Heinemann Information Processes and Technology: HSC Course

The answers below are, in many cases, only a brief guide to a full answer. Some of the answers in the learning activities have not been provided as they involve the student investigating, forming opinions, working in a group or completing practical tasks on the computer.

Chapter 7: Multimedia systems

Exercise 7.1 1 A multimedia system is an information system that combines different types of media. It uses at least three media types, such as text, images, animation, audio and video.

2 Seven types of media used in a multimedia product are text, hypertext, numbers, audio, images, animations and video.

3 Text refers to letters, numbers and other characters whose meaning and format is not specified. It has no meaning until a person reads and interprets it. Numbers refers to predefined characters, usually numerals, whose meaning and format are specified. Calculations are often performed on this data type.

4 A hyperlink is the highlighted item, usually an underlined word or graphic, which allows the electronic connection to another image or screen.

5 Audio has become an essential part of most multimedia products as it is used to explain concepts, reinforce selections and provide special effects.

6 Bit-mapped graphics produce good quality images where shading and detail are needed. However, when transformed (resized or stretched), bit-mapped graphics become ragged and suffer loss of resolution.

7 Video starts with a continuous event and breaks it up into discrete frames. Animation starts with independent pictures and puts them together to form the illusion of movement.

8 Interactivity allows the user to choose the sequence and content of information.

1 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course 9 The current image being displayed is stored in a section of memory called the frame buffer.

10 Sampling rate is the number of times a sample (slice) is taken from the sound wave. Sample size (or bit resolution) is the number of bits per sample.

11 Frame rate is the speed of a video or animation. It is measured in frames per second (fps).

12 Cell-based animation involves drawing and displaying individual frames or cells. Each frame is stored separately and loaded into a graphics page of primary memory. Path-based animation involves displaying the movement of objects onto a fixed background in a particular sequence or path. The pixels in the background do not change, only those for the moving object.

13 Tweening generates the intermediate frames between two frames drawn by the animator.

14 Morphing is a smooth change from one image to another. It may involve changes in shape, size or colour.

15 People involved in multimedia systems include:

 Content providers―people who provide the material for the multimedia product.

 System designer―plans and organises the hardware and software required for the presentation.

 Project manager―organises the scheduling of various components of the product.

 Technical staff―variety of artists and technicians who will edit the graphic and video material, text and all other material into appropriate formats for the final document.

LEARNING ACTIVITIES 1 a 38 Kb.

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2 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course d 1280 Kb.

e 3888 Kb.

2 a 5.04 Mb.

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3 a 263.67 Gb.

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5 A multimedia display for a kiosk could use media types of text, audio, images, animations and video.

 Text―heading, information about shops.

 Audio―music identifying a shop or product.

 Images―photo of shopping centre staff.

 Animation―transition to another screen.

 Video―shop or product.

6 Internet television has the potential to reach more users throughout the world (wider audience), users can immediately respond to Internet television using email, it is generally produced on a smaller budget, and at present there are fewer restrictions on the content imposed by governments.

7 Photo realistic images require at least 24-bit colour. Compressed file format such as GIF or JPEG would be suitable.

3 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course Exercise 7.2 1 A good multimedia product that uses different media types can maintain the user’s interest. The interactive nature of multimedia allows the user to control the learning.

2 Computer games provide a high level of interactivity so that the responses of the user determine the game being played.

3 A distinct advantage is the interactive nature of multimedia. It allows the user to search using related keywords to find specific information.

4 Information kiosks commonly provide information about items, the location of items or a map to a particular product or service.

5 Virtual reality is the use of computer modelling and simulation to enable a person to interact with an artificial environment.

6 Virtual reality (VR) uses such interactive devices as goggles, head-up displays, gloves, or body suits.

7 Flight simulators are used to train pilots by modelling different scenarios and the reactions of the plane in those scenarios as realistically as possible.

8 Three significant advances in technology that have influenced multimedia are the World Wide Web, CD-ROM speed and DVD.

9 The Web is an interactive environment using hyperlinks. A hyperlink takes the user to another Web site, to another page within the Web site, or even to another location on the same Web page.

10 The factors that have made the Web a valuable multimedia tool are the increase in power of personal computers and in speed of access.

11 The improvements in the speed of CD-ROM drives have made multimedia products approach a more realistic level when video or sound is involved.

12 Digital versatile disk (DVD) is a disk format that can store large amounts of data. It is an optical disk storage medium that may replace audio CD, CD-ROM, videotape and video game cartridges.

13 DVD Video uses MPEG-2 format to compress data.

4 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course 14 A DVD-ROM is the same size as a CD-ROM but provides storage of 4.7 Gb to 17 Gb.

15 Universal disc format (UDF) is an important file structure as it has overcome problems of incompatibility with multimedia applications.

16 The three basic design principles for a multimedia product are:

 Consistency―layout, format, style should be the same throughout the multimedia product unless different media types demand a change.

 Ease of navigation―people need to understand the structure of the multimedia product and easily proceed to the information.

 Simple―do not use too many design elements as it often confuses the user. The overuse of colour, sound, and animations can be distracting.

17 Text colour contributes to the style and theme of a multimedia product. Colour draws attention to the text. Some colours should not be used together as they produce poor contrast and reduce readability, for example, blue text on a red background. Too many different colours can be distracting and reduce readability. A colour scheme is used to ensure the colours will result in a professional-looking multimedia product.

18 Titling is the placement of a caption to accompany an image or graphic element.

19 Audio and video should be used to create interest and provide information. An occasional burst of sound for special effects will focus the audience on the multimedia.

LEARNING ACTIVITIES 1 a Education and training. Participants―person being trained. Data/information―data presented on the topic using text, image, audio and video. Hypertext provides interactivity. Information technology―personal computer, CD-ROM, DVD, speakers, multimedia product. The purpose of multimedia use in education and training is to help people to learn.

b Leisure and entertainment. Participants―person using the computer game. Data/information―data presented in the computer game using text, image, audio, animation and video. Hypertext provides interactivity. Information technology―personal computer, CD-ROM, DVD, speakers, joystick, Copyright © Pearson Australia (a division of Pearson Australia Group Pty Ltd)

5 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course computer game. The purpose of multimedia use in leisure and entertainment is to provide enjoyment and amusement for people.

c Information. Participants―person using the multimedia product (encyclopaedia). Data/information―data presented in the multimedia product using text, image, audio, animation and video. Searching on keywords, navigation buttons, and hypertext provide interactivity. Information technology―personal computer, information kiosk, CD-ROM, DVD, speakers, multimedia product. The purpose of multimedia use in information is to make it easier for people to display and understand data.

d Virtual reality and simulation. Participants―person using multimedia product (virtual reality system, flight simulator). Data/information―data presented in the artificial environment using text, image, audio, animation and video. Information technology―computer system, interactive devices (goggles, head-up displays, gloves, or body suits), motion sensors, flight simulator, multimedia product. The purpose of multimedia use in virtual reality and simulation is to enable a person to interact with an artificial environment.

2 a Similarities―both types of encyclopaedia contain ordered information and present data using text and images.

Differences―a multimedia encyclopaedia uses audio, video, animation and hypertext to display information; allows a keyword search; is interactive, allowing the user to control the information presented; and is easier to update. A print encyclopaedia does not require the use of a personal computer.

b A multimedia encyclopaedia uses text, hypertext, image, audio, animation and video.

c Searching on keywords and hypertext provides interactivity.

d The navigation methods in a multimedia encyclopaedia could be improved by allowing the user to ask a question and the encyclopaedia interpreting the question and providing the answer.

3 Student investigation of Web sites.

4 Practical task to develop an interactive multimedia product about the local community.

6 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course 5 Practical task to develop an interactive multimedia product about important developments in computer technology.

Exercise 7.3 1 A cathode ray tube (CRT) displays images by firing a beam of electrons onto the inside of the screen consisting of tiny dots, or pixels, made of phosphor.

2 A cross fade is the process by which the colour of a pixel changes gradually from its original colour to a new colour.

3 A raster scan fires the electron beam in a series of zigzag lines that starts in the upper left-hand corner and moves left to right and top to bottom. A vector display system directs the electronic beam to draw only the lines required for the image.

4 Interlaced monitors speed up refreshing by first scanning the odd lines from top to bottom, and then the even lines.

5 A liquid crystal display (LCD) consists of a layer of liquid crystal material placed between two polarising sheets. Light is passed through the liquid crystal material, and current is applied at particular points.

6 A data projection panel is a device that can be used together with a standard overhead projector to project an image from the computer screen onto a wall or white screen. The projection panel uses LCD technology to display the image from the computer. Light passes through the image much like a normal overhead projection slide.

7 Sound in a speaker is generated electromagnetically. A coil of wire is attached to a cone or diaphragm. The coil is placed around a permanent magnet, so that an electronic signal passing through the coil magnetises it. As the coil is magnetised, it pulls and pushes against the permanent magnet, causing the cone to vibrate according to the strength of the electronic signal. The movement of the cone makes the air near the cone vibrate, and this creates sound waves.

8 Presentation software can create several types of documents, including:

 On-screen presentations―slides displayed on a monitor or projected onto a screen.

 Audience handouts―images of two or more slides on a page.

7 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course  Overhead transparencies―slides printed as an overhead transparency in black and white or colour, using either portrait or landscape orientation.

 Speaker’s notes―notes the speaker needs when discussing the slides.

9 Application software used in multimedia systems includes:

 Word processors―text. Some word processors allow documents to be created with images and sound.

 Spreadsheets―text and number. Spreadsheets are also used to produce different types of charts used in multimedia.

 Graphics software―creates and edits images.

 Audio software―creates and edits audio.

 Video software― creates and edits video.

10 Authoring software is used to combine text, graphics, animation, audio and video into a multimedia product. The software allows the user to bring together the separate media types.

11 Three different types of animation software are 2D animation software, 3D animation software, and warping and morphing software.

12 Web browsers will receive multimedia files that are embedded in a Web page.

LEARNING ACTIVITIES 1 Presentation software is used to make a professional presentation to an audience. It could be used to create on-screen presentations, audience handouts, overhead transparencies, and speaker’s notes. Processes used to create the presentation involve researching the requirements of the HSC, drafting a storyboard for the presentation, entering the data into presentation software, formatting slides, adjusting timing and creating audience handouts.

2 The following is an example of how Table 7.5 might be filled in:

Media Name of software Default file format Text Word processor DOC Audio Real Audio player RealAudio Bit-mapped graphic Paint program BMP Vector graphic Draw program CGM Animation QuickTime QuickTime

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Video Adobe Premiere MPEG 3 Practical task on audio software.

4 Practical task on multimedia content.

Exercise 7.4 1 Three common types of scanners are:

 Hand-held scanners used to enter text and images that are less than a page wide. Hand-held scanners are adequate for small pictures and photos but are difficult for an entire page.

 Flat bed scanners that look similar to a small photocopier with the document remaining flat and stationary during the scanning

 Overhead scanners that look like an overhead projector. Documents are placed face up on the scanning bed, and a small overhead tower moves across the page.

2 The main advantage of digital cameras is that making the photos is both inexpensive and fast because there is no film processing.

3 Video capture cards convert analog form in a super VHS-format video into digital form. They interpret each frame of the video as a bit-mapped image. Video capture cards also compress the video clip by using a compression algorithm that analyses the changes from one frame to the next. They encode the starting frame and a sequence of differences between the frames.

4 A composite video system sends all the video information using one signal.

5 The rate of capture may vary, but usually video frames are around 30 per second.

6 Four storyboard layouts are:

 Linear layout―a simple sequential path that is set up quickly.

 Hierarchical layout―a sequential path in a top-down design. The user starts at the beginning and moves down through the multimedia product.

 Non-linear layout―no structure. The user moves between different layouts in any direction.

9 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course  Combination layout―a blending of the above layouts.

7 Compression reduces the number of bits required to represent information. It allows the user to store more data and makes data transfer faster.

8 The major difference between GIF and JPEG formats is the colour support. GIF files are limited to 256 colours, whereas JPEG images can use the full spectrum of 16.7 million colours.

9 A coder-decoder (CODEC) is used to encode and decode (or compress and decompress) various types of data. It converts analog video signals into compressed video files (such as MPEG) or analog sound signals into digitised sound (such as RealAudio).

10 Hypermedia involves the linking of information in different types of media.

11 Lossy compression removes a number of data bytes from the file. The resulting file is smaller in size, but the quality is reduced. Lossless compression allows the original file to be recovered in full. It works by replacing repeated data with something that takes up less room.

12 An ASCII, or text, file is a standard format used to store text and numeric data. It is essentially raw text without any formatting. An RFT file is an ASCII file with special commands to indicate the formatting of characters and paragraphs.

13 JPEG stores bit-mapped graphics. JPEG files are compressed using lossy compression with a compression ratio up to 100:1. JPEG is a popular choice for the Web. It is best used for photos and continuous tone images. JPEG images can use the full spectrum of 16.7 million colours.

14 EPS stores vector graphics. This format is commonly used for files that will be output on high-resolution devices. EPS files are not viewed directly on the screen.

15 A MIDI file contains note information and not details of the sound wave. It requires less storage.

16 MP3 has made it possible to download quality audio from the Internet.

17 Two common file formats for video are:

 MPEG files achieve a high compression ratio by using lossy compression and only storing the changes from one frame to another. MPEG-1

10 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course standard provides a video resolution of 353 x 240 at 30 FPS. It is similar to the quality of conventional VCR videos. MPEG-2 standard offers resolutions up to 1280 x 720 and 60 FPS. It is sufficient for all major TV standards and is used on DVDs.

 QuickTime is a video and animation format developed by Apple Computer. It is built into the Macintosh operating system and used with most Macintosh applications. Apple has provided a QuickTime version for Windows.

LEARNING ACTIVITIES 1 Hierarchical layout allows you to start at the beginning and move down through the multimedia product. A non-linear layout may also be appropriate as you can move between different layouts in any direction.

2 MP3 would be a suitable audio format as it compresses the file and is commonly used on the Internet. MPEG is a suitable video format as it achieves a high compression ratio using lossy compression and is also commonly used on the Internet. Both formats require additional plug-ins.

3 Student investigation.

4 Practical task to convert images.

5 Linear layout allows only a simple sequential path. This will be a problem as information about a school either is hierarchical or has no structure. I would suggest a combination layout.

6 a Hardware for collecting―digital camera and video, scanner, microphone.

b Application software―word processor, graphics software, audio software, video software.

c File formats―text (DOC or ASCII), image (BMP or JPEG), audio (MP3), video (MPEG).

d Hardware for display―LCD screen on laptop, data projection panel or data projector, speakers.

e Software to display presentation―authoring software, such as HyperCard.

7 Practical task on a Web site for latest CD releases.

11 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course Exercise 7.5 1 Copyright law protects the work of authors and artists. You are not allowed to use or copy the work of another person without their permission.

2 To cite an Internet source, include the following information:

 Author’s surname and initial or organisation’s name.

 Title of the completed work or Web page.

 URL of the page.

 Data of document or Web page publication.

 Download date.

3 With music files, it is legal to rip music from your own CDs. It is also legal to download music from Web sites where the artists own the rights. However, playing or distributing any other music files is breaking the copyright law. Even if you listen to streamed music from a Web site, the original artist must give permission.

4 The issue of copyright is a moral issue. Is it right to copy the original work of an author or artist without their permission? Authors and artists often spends hundreds of hours developing a product and deserve some returns for their efforts. The fact that it is relatively easy for anyone with a computer to make copies of the product is irrelevant.

5 Live video data raises the issue of privacy. Digital video cameras are being located in streets and streamed live on the Internet. People who are walking down the street are not aware of this nor have they given permission to be on the video.

6 Communication capabilities are now essential for a computer system, and computer technology is essential for communication. When people buy a personal computer, they purchase a modem and connect it to a phone line to access the Internet. Similarly, telephones have become data entry terminals into computer systems. Organisations are asking individuals to make choices using the keypad on the telephone.

12 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course 7 Advances and cost reductions in processing speeds, storage capacities, miniaturisation and the speed of electrical components have made the use of digital data more affordable.

8 Digital television will offer more channel choices, a higher resolution screen and greater control over the program you are watching.

9 Data integrity is an ethical issue as there is no guarantee of the reliability of the data in multimedia systems. It raises a number of issues. Who is responsible for the accuracy of information? Is the creator the only person responsible for the accuracy of the data? Do organisations that provide access to information in a multimedia system have a responsibility to verify its accuracy?

LEARNING ACTIVITIES 1 Positive aspects of multimedia systems are in the major areas of use: education and training, leisure and entertainment, information and virtual reality/simulations. Students need to describe some of the changes in these areas.

Negative aspects of multimedia systems include issues of copyright, privacy, data integrity and equity.

2 Student opinion. Active billboards will distract the driver and may cause accidents and traffic congestion. Active billboards will probably happen but need to be strategically located.

3 Student opinion. The ethical issues are copyright and plagiarism. Teachers should assess the development of students’ work, as well as the final product. The student should be disqualified and receive zero marks. A letter or report should be sent to the parents about the disqualification.

4 Student opinion. Multimedia systems will get more powerful and link to the Internet. Applications of multimedia will expand.

5 Practical task on downloading MP3 files.

6 a Privacy issues―permission to display images of staff and students. Personal data such as names, address, phone numbers and email addresses should not be included in the Web site.

b Original work―check whether the school owns the copyright or has permission to use the data on the Web site.

13 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course Chapter review 7 PART A 1 D 2 C 3 A 4 A 5 D 6 C 7 A 8 D 9 A 10 B PART B 1 (h) copyright 2 (m) image 3 (o) bit depth 4 (c) audio 5 (l) JPEG 6 (e) HTML 7 (g) GIF 8 (j) vector 9 (b) hotword 10 (n) MP3 11 (k) CRT 12 (a) frame grabber 13 (p) sampling rate 14 (i) bit-mapped 15 (d) video 16 (f) sample size PART C 1 The types of media used in a multimedia product include:

 Text refers to letters, numbers and other characters whose meaning and format is not specified.

14 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course  Numbers refers to predefined characters, usually numerals, whose meaning and format are specified.

 Hypertext allows the user to navigate through the multimedia product. It is a system that allows documents to be cross-linked in such a way that the user can explore documents by clicking on a link.

 Audio is sound that has been digitised.

 Images are pictures, such as drawings, paintings or photographs.

 Animation is the movement of a graphic.

 Video combines pictures and sounds displayed over time.

2 Similarities―both presentation types contain ordered information and present data using text and images.

Advantages of a multimedia presentation―can use all media types to display information, allows a keyword search, is interactive allowing the user to control the information presented, is easier to update.

Disadvantages of a multimedia presentation―requires the use of a computer system, requires people who are experts in a particular field to create the product, places large storage and processing demands on the computer.

3 a The project manager organises the scheduling of various components of the product, is responsible for the overall supervision of the components and ensures that all components are delivered on time.

b Other team members:

 Content providers are people who provide the material for the multimedia product. This may include text, graphics sketches or final drawings, video footage and audio tracks.

 The system designer plans and organises the hardware and software required for the presentation.

 The technical staff comprises a variety of artists and technicians who will edit the graphic and video material, text and all other material into appropriate formats for the final document. The technical staff also

15 Chapter 7 Answers Heinemann Information Processes and Technology: HSC Course includes layout and design personnel who work to develop an overall theme and look of the product.

c Hardware for multimedia system―fast processor, large primary storage, high- resolution screen, large hard disk, DVD, speakers, joystick.

Software for multimedia system―authoring software, application software.

4 a Essential features―consistent layout, format and style; easy navigation; simple with not too many design elements; interesting content; fast loading.

b Open ended task to construct a storyboard.

c Student opinion.

d Navigation path is given in the storyboard layout―hierarchical or non-linear.

e Student photos involve privacy―permission to display images of staff and students. Personal data, such as names, address, phone numbers and email addresses, should not be included in the website.

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