Chapter 9

Multimedia Essentials

 

 

This chapter is written to give students a broad grounding on issues surrounding multimedia. Multimedia is the integration of multiple media such as graphics, text, sound, video, and animation elements, which together make an influence on the given information so that it can be presented in a pleasing and interactive manner. The chapter starts by discussing various components of multimedia—text, graphics, digital audio, video, and animation. The discussion is continued by providing an outlook on multimedia system and data compression. A detailed overview on multimedia applications and virtual reality completes the chapter.

9.1 INTRODUCTION

The changing face of technology has taken humankind into an entirely new era, the “information age”, and the ability of state-of-the-art electronic tools to gather, refine and shift data have opened new vistas for data presentation. Presentation applications involving imaginative use of “multimedia” allow for new and more powerful and personalized modes of representing data. Multimedia is the use of a combination of text, graphic and audio, and aids in the presentation of information. Devices such as television, computer and video recorder are multimedia devices as they present information in combinations of text, graphics, animation, audio or video.

With the development of multimedia and Internet technology, people's outlook on information representation has changed completely. Growth in the Internet technology has emerged as a cost-effective means of communicating ideas across the world. Internet technology has helped multimedia in spreading its magic in almost every aspect of data communication. We feel and see multimedia in every aspect of our daily routine, in cinema halls, discos, amusement parks and public kiosks. Nowadays, multimedia technology is extensively being used in schools, businesses, homes and public places to present information to people, employing both knowledge and entertainment together for interactive presentations. With the advancement in computer hardware and software, multimedia has the perfect launching pad to rule the field of information presentation and communication.

9.2 MULTIMEDIA: DEFINITION

The word multimedia is made up of two separate words, multi meaning many, and media meaning ways through which information may be transmitted. Therefore, multimedia can be described as an integration of multiple media elements together to influence the given information so that it can be presented in an attractive and interactive manner. In simple words, multimedia means being able to communicate in more than one way.

Traditionally, information was presented in a single medium only (unimedium presentation), be it newspaper, or radio, or television. With the development (and literally the most preferred means of information communication nowadays) of computers, presenting data has taken an entirely new meaning. Today, almost every computer can present data using a variety of mediums such as text, graphics, animation, audio and/or video. Hence, multimedia can be defined more appropriately as a technique that supports the physical and logical coexistence and interactive use of heterogeneous media classes, such as print, audio and video in specific application environments.

Newspapers were perhaps the first mass communication medium to employ multimedia— they used mostly text, graphics and images. Later radio was developed, which is now a major medium for audio broadcasting. Then the television was invented that brought the video and changed the world of mass communication. After the invention of computers, multimedia is talked mainly in reference with computers. We can even say that multimedia is a computerized method of presenting information by combining audio and video components. For example, a multimedia database of musical instruments may allow a user not only to search and retrieve text about a particular instrument but also to see its pictures and play a piece of music. The advent of high-resolution screens and sound and video playback facilities for computers has resulted in the increased use of multimedia applications. A typical multimedia application is characterized by the following features.

• It possesses and makes use of different media
• It uses digital technology
• It demands interaction from the user
• It integrates sound, images, text and data into seamless applications.

9.3 BUILDING BLOCKS OF MULTIMEDIA

As discussed, multimedia is mainly concerned with the computer-controlled integration of text, graphics, drawings, still or moving images (video), animation and audio where every type of information can be represented, stored, transmitted and processed digitally (Figure 9.1). By definition, the media class print includes static media types such as text, graphics, facsimile and natural images; the media class audio includes dynamic media types such as natural and synthetic sound, speech and music; and finally, the media class video includes dynamic media types such as natural and synthetic image sequences.

 

 

In the case of computers, the most commonly used multimedia mediums are the following:

• Text: The on-screen display of words, that is, text, is the base of most applications. Different styles, fonts and colours can be used to emphasize specific points.
• Graphics: Seeing a picture of an object has more impact than merely reading about it. Graphics include conventional artwork, computer-generated artwork and photographs or captured video frames.
• Audio: This includes speech, audio effects, ambient sound (for example, the background sound of the sea) and music.
• Video: This includes displaying real-life events that are recorded using digital video recorder. For example, a movie.
• Animation: Animation is the timed sequence of a series of graphics or frames together to give the appearance of continuous movement.

9.3.1 Text

Humankind developed text and symbols so that they could communicate. Writing helped human to remember things for a much longer period than what is possible with the help of memory (brain). Soon the written messages became popular. Reading and writing skills are prevalent in most modern cultures. As has been the case throughout history, text still delivers information that is concentrated and meaningful. Words and symbols in any form, spoken or written, are the most common means of communication.

The advancement in representing textual messages has completed a full circle. These days not only is the text capable of displaying information, but it has also gained interactivity; things like an electronic annotation, which assist in navigating through all the information presented on the Web by means of hypertext. A hypertext can be defined as an object in the text that allows the user to jump from one web page to another at a click of the mouse button (Figure 9.2). It acts like electronic footnotes and assists you in navigating through all the information.

 

 

The amount of text to be included in an application, the type of font selection, the size, style and colour of the font make the application more meaningful. Text files are usually stored character by character. Files may contain raw text or formatted text. For example, Hypertext Markup Language (HTML), a program language source (C, Pascal) or Rich Text Format (RTF)—a file format for text files that includes formatting like different font styles and typefaces and so on. The basic storage of text is one byte per character (text or format character). For other forms of data such as spreadsheet files, some may store format as text (with formatting), others may use binary encoding. Even though the storage requirement of this media is not high, when data is stored on disk, small files may take larger disk storage requirements due to block and sector sizes of disk partitions.

Text can be written using various text editing and processing tools. The most commonly used tool is a Word Processing Software such as Microsoft Word and Word Perfect where a text file can be developed and later imported into the multimedia authoring tools to integrate with other media elements (Figure 9.3). Typically, a word processor includes grammar and spelling checkers, template for letter writing, mail merging and many more features to enhance ordinary text into rich text.

 

9.3.2 Graphics

Graphic is a generic term used to describe the pictorial representation of data. When we talk about graphics, we generally tend to refer those pictorial representations that are created by primitive objects, such as lines, polygons, circles, curves and arcs. For example, a picture of a cube can be drawn using lines and a pie chart can be drawn using lines and arcs. Images are still pictures that are represented as a bitmap (a grid of pixels [Figure 9.4]). Graphics are usually editable or revisable (unlike images). Generally, graphic input devices include keyboard, mouse, trackball or light pens. Graphic files usually store the primitive assembly and do not take up a very high overhead. Images may be generated by programs similar to graphics or animation programs. They can also be scanned using a digital scanner or from a digital camera. Images may be stored at one bit per pixel (black and white), eight bits per pixel (greyscale, colour map) or 24 bits per pixel (true colour). Typically, a 512 × 512 greyscale image takes up one-fourth of an MB, a 512 × 512 24-bit image takes three-fourth of an MB with no compression. This overhead soon increases with image size, so compression is commonly applied.

 

 

It is said that a picture is worth a thousand words; as a result, every multimedia presentation is predominantly based on graphics. By nature, human beings comprehend concepts more easily through graphics than textual information. Adding a graphic element into a text-based document can change the user's perception towards the document. Integration of the graphics element into the application makes it more elegant and understandable. Growing technology has produced a wealth of graphics and visual imagery for a multimedia project. For the development of a multimedia project, various images are captured from different sources like scanners, digital cameras and through the Internet. Once the images are transformed into a digitized form, they can be edited and modified with the help of image editing software like Adobe Photoshop, Corel Draw and Freehand (Figure 9.5).

 

 

In today's challenging world, representing thoughts effectively has become the basic need of the hour. No matter how good the multimedia presentation is, if the ideas of the presentation are not expressed in an effective manner then the presentation is a failure. One way of expressing imaginative ideas is by using graphics. Graphics can be presented in the following modes (Figure 9.6).

 

 

• Background: The background sets the tone and the theme of the presentation. It should be based on the type of information that is to be conveyed. For example, if the information is more text oriented, then simple background images should be used. In case the information is to be conveyed to little kids then the background should be more animated and colourful.
• Two-dimensional (2D) Graphics: Usually, when you look at a computer screen, you are looking at a two-dimensional image. The image spans from left to right and top to bottom but usually not in and out of the computer screen. A 2D image definition contains only information about how a scene appears from a particular point.
• Three-dimensional (3D) Graphics: The difference between 2D graphics and 3D graphics lies not in the way the images appear rather in the way they are defined. A 3D image contains information about the scene in three dimensions (x, y and z coordinates). However, this 3D data cannot be viewed directly. In order to view it, first the 3D data must be converted into a 2D image by the computer using a process known as rendering. The rendering process takes as input the 3D scene and the location and attributes of a camera and produces as output the 2D image that the camera sees from that particular point in space. The process is done by mathematically “projecting” a 3D scene onto a 2D surface. In photography, this is done by the camera lens, but in computer graphics, this is done by solving mathematical equations. In both cases, the result is a 2D image that has been generated from a 3D scene.
• Charts and Graphs: In business and training-related multimedia projects, charts and graphs are the most appropriate forms of graphics used for presenting facts and figures related information (especially numerical).
• Flowcharts: The use of flowcharts expresses the systematic order of an event. They are developed mainly to break the complex problem-solving steps into smaller, less complicated steps so that developing logic becomes easier.

9.3.3 Audio

Audio means the sensation resulting from stimulation of the auditory mechanism by airwaves or vibrations. It is the vibration of air molecules in the atmosphere that can be sensed by the ear. It involves transmission of mechanical vibration by an elastic medium that is capable of being detected by the human ear. Today, a computer can play back most complex parts of a melody with great precision. Computers and digital technology have changed the face of the music industry. Today, digital music is used to produce special effects in televisions, films, in recording studios and in games. Music and sound effects not only add interactivity with the user but also play with the user's perception and emotions. For example, speech can be used to offer commentary or help without obscuring information on the screen. Audio can also be used to provide a sense of place or mood as done to perfection in the game. Mood-setting audio should employ quiet background sounds so that it does not compete with the main information for the user's attention.

Music is probably the most obvious form of sound. It can be used to set a mood, convey an idea and even tell a story. Music influences how we think and feel and how we perceive other forms of information. Speech is also a perfect way for teaching users the pronunciation of words as done by the speech learning software. Non-speech sound effects can be used in the user interface to inform users about background events. For example, the sound of the progress of a file download could be signalled by the sound of water pouring into a glass that gradually fills up. These kinds of background sounds have to be non-intrusive. Sounds can be embedded into a web page and can be played. Common types of sound formats are MIDI and WAV. MIDI sound files are stored on a computer and contain musical notes, and sound information can be sent via a MIDI interface card to a musical instrument. MIDI files contain one or more MIDI streams with time information for each event. WAV sound files are the Microsoft standard file format for storing waveform audio data. These files are also known as universal files. A user can use these files through QuickTime and Windows Media Player. Once the audio files are recorded, they can be manipulated to produce the desired output using various sound-editing software like the Sound Forge (Figure 9.7).

 

 

9.3.4 Video

The term video refers to the moving picture accompanied by sound such as a movie on television. It is a medium that is as direct as print and catches more attention. It adds richness to content and enhances the user's experience. It dramatizes and gives impact to the multimedia application. Integrating a video element in a multimedia application provides a great deal of information in a short time. If used in a planned and well-executed manner, it can make dramatic differences in the multimedia presentation. Digital video is useful in multimedia applications for showing real life objects, such as people talking or real life illustrations of concepts. Video places the highest performance demand on the computer memory and on the bandwidth if placed on the Internet. Under these constraints, video has to serve as a supplement to text and images more often. Currently, video is good for the following:

• Promoting television shows, films or other non-computer media that are used as trailers in advertising.
• Showing things that move, such as a clip from a ballet and product demo of physical products.

Note: Bandwidth is defined as the amount of data that can be transmitted from one computer to another in a given time frame.

There are three main types of video files that are used: QuickTime, AVI, and MPEG (Figure 9.8). QuickTime and MPEG are the most commonly used file formats. AVI is a Windows-oriented video format that is not used because of problems like synchronizing both audio and video. Since QuickTime is readily available for Windows as well as Macintosh, the need for AVI is rapidly diminishing, at least on the Internet. MPEG's is the extremely high output quality. It delivers higher image resolution, picture quality, interlaced video format, multi-resolution scalability, and multi-channel audio features. It was developed as an international standard for use in CD-ROM, video games and other media that require high quality digital video. For the trade-off of using slightly larger files, one gets much higher-quality video, with up to 30 frames per second (the same as standard American television).

 

 

In terms of computers and Internet, the major problems with most videos are that their production quality is too low and they have a very large file size. To make video usable, video files need to be compressed in different file formats. One can even create one's own video files using video editing software such as Adobe Premier and Microsoft Moviemaker. Although it is time-consuming, the process of digitizing, editing and uploading video files is not an extremely complicated process. The only thing that should be of concern is the bandwidth that is being used. At 28.8 Kbps, a 1 MB file representing a few seconds of video will take about 10 minutes to download.

9.3.5 Animation

Animation is the process of sequencing still images in rapid succession to give the effect of live motion. The sequence of images is shown one after the other very quickly so that the human eye and brain blend the images to produce the effect of motion. It is a powerful tool capable of communicating complex ideas. It is often much easier to show somebody how things work than to try to explain it. Animation is viable because of a natural phenomenon known as persistence of vision. An object seen by the human eye remains mapped on the eye's retina for a short time interval after viewing. This makes it possible for a series of images that are changed very slightly and very rapidly, one after the other, to seemingly merge into a visual illusion of movement. In other words, if we just slightly change the location or shape of an object rapidly enough, the eye will perceive the changes as motion (Figure 9.9). An animated sequence has to show a certain number of frames every second. For professional animation, one needs to have at least 30 frames per second.

 

 

Animation can be useful because of the following:

• Continuity in Transitions: When something has two or more states, then changes between states will be much easier for users to understand if the transitions are animated instead of being instantaneous.
• Dimensionality in Transitions: Opposite animated transitions can be used to indicate movement back and forth along some navigational dimension. For example, following a hypertext link to a footnote might be shown by a “down” animation.
• Illustrating Change Over Time: Since an animation is a time-varying display, it provides a one-to-one mapping to phenomena that changes over time. For example, population growth can be illustrated by showing a map with an animation of population changing over time.
• Multiplexing the Display: Animation can be used to show multiple information objects in the same space. For example, whenever the user moves the cursor over the various hyperlinks, an explanation for each is popped-up in the form of tool tip.
• Visualizing 3D Structures: Since the computer screen is two-dimensional, users can never get a full understanding of a 3D structure by a single illustration, no matter how well designed it is. Animation can be used to emphasize the three-dimensional nature of objects and makes it easier for users to visualize their spatial structure.
• Attracting Attention: Animation has the ability to control a user's visual awareness and this advantage can be moulded in the interface. If the goal is to draw the user's attention to a single element out of several or to alert the user to updated information then an animated headline will do the trick.

Animations can be done in two ways: 2D animation and 3D animation. In 2D animation, flat images are drawn one frame after another. In 3D animation, a mathematical model of a 3D object is created to portray its width and height as well as its depth. 2D animations are more popular; most cartoons that you watch on television are based on 2D animation technique. 3D animation is mostly used in computer-aided design (CAD). The two most commonly used animation effects are kinematics and morphing. Kinematics is the study of movement and motion of structures that have joints, such as a walking person. This is a tricky and carefully executed task, as one requires calculating position, rotation, velocity and acceleration of all the joints. Morphing involves transformation of one image into another (Figure 9.10). Morphing and other modelling applications are performed on still as well as in moving images.

 

9.4 MULTIMEDIA SYSTEM

A multimedia system is a system capable of processing multimedia data and applications. It is characterized by the processing, storage, generation, manipulation and rendition of multimedia information. Computer hardware and software play a vital role in supporting multimedia-based applications. These applications consume a large amount of computer resources like storage space and I/O devices. Permanent storage is required to keep digitized information for future retrieval and use. Many multimedia products require storage on a CD-ROM. Multimedia also requires a large amount of a computer's main memory and a large amount of bandwidth when distributed on a network. Optical disk emerged recently as the most cost-effective means for distribution of a multimedia project. A good quality multimedia project needs a high capacity of RAM that would enable smooth functioning of the project. It should support adequate storage of data that contains text, graphics, audio, video and animations. As vast amount of data is required for the processing of multimedia elements, a faster processor speed is also essential along with the supporting RAM.

9.4.1 Desirable Features of Multimedia System

The minimum recommended hardware configuration needed by a multimedia personal computer to support a good multimedia application is as follows:

• High Processing Power: A multimedia system requires high processing power to deal with large data processing and real time delivery of media. A multimedia system should have a processor having a minimum of 500 MHz (or higher) of processing speed.
• Storage and Memory: Typically, all multimedia presentations are memory hungry, hence it requires large storage units (2–20 GB) and large memory (32–128 MB or more). For efficient management, a large cache memory, of Level 2 and 3 hierarchy, is also required.
• Operating System: Every multimedia system requires a special operating system that allows access to the file system and process data efficiently and quickly. It is also needed to support direct transfers to disk, real-time scheduling, fast interrupt processing, I/O streaming and so on.
• Software Tools: User friendly software tools are needed to handle media and design, develop applications, and to deliver the media. In addition, data representations/ file formats should be easy to handle and should also allow for compression/ decompression in real time.
• Sound and Display Cards: Since audio and video are basic components of any multimedia presentation, a good sound and colour display card (at least 8-bit) is necessary for any multimedia system.
• Efficient Input/Output Devices: Efficient input/output devices are needed to allow real-time recording as well as playback of data. Typically, a multimedia should be equipped with a high-resolution colour monitor, a CD-ROM drive (24× or higher), keyboard, three-button scroll mouse, a colour printer (300 dpi or more), scanner (300–500 dpi or more), video camera, audio and video recorders, a set of CD-quality speakers, and an audio microphone (see Figure 9.11).

   

  

   

  Figure 9.11 Typical Components of Multimedia Computer

   

• Network Support: In a business conference, where a multimedia presentation is on, we may require associated peripherals connected to a main computer via communication devices (modems, hubs and so on) to carry out the supportive role in running an application.

9.4.2 Data Compression

In terms of computers, the only limitation of using a multimedia presentation is that it consumes a lot of storage space. In order to reduce the storage space, the multimedia components must be “compressed”. Compressing a file refers to the process of cutting down the size of the file by using special compression algorithms. There are two types of compression techniques: lossy and lossless. In the lossy compression technique, some data are deliberately discarded in order to achieve massive reductions in the size of the compressed file. In this compression format, we cannot recover all of its original data from the compressed version. JPEG image files and MPEG video files are examples of lossy compressed files. On the other hand, in the lossless compression technique, the size of the file is reduced without permanently discarding any information of the original data. If an image that has undergone lossless compression is decompressed, the original data can be reconstructed exactly, bit-for-bit, that is, it will be identical to the digital image before compression. PNG image file formats use lossless compression. Similarly, text can be “losslessly” compressed using the ZIP tool.

Let us take some examples to illustrate both the compression techniques. Suppose you have two cups, one of 200 ml capacity (filled with water) and the other of 100 ml capacity (empty). Now pour water into the 100 ml cup and throw away the rest. This is lossy compression because you have kept only the necessary data and thrown away unimportant data. Now if you want to fill the 200 ml cup again with water from the 100 ml cup (recreating the original image), then you will find that the cup will not be filled because you have thrown away 100 ml of unwanted water (original image quality will not be retrieved). Lossless compression, on the other hand, does not use such technique. An analogy of this technique may be said to be the folding of paper. When the paper is folded, its size is reduced. However, you can get the original size of the paper by unfolding the paper, hence nothing is lost. Similarly, when an image is compressed losslessly, the quality of the image is retained even though the size is reduced.

Some Data Compression Techniques:    There are many known lossy and lossless compression techniques. Some of them are as follows:

• Predictive Encoding (Lossy): In digital audio or video, successive samples or frames are usually similar to each other. Considering this fact in this technique, the initial frame and the difference values in the successive frames for all the frames are stored in the compressed form. As the size of the difference values between two frames is much smaller than the size of the frame itself, this encoding technique saves much space. While decompressing, the previous frame and the difference value are used to reproduce the next frame.
• Run-length Coding (Lossless): In this technique, each repeated symbol in the given text is replaced with the symbol itself and the number of times it is repeated. For example, the text “cccccccbbbbuffffff” is compressed as “c7b4u1f6”. This technique is effective only when symbols in the text are being repeated many times.
• Variable-length Coding (Lossless): Generally, the frequency of occurrence of characters varies in the text. For example, the letter e of the English alphabet is used much frequently than z in a regular text. Exploiting this fact, we may use variable number of bits per character than a fixed number of bits per character that most coding schemes (like ASCII, BCD, etc.) use. Fewer bits are used to represent the more frequently used character; the most frequently used character can be represented by one bit only. This helps in reducing the length of the compressed data.

To understand this technique, consider a language comprising three letters: a, e and z with the probability of occurrence of 0.42, 0.54 and 0.04, respectively. Since e has the highest of occurrence, we use one bit to represent it. The bits that can be used for a, e and z are 10, 0 and 110, respectively. It means each occurrence of a is replaced with 10, each occurrence of e with 0, and so on. For example, the text “aeezea” is compressed to 1000110010 requiring 10 bits only. Note that with a fixed number of bits per character, we require 2 bits for each of the three characters (as 3 < 2²). Hence, a total of 12 bits would be required to represent “aeezea”. The variable-length coding technique is effective when the frequency of occurrence of characters is known and uneven.

9.5 MULTIMEDIA APPLICATIONS

The growing technology of computer's hardware and software, to hold several types of media, had made multimedia suitable for a wide range of applications and users. Here are some of the possible areas where the use of multimedia applications has replaced the conventional system with new technology.

9.5.1 Multimedia and Education

The goal of an instructor is to facilitate learning to help students gain a body of knowledge, acquire specific skills, and function successfully in society. One of the greatest challenges for instructors is the diversity of students, especially in the different ways they learn. Some students learn better through association, others by experimentation, some learn faster through visually oriented methods. Multimedia has the ability to accommodate different learning styles and can present material in a nonlinear manner. It is motivating, highly interactive and can provide feedback and evaluate skills. In the coming years, further advancement Figure 9.12 Using Multimedia in Education and acceptance of multimedia will change the face of teaching methodology. In some instances, teachers may find this as a new helping tool through which they can enhance their own teaching approach. They have found these tools appealing because of their ease of use and effective way of expressing information. Students prefer this new technology to the traditional text-based approach because of the multi-sensory experience they undergo, making them feel like having a game-like interface (Figure 9.12).

 

 

Students are found to be more motivated when using multimedia. Even teachers have stated that multimedia enables students to learn in an efficient and effective manner. With multimedia coming into picture, the teacher has become a facilitator, problem solver and guide as opposed to playing a central role. Interactive multimedia is a powerful tool for education that can be used in many different ways, such as support to class presentations, tutorial for off-class consultancies or complementary activities, virtual laboratories, simulators, centre of activities to be used in a laboratory or at home, distance or local guided study, case studies and virtual conferences.

9.5.2 Multimedia and Entertainment

Drawing the line between education and entertainment in multimedia is almost impossible. Hence, a new term has been coined, “edutainment”, which means using multimedia to make learning entertaining. However, multimedia also has a purely entertainment side. Anything that is possible in sound and images is possible on a multimedia CD. Multimedia means interaction, and to many interactive entertainment means games. In fact, game developers were the pioneers in the use of multimedia and they still provide the most innovative and interactive applications of multimedia. A game is one of those multimedia domains where all the elements of multimedia play an equally important role in making it realistic and interactive. In order to attract, engage, captivate and challenge the user, multimedia provides fast action, vivid colours, 3D animations and elaborate sound effects that are essential to entertainment (Figure 9.13). Today, many games have moved from the physical (hand/eye coordination) to the mental (solving the mystery or outwitting the opponent). On the other hand, hobbies and sports are examples of multimedia titles that provide the user with a vicarious experience such as being able to play the best golf courses in the world or simulate flying over 3D cityscapes.

 

 

Nowadays, multimedia is extensively being used in the field of television broadcasting and movies. For example, while watching a live match on television, we are habitual of seeing replays, slow motion, charts analysis and other statistical information. These kinds of integrations on the sports make a novice understand and envisage the sports in a better way. In movies, you might have seen the “Titanic sinking” or “dinosaurs roaming around”. These are just some of the amazing effects that multimedia has offered.

9.5.3 Multimedia and Training

In a corporate world, many multinational organizations invest huge sums of money in providing training to their staff members and employees. Consider a case where a traditional method of training is being implemented. A reputed organization sends a group of trainers with necessary training tools and equipments to different centres across the world. This training team charges expenses related to travel, stay at the hotel, food, salaries and so on. Now consider the alternate case where a multimedia-based training is implemented. All the necessary data and teaching methodology are packed in a small storage media, that is, compact disk. This method of training can be easily provided in different parts of the world for a long time. Multimedia technology serves as a reference tool for the corporate executives. An employee can perform, self test and practice to improve his efficiency on the job.

Every company has a need to train its employees on a wide range of subjects from personnel policy to equipment maintenance. A number of companies are now training employees using multimedia-enhanced training materials. This can be done using off-the-shelf multimedia titles, but many companies are producing their own in-house multimedia training products. For instance, the Boeing company has an entire training division dedicated to developing multimedia titles that instruct mechanics and pilots on new aircraft systems. Using multimedia tools, the trainee can perform a simulated job function in order to develop an advanced level without having touched the actual unit. The integration of audio and video permits this training technology to be a highly effective medium in areas such as flight and driving simulators (Figure 9.14). Similarly, NASA uses multimedia extensively for flight control training for astronauts.

 

9.5.4 Multimedia and Business

Some of the biggest users of multimedia are business organizations. As businesses have to communicate with the outside world, multimedia offers a wide variety of options for business presentations, marketing and sales (Figure 9.15). Multimedia can be used at trade shows or to produce electronic catalogues. The marketing of new products can be greatly enhanced by using multimedia; these products can be marketed in a manner that provides more detailed and stimulating information than print media. Auto manufacturers like Nissan provide interactive test drives of new vehicles on the Web or on CD. Macromedia now present their annual report, vision statement and product overview in print, on the Internet and in the CD-ROM form.

 

 

Use of the multimedia application in the business world has created a boom among the business industry around the world. One can run his/her business in a much organized and professional manner. Using multimedia application as a tool for conducting presentations, training sessions, marketing, advertising and communications via videophone in running a business has made awesome changes in the style of carrying out business. As compared to a conventional presentation, a multimedia presentation can make the audience come alive with the presence of ambient sound and visual effects. Its widespread use in training programs has helped people in carrying out their tasks in a much better way. For example, an automobile mechanic can learn to repair the engine of a car; security personnel can learn to tackle a bank robbery through simulation. Keeping records for the entire staff working in a big organization is a very cumbersome and challenging work. Integrating multimedia with the database management system, one can formulate the job in a much easier manner. Capturing images from the camera, storing voices along with the text data can make a secure database for the organization.

Multimedia technology marked its beginning with application in the advertising industry. Its power to boost communication at an affordable cost opened the way for the marketing and advertising personnel. Almost all advertisement and marketing agencies are well equipped with authoring tools and workstations. Presentations that incorporate flying banners, video transitions, animations and sound effects are some of the elements used in composing a multimedia-based advertisement to appeal to the consumer in a way never used before and promote the sale of the products. In addition, multimedia has incalculably increased the creativity of the marketing institutions. Today's computer has replaced high-priced sound and video editing facilities with reasonably priced equipment. The same computer is being used for a number of elements: sound, video, animation and so on.

9.5.5 Multimedia Interactive Kiosks

A multimedia kiosk is a kind of an automated information centre where one can get necessary information related to a particular context (Figure 9.16). Some of the common services provided by the kiosk are searching for necessary information, performing financial transactions, taking online shopping orders and many more. These kiosks are located near public places, such as hotels, railway stations, museums, historical monuments, bus stops and grocery stores, round the clock for the convenience of people, thereby eliminating the need for conventional-based information booths and staff members. In such kiosks, printers are often attached so that a user can walk out with a printed copy of the information. For example, a kiosk at a bus stop can be useful in providing a list of all the bus numbers plying on the respective routes, the arrival and departure time of the buses, fare for the Figure 9.16 Multimedia Kiosk different destinations and so on.

 

 

9.6 VIRTUAL REALITY

Virtual reality can be described as an artificial environment that is created by using special computer hardware and software, which is presented to the user in such a manner that it appears and feels like a real three-dimensional world. The original term for virtual reality was “immersive virtual reality”, which means the user becomes fully immersed in an artificial, three-dimensional world that is completely generated by a computer. To enter in virtual reality, a user wears special gloves, earphones and head-mounted display device (HMD), all of which receive input from the computer system (Figure 9.17). In this way, at least three of the five human senses are controlled by the computer. In addition to feeding sensory input to the user, the devices also monitor the user's actions. The HMD, for example, tracks how the eyes move and respond accordingly by sending new video input. Virtual reality is used in health care and mass entertainment among other things. However, even today, virtual reality systems require very expensive hardware and software, and they are confined mainly to research laboratories. Virtual reality requires tremendous computing power to be lifelike.

 

 

In virtual reality, cyber space is made up of thousands of geometric objects and points plotted in a three-dimensional space; the more the number of objects and points that describe the objects, the higher the resolution, therefore a more realistic view will be seen. Each motion or action requires the computer to perform recalculation on the position, angle and shape. Some of the devices that are used in virtual reality are as follows:

• Head Mounted Display (HMD): The HMD was the first device providing its wearer with an immersive experience. A typical HMD has two miniature display screens and an optical system that channels the images from the screens to the eyes, thereby presenting a 3D view of the virtual world. A motion tracker continuously measures the position and orientation of the user's head and allows the image-generating computer to adjust the scene presentation to the current view. As a result, the viewer can look around and walk through the surrounding virtual environment.
• Data Gloves: The glove is equipped with sensors that sense the movements of the hand and interfaces those movements with a computer. Data gloves are commonly used in virtual reality environments where the user sees an image of the data glove and can manipulate the movements of the virtual environment using the glove.
• Software: Software gives the wearer of this special headgear and gloves the interactive sensory experience that feels like an alternative to real-world experiences.

9.6.1 Characteristics of Virtual Reality

Virtual reality presents many characteristics, some of which are as follows:

• Head-referenced viewing provides a natural interface for navigation in three-dimensional space and allows for look-around, walk-around and fly-through capabilities in virtual environments.
• Stereoscopic viewing enhances the perception of depth and the sense of space.
• The virtual world is present in a full scale and relates properly to the human size.
• Realistic interactions with virtual objects via data glove and similar devices allow for manipulation, operation and control of virtual worlds.
• The convincing illusion of being fully immersed in an artificial world can be enhanced by auditory and other non-visual technologies.
• Networked applications allow for shared virtual environments.

Note that a virtual environment can represent any three-dimensional world that is either real or abstract. This includes real systems like buildings, landscapes, underwater shipwrecks, spacecrafts, archaeological excavation sites, human anatomy, sculptures, crime scene reconstructions, solar systems and so on. Of special interest is the visual and sensual representation of abstract systems like magnetic fields, turbulent flow structures, molecular models, mathematical systems, auditorium acoustics, stock market behaviour, population densities, information flows, and any other conceivable system including artistic and creative work of abstract nature. These virtual worlds can be animated, interactive, shared and can expose behaviour and functionality.

Let Us Summarize

1. Multimedia can be described as an integration of multiple media elements together to influence the given information so that it can be presented in an attractive and interactive manner.
2. Humankind developed text and symbols so that they could communicate. Writing helped humans to remember things for a much longer period than what is possible with the help of memory (brain). Text can be written using various text-editing and processing tools such as word processing software.
3. Graphics is regarded as the key building block for multimedia projects. It can be implemented in a multimedia project in various forms like images, charts, flowcharts, 2D/3D graphics and so on.
4. Audio is the most sensuous element of multimedia. It is a physical phenomenon to stimulate our senses of hearing. It involves transmission of mechanical vibration by an elastic medium that is capable of being detected by the human ear.
5. Video refers to the moving picture accompanied by sound such as a movie on television. It is an excellent form of conveying a message to a large audience, adds richness to content and enhances the user experience. Integrating video elements in a multimedia application provides a great deal of information in a small duration of time. There are three main types of video file formats: QuickTime, AVI and MPEG.
6. Animation is the process of sequencing still images in rapid succession to give the effect of live motion. The sequence of images is shown one after the other very quickly so that the human eye and brain blend the images to produce the effect of motion. It is of two types, namely, 2D and 3D animation.
7. Kinematics and morphing are the two most commonly used animation effects. Kinematics is the study of movement and motion of structures that have joints, such as a walking man. It requires calculating position, rotation, velocity and acceleration of all the joints. Morphing involves transformation of one image into another.
8. A multimedia system is a system capable of processing multimedia data and applications. It is characterized by the processing, generation, manipulation and rendition of multimedia information.
9. There are two types of compression techniques: lossy and lossless. Lossy compression creates a smaller file by discarding some of the original information about the image whereas lossless compression reduces file size without permanently discarding information from the original file.
10. Multimedia is used in various fields like education, entertainment, training, business and information kiosks.
11. Virtual reality can be described as an artificial environment that is created by using special computer hardware and software, which is presented to the user in such a manner that it appears and feels like a real three-dimensional world. To enter in virtual reality, a user wears special gloves, earphones and HMD, all of which receive input from the computer system.

Exercises

Fill in the Blanks

1. ........... constitutes an integration of multiple media such as text, graphics, audio, video and animation elements.
2. ................ ............... is the object in the text that allows jumping from one web page to another page at the same site or to another site on the Web.
3. ..................... means the removal of blank spaces from the front of the recording.
4. JPEG uses ..................... compression technique whereas PNG uses ..................... compression technique.
5. ....................... files are the Microsoft standard file format for storing waveform audio data.
6. The process of removal of extraneous noise that inevitably creeps into a recording is called .....................
7. ..................... is extremely high quality file format that delivers higher image resolution, picture quality, interlaced video format, multi-resolution scalability, and multi-channel audio features.
8. ..................... refers to the study of movement and motion of structures that have joints.
9. ..................... can be described as an artificial environment created from the computer hardware and software, presented to the user in such a manner that it appears and feels like a real environment.
10. The amount of data that can be transmitted from one computer to another in a given time frame is called .....................

Multiple-choice Questions

1. Text element of multimedia is predominant in .....................
   1. Newspaper
   2. Movie
   3. Radio
   4. None of these
2. Text that allows skipping from one web page to another page at the same site or to another site somewhere else on the Web at a click of a button is called .....................
   1. Normal text
   2. Animated text
   3. Hypertext
   4. None of these
3. Which of the following are the features of multimedia application?
   1. Use of digital technology
   2. Interaction from the user
   3. Integration of text, sound and video
   4. All of these
4. A flowchart is a kind of .....................
   1. One-dimensional graphics
   2. Two-dimensional graphics
   3. Three-dimensional graphics
   4. None of these
5. The process of removal of blank spaces from the front of the recording is called...........
   1. Splicing
   2. Morphing
   3. Equalizing
   4. Trimming
6. A high-quality file format that delivers better picture quality for the motion picture is.........
   1. QuickTime
   2. AVI
   3. JPEG
   4. MPEG
7. Technique that involves transformation of one image into another is called .....................
   1. Kinematics
   2. Compression
   3. Morphing
   4. Time stretching
8. The most appropriate form of graphics used for presenting facts and figure information is.......
   1. Flowchart
   2. Background
   3. Charts and graphs
   4. 2D graphics
9. A device having two miniature display screens and an optical system that channels the images from the screens into the user's eyes is called .....................
   1. HMD
   2. BOOM
   3. CAVE
   4. None of these
10. Which of the following image file format uses lossless compression?
    1. MPEG
    2. JPEG
    3. PNG
    4. None of these

State True or False

1. Graphics is one of the building blocks of multimedia.
2. The text which allows users to jump from one web page to another at a click of a button is called rich text.
3. Adobe Photoshop is an image editing software.
4. Music can be used to set moods and convey ideas to the user.
5. Trimming operation in sound files refers to the modification of the recording frequency content into brighter sound.
6. JPEG file format is used for creating video.
7. Morphing and Kinematics are the two most important animation techniques.
8. Lossy compression gives better image quality than lossless compression.
9. Virtual reality is an artificial environment, created by special hardware and software.
10. HMD stands for Head Mounted Display.

Descriptive Questions

1. What is multimedia? State the role of elements that together constitute multimedia.
2. Differentiate between normal and rich text.
3. What are the characteristics of virtual reality?
4. Explain some of the common uses of multimedia in various fields.
5. What is a multimedia system? Explain all desirable features of a good multimedia system.
6. How does the virtual reality system work? What components are used in the development of a virtual reality environment?
7. Explain the importance and role of animation in making a multimedia application.

ANSWERS

Fill in the Blanks

1. Multimedia
2. Hypertext
3. Trimming
4. Lossy, Lossless
5. WAV
6. Splicing
7. MPEG
8. Kinematics
9. Virtual reality
10. Bandwidth

Multiple-choice Questions

1. (a)
2. (c)
3. (d)
4. (b)
5. (d)
6. (d)
7. (c)
8. (c)
9. (a)
10. (c)

State True or False

1. True
2. False
3. True
4. True
5. False
6. False
7. True
8. False
9. True
10. True