of glass. Long electrodes are also sandwiched between the glass plates, on both sides of the cells. The address electrodes sit behind the cells, along the rear glass plate. The transparent display electrodes, which are surrounded by an insulating dielectric material and covered by a magnesium oxide protective layer, are mounted above the cell, along the front glass plate.

Both sets of electrodes extend across the entire screen. The display electrodes are arranged in horizontal rows along the screen and the address electrodes are arranged in vertical columns. As you can see in the next diagram, the vertical and horizontal electrodes form a basic grid.

To ionize the gas in a particular cell, the plasma display's computer charges the electrodes that intersect at that cell. It does this thousands of times in a small fraction of a second, charging each cell in turn. When the intersecting electrodes are charged (with a voltage difference between them), an electric current flows through the gas in the cell. The current creates a rapid flow of charged particles, which stimulates the gas atoms to release ultraviolet photons

Inside the Display: Phosphors
The released ultraviolet photons interact with phosphor material coated on the inside wall of the cell. Phosphors are substances that give off light when they are exposed to other light. When an ultraviolet photon hits a phosphor atom in the cell, one of the phosphor's electrons jumps to a higher energy level and the atom heats up. When the electron falls back to its normal level, it releases energy in the form of a visible light photon

The phosphors in a plasma display give off colored light when they are excited. Every pixel is made up of three separate subpixel cells, each with different colored phosphors. One subpixel has a red light phosphor, one subpixel has a green light phosphor and one subpixel has a blue light phosphor. These colors blend together to create the overall color of the pixel. By varying the pulses of current flowing through the different cells, the control system can increase or decrease the intensity of each subpixel color to create hundreds of different combinations of red, green and blue. In this way, the control system can produce colors across the entire spectrum

The main advantage of plasma display technology is that you can produce a very wide screen using extremely thin materials. And because each pixel is lit individually, the image is very bright and looks good from almost every angle. The image quality isn't quite up to the standards of the best cathode ray tube sets, but it certainly meets most people's expectations. The biggest drawback of this technology has to be the price. In the near future, setting up a new TV might be as easy as hanging a picture!

TOUCHSCREEN A touchscreen is any monitor, based either on LCD (Liquid Crystal Display) or CRT (Cathode Ray Tube) technology, that accepts direct onscreen input. The ability for direct onscreen input is facilitated by an external (light pen) or an internal device (touch overlay and controller) that relays the X,Y coordinates to the computer.

How Touch Screen Work A basic touchscreen has three main components: a touch sensor, a controller, and a software driver. The touchscreen is an input device, so it needs to be combined with a display and a PC or other device to make a complete touch input system.

How Touch Screen Work Touch Sensor Controller Software Driver

How Touch Screen Work Touch Sensor
A touch screen sensor is a clear glass panel with a touch responsive surface. The touch sensor/panel is placed over a display screen so that the responsive area of the panel covers the viewable area of the video screen. There are several different touch sensor technologies on the market today, each using a different method to detect touch input. The sensor generally has an electrical current or signal going through it and touching the screen causes a voltage or signal change. This voltage change is used to determine the location of the touch to the screen.

How Touch Screen Work Controller
The controller is a small PC card that connects between the touch sensor and the PC. It takes information from the touch sensor and translates it into information that PC can understand. The controller is usually installed inside the monitor for integrated monitors or it is housed in a plastic case for external touch add-ons/overlays. The controller determines what type of interface/connection you will need on the PC. Integrated touch monitors will have an extra cable connection on the back for the touchscreen. Controllers are available that can connect to a Serial/COM port (PC) or to a USB port (PC or Macintosh). Specialized controllers are also available that work with DVD players and other devices.

How Touch Screen Work Software Driver
The driver is a software update for the PC system that allows the touchscreen and computer to work together. It tells the computer's operating system how to interpret the touch event information that is sent from the controller. Most touch screen drivers today are a mouse-emulation type driver. This makes touching the screen the same as clicking your mouse at the same location on the screen.

Resistive Touchscreen Technology
Resistive LCD touchscreen monitors rely on a touch overlay, which is composed of a flexible top layer and a rigid bottom layer separated by insulating dots, attached to a touchscreen controller. The inside surface of each of the two layers is coated with a transparent metal oxide coating (ITO) that facilitates a gradient across each layer when voltage is applied.

Resistive Touchscreen Technology
Pressing the flexible top sheet creates electrical contact between the resistive layers, producing a switch closing in the circuit. The control electronics alternate voltage between the layers and pass the resulting X and Y touch coordinates to the touchscreen controller. The touchscreen controller data is then passed on to the computer operating system for processing.

Touch screen Polyester Film Upper Resistive Circuit Layer
Conductive ITO (Transparent Metal Coating) Lower Resistive Circuit Layer Insulating Dots Glass/Acrylic Substrate Touching the overlay surface causes the (2) Upper Resistive Circuit Layer to contact the (4) Lower Resistive Circuit Layer, producing a circuit switch from the activated area. The touchscreen controller gets the alternating voltages between the (7) two circuit layers and converts them into the digital X and Y coordinates of the activated area.

Reference Jeff Tyson, How LCDs Works, http://www.stuffo.com. 1998-2005
Lachlan L. Mackinnon. Notes: Multimedia Technology (F291G2). Heriot_Watt University. Edinburgh. Scotland What is a touchscreen? touchscreens.html. FastPoint Technologies Inc How Does a Touchscreen Work?

CHAPTER 14 INTRODUCTION TO VIRTUAL REALITY SARASWATHY SHAMINI Adapted from Notes Prepared by: Noor Fardela Zainal Abidin © UNITEN 2004/2005

360 360 360 360 360 360 360 360 Objectives At the end of this chapter, students should be able to: identify the terms and concept related to virtual reality describe the two approaches in Virtual Reality describe the different types of Virtual Reality understand how virtual reality can be applied in everyday life

What is VR? Virtual reality (VR) refers to a set of techniques for creating synthetic, computer-generated environments in which human operators can become immersed. Virtual Reality is a way for humans to visualize, manipulate and interact with computers and extremely complex data

What is VR "Virtual Reality (VR) is a technology that makes use of 3D graphics, simulation, and special interfacing devices . VR is about using computers to create images of 3D scenes with which one can navigate and interact.

What is VR Virtual Reality is 3D computer Simulation
Providing sensations (sight, sound, touch, force feedback etc) Making you feel you are really in a “place”

Virtual Environment Virtual Environment or VE is
Real-time simulation of real or imagined environment Experienced at least visually VE Supports navigation through VE Supports 3D pointing Supports interaction with dynamic scene elements.

Virtual Environment Telepresence Immersion Virtual World
Experience of being present at virtual site Immersion Sense of being surrounded by sensory experience Virtual World Is large and unbounded VE with background like sky

2 Approach in VR Realist Approach Constructivist Approach

1) Realist Approach Uses VR as Example Recapitulation of Reality
Means of making realities of situation manifest Medium for exploring possible realities Example Computer aided design: living space design Distance learning: remote presentation Simulation: re-enactment of accident Training: flight simulators Modeling: Geographic information systems

2) Constructive Approach
Use VR as Artificial construct Means of social interaction and cultural expression Medium to be understood using theatre and film concepts Example Creative Expression – Cyber Art Fantasy Gaming – Sim City, Quake Intellectual Aid – Information Visualisation Social Encounters - Cybermalls

Types of VR Window on World Systems (WoW) Video Mapping
Immersive Systems Telepresence Mixed Reality

Types of VR Window on World Systems (WoW)
Some systems use a conventional computer monitor to display the visual world. This sometimes called Desktop VR or a Window on a World (WoW). Quote "One must look at a display screen," he said, "as a window through which one beholds a virtual world. The challenge to computer graphics is to make the picture in the window look real, sound real and the objects act real."

Types of VR Video Mapping
A variation of the WoW approach merges a video input of the user's silhouette with a 2D computer graphic. The user watches a monitor that shows his body's interaction with the world.

Types of VR Immersive Systems
The ultimate VR systems completely immerse the user's personal viewpoint inside the virtual world. These "immersive" VR systems are often equipped with a Head Mounted Display (HMD). This is a helmet or a face mask that holds the visual and auditory displays. The helmet may be free ranging, tethered, or it might be attached to some sort of a boom armature. A nice variation of the immersive systems use multiple large projection displays to create a 'Cave' or room in which the viewer(s) stand. The Holodeck used in the television series "Star Trek: The Next Generation" is afar term extrapolation of this technology.

Types of VR Telepresence
Telepresence is a variation on visualizing complete computer generated worlds. This a technology links remote sensors in the real world with the senses of a human operator. Fire fighters use remotely operated vehicles to handle some dangerous conditions. Surgeons are using very small instruments on cables to do surgery without cutting a major hole in their patients. Robots equipped with telepresence systems have already changed the way deep sea and volcanic exploration is done. NASA plans to use telerobotics for space exploration.

Types of VR Mixed Reality
Merging the Telepresence and Virtual Reality systems gives the Mixed Reality or Seamless Simulation systems. Here the computer generated inputs are merged with telepresence inputs and/or the users view of the real world. A surgeon's view of a brain surgery is overlaid with images from earlier CAT scans and real-time ultrasound. A fighter pilot sees computer generated maps and data displays inside his fancy helmet visor or on cockpit displays.

VR Advantages Better Communication. Enabling faster completion of projects Presentation are usable for difference purposes Able to view aspect that would either wise never show up or to late. Usually more affordable than building a scale model or mock up. Cost effective and safer. Ex: flight simulation

VR Dis-advantages VR world is visually unconvincing because there are sometimes low resolution, have limited field of view and exhibit noticeable head motion lags VR world lack realism and cartoonish VR can make you sick because of motion tracking and conflict in visual display VR is expensive to create Dependent on rare and specialized display devises Require special computing hardware.

BOOM Display Binocular Omni-Orientation Monitor
Puts high resolution stereo display on counterbalance arm. Is moves by hand grips or attached to user’s head Provides accurate head tracking Is only single user experience Tethers and restricts range of movements

BOOM Display

Desktop VR Provides VE display on desktop monitor
Usually is not head tracking Is cheaper and accessible Is not immersive (field of view limited) Is not encumbering Really enquires 3D pointer for interaction

Desktop VR Desktop VR can be delivered in a variety of modes
Stereo to screen shutter glasses Stereo to polarized screen overlay and polarized glasses Non stereo output to immersive wide screen display.

Desktop VR

Goggles and Gloves Impressively integrates
Stereoscopic viewing via LCD display Head and hand tracking Finger flexion input from data gloves Is only single user experience Limits corporal presence in VE to hand Suffers from high latency & limited accuracy of tracking Is encumbering: tethers user by wire or by IR comms range Has health hazard: bumping & cybersickness

Goggles and Gloves

VIRTUAL ROOM Cave Automatic Virtual Environment
Is 10-foot-square room composed of projection screens Use projectors to project stereo images on 3 walls & floor Gives perspective control to user with e-m tracker & wand CAVE was 1st developed in 1991 at Electronic Visualization Label Cave s unencumbering Sharable expensive

VIRTUAL ROOM

HMD Head Mounted Device
Is any device which literally mount on the head and displays an image viewable only by the wearer of the device. It is used for a wide variety of commercial, industrial, medical and personal applications.

INPUT DEVICES Mechanical Input Devices Electromagnetic Input Devices
Boom trackers, feedback mice, joysticks, steering wheel. Electromagnetic Input Devices Transmitter generates magnetic field in 3 orthogonal coils Receiver picks up field emission Sensors are small and may be attached o body, stylus, glove etc.

INPUT DEVICES Optical Input Devices Acoustic Input Devices
Light sources tracked by sensors Either sources or sensors are mounted on tracked objects Infra-red’s lack of visibility does not distract Acoustic Input Devices Microphones received ultra-sound pulses sent by emitters

MSC – Virtual Reality Center

Reference Funding A Revolution Government Support for Computing Research. Copyright 1999 National Academy Press VR4.1-VR.html Hamish Taylor, lecture Notes Multimedia technology 12.5G2, Heriot-Watt University Scotland.

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