7

Multimedia Essentials

1. What is multimedia?

Ans.: 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, be it newspaper or radio or television. With the development of computers, presenting data has taken an entirely new meaning. Multimedia is a computerized method of presenting information by combining audio, video, graphics, texts, and/or animations 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 some of the following features:

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

2. What are the building blocks of multimedia? Explain.

Or

Discuss the elements that together constitute multimedia.

Ans.: As we know, 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. The various elements that together constitute multimedia are text, graphics, audio, video, and animation.

Text

It is the on-screen display of words and is the base of most applications. 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). Words and symbols in any form, spoken or written, are the most common means of communication. 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. It acts like electronic footnotes and assists in navigating through all the information. Files may contain raw text or formatted text. For example, hypertext markup language (HTML), a program language source (C and Pascal), or rich text format (RTF) are some file formats for text files that include formatting like different font styles, typefaces, etc. The basic storage of text is 1 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. Text can be written using various text editing and processing tools such as Microsoft Word and Word Perfect where text file can be developed and later imported into the multimedia authoring tools to integrate with other media elements.

Graphics

It is a generic term used to describe the pictorial representation of data. When one talks about graphics, we generally tend to refer those pictorial representations that are created by the 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), but graphics are usually editable or revisable (unlike images). Generally, graphic input devices include keyboard, mouse, trackball, or light pens. It is said that a picture is worth a thousand words, so adding a graphic element into a text-based document can change the user's perception towards the document. The 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 multimedia project, various images are captured from different sources like scanners, digital cameras, and through the Internet. Once the images are transformed into digitized form, they can be edited and modified using image-editing softwares: Adobe Photoshop, Corel Draw, and Freehand.

Audio

It means the sensation resulting from the 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 the transmission of mechanical vibration by an elastic medium that is capable of being detected by the human ear. Computers and digital technology have changed the face of music industry. Today, digital music is used to produce special effects in televisions, films, recording studios, and games. Music and sound effects not only add interactivity with the user but also play with the user's perception and emotions. Audio can also be used to provide a sense of place or mood as done to perfection in the game. 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. 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. Moreover, sounds can be embedded into a web page and can be played.

Video

It 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 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. 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.

Animation

It 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 then to try to explain it. It 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 one just changes slightly the location or shape of an object rapidly enough, the eye will perceive the changes as motion. 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.

3. Describe the different modes of presenting graphics.

Ans.: In today's challenging world, 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 various modes:

	Background: It 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 background should be more animated and colourful.
	Two-dimensional (2D) graphics: Usually, when one is looking at a computer screen, then he/she is looking at a 2D 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: A 3D image contains information about the scene in three dimensions (x, y, and z coordinates). However, these 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.
	Flowcharts: The use of the 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. They are also used for representing 2D graphics.

4. What are the basic sound-editing operations used in multimedia?

Ans.: Audio files can be manipulated to produce the desired output using various sound-editing operations. The basic operations are as follows:

	Trimming: To remove blank spaces from the front of the recording.
	Splicing and assembly: To remove extraneous noise that inevitably creeps into a recording.
	Volume adjustment: To provide consistent volume level for different recordings in a single sound track.
	Format conversion: To convert audio files into different formats.
	Equalization: To modify a recording frequency content to brighter sound.
	Time stretching: To alter the length of a sound file.
	Reversing sound: To reverse all or small portions of a digital recording.

5. Discuss the advantages of animation in multimedia.

Ans.: Animation is a powerful tool capable of communicating complex ideas by using computer graphics. It offers the following various advantages:

	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 change 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 2D, users can never get a full understanding of a 3D structure by a single illustration, no matter how well-designed. Animation can be used to emphasize the 3D 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.

6. Explain the various file formats used for multimedia data.

Ans.: Multimedia data and information must be stored in a disk file using some file formats. Multimedia formats, however, are much more complex than most other file formats because of the wide variety of data they store. Such data include text, image, audio, and video data. Therefore, there are various types of file formats used for multimedia data. Some of them are listed in Table 7.1.

Table 7.1 File Formats Used for Multimedia Data

 

Multimedia Data	File Formats
Audio	MIDI (Musical Instrument Digital Interface), WAV or WAVE (Waveform Audio Format), AIFF (Audio Interchange File Format), MP3, FLAC (Free Lossless Audio Codec), and Au
Video	QuickTime, AVI (Audio Video Interleave), MPEG (Moving Picture Experts Group), Flash video, WMV (Windows Media Video), ASF (Advances Streaming Format), 3GP, and Real Media
Images	GIF (Graphics Interchange Format), PNG (Portable Network Graphics), JPEG (Joint Photographic Experts Group), TIFF (Tagged Image File Format), BMP (Bit mapped), TGA (Truevision Graphics Adapter), PCX (Personal Computer eXchange), and EXIF (Exchangeable Image File Format)

 

7. What is a multimedia system? Explain all desirable features of a good multimedia system.

Ans.: 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. Thus, permanent storage is required to keep digitized information for the future retrieval and use. Moreover, multimedia also requires a large amount of the computer's main memory and large amount of bandwidth when distributed on a network. 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, large cache memory is also required of Level 2 and 3 hierarchies for efficient management.
	Operating system: Every multimedia system requires a special operating system that allows access to 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, etc.
	Software tools: User-friendly software tools are needed to handle media and design, to 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 I/O devices: Efficient I/O 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 (24X or higher), keyboard, 3-button scrollable 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.
	Network support: In a business conference, where a multimedia presentation is on, one may require associated peripherals connected to a main computer via communication devices (modems, hubs, etc.) to carry out the supportive role in running an application.

8. Write a short note on data compression. Illustrate lossy and lossless techniques with examples.

Ans.: 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 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, one cannot recover all of its original data from the compressed version. Examples of lossy compressed files are JPEG image files and MPEG video files. On the other hand, in lossless compression technique, the size of the file is reduced without permanently discarding any information of the original data. On decompressing, 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 ZIP tool.

Let us take an example to illustrate both the compression techniques. Suppose one is having two cups, one of 200 ml capacity (filled with water) and the other of 100 ml capacity (empty). Now he/she pours water into the 100 ml cup and throws away the rest. This is lossy compression because he/she has kept only the necessary data and thrown away unimportant data. Now if one wants to fill the 200 ml cup again with water from the 100 ml cup (recreating the original image), then he/she will find that the cup will not be filled because he/she has 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, one can easily 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.

9. Explain different multimedia applications of computer.

Ans.: The growing technology of the computer's hardware and software, to hold several types of media, has made multimedia suitable for a wide range of applications and users. Some of the areas where the use of multimedia applications has replaced the conventional system with new technology are education, entertainment, training, business, and multimedia interactive kiosks.

Education

Multimedia has the ability to accommodate different learning styles and can present material in a non-linear manner. It is motivating, highly interactive, and can provide feedback and evaluate skills. It acts as a helping tool for teachers as they can enhance their own teaching approach and moreover, they also find these tools appealing because of their ease of use and effective way of expressing information. 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. It 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.

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 too many interactive entertainment means games. 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, it provides fast action, vivid colours, 3D animations, and elaborate sound effects that are essential to entertainment. Nowadays, multimedia is extensively being used in the field of television broadcasting and movies. For example, while watching a live match on television, replays, slow motion, charts analysis, and other statistical information are common. These kinds of integrations on the sports make a novice understand and envisage the sports in a better way.

Training

In a corporate world, many multinational organizations invest huge sums of money in providing training to their staff members and employees. In traditional method of training, a reputed organization sends a group of trainers with necessary training tools and equipments to different centres across the world that incurs heavy expenses related to travel, food, salaries, etc. But in the case of multimedia-based training, 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. Thus, 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. 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 example, NASA uses multimedia extensively for flight control training for astronauts.

Business

One of the biggest users of multimedia is business organizations. As businesses have to communicate with the outside world, multimedia offers a wide variety of options for business presentations, marketing, and sales. It 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. For example, auto manufacturers like Nissan provide interactive test drives of new vehicles on the Web or on CD.

The 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 the multimedia application as a tool for conducting presentations, training sessions, marketing, advertising, and communications via videophone in running a business has made awesome changes on the style of carrying out business. Its widespread use in training programmes 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 and a security personnel can learn to tackle a bank robbery through simulation. The multimedia technology marked its beginning with application in advertising industry. Its power to boost communication on an affordable cost opened the way for the marketing and advertising personnel. Almost all the 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.

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. Some of the common services provided by the kiosk include search for necessary information, performing financial transactions, taking online shopping orders, and many more. These kiosks are located near the 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 the printed copy of the information. For example, a kiosk on the 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 different destinations, etc.

10. What do you mean by virtual reality? Discuss some of its characteristics.

Ans.: 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 3D world. The original term for virtual reality is immersive virtual reality which means the user becomes fully immersed in an artificial, 3D world that is completely generated by a computer. It is used in health care and mass entertainment. However, virtual reality systems require very expensive hardware and software and are confined mainly to research laboratories. It also requires tremendous computing power to be lifelike. Some of its characteristics are presented as follows:

	Head-referenced viewing provides a natural interface for navigation in the 3D 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 the 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.

11. What are the devices used in the development of a virtual reality environment? How does this system work?

Ans.: In virtual reality, cyber space is made up of thousands of geometric objects and points plotted in a 3D 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): It 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 glove: It is equipped with sensors that sense the movements of the hand and interfaces those movements with a computer. It is 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: It gives the wearer of this special headgear and gloves the interactive sensory experience that feels like an alternative to real-world experiences.

To enter in the virtual reality environment, a user wears special gloves, earphones, and HMD, all of which receive input from the computer system. 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. For example, the HMD tracks how the eyes move and respond accordingly by sending new video input.

Multiple-choice Questions

1.  Text element of multimedia is predominant in ___________.

(a) Newspaper

(b) Movie

(c) Radio

(d) 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 ___________.

(a) Normal text

(b) Animated text

(c) Hypertext

(d) None of these

3.  Which of the following are the features of a multimedia application ___________?

(a) Use of digital technology

(b) Interaction from the user

(c) Integration of text, sound, and video

(d) All of these

4.  A flowchart is a kind of ___________.

(a) One-dimensional graphic

(b) Two-dimensional graphic

(c) Three-dimensional graphic

(d) None of these

5.  The process of removal of blank spaces from the front of the recording is called ___________.

(a) Splicing

(b) Morphing

(c) Equalizing

(d) Trimming

6.  A high-quality file format that delivers better picture quality for the motion picture is ___________.

(a) QuickTime

(b) AVI

(c) JPEG

(d) MPEG

7.  AVI stands for ___________.

(a) Audio video interchange

(b) Audio video interval

(c) Audio video interleave

(d) None of these

8.  The most appropriate form of graphics used for presenting facts and figure information is ___________.

(a) Flowchart

(b) Background

(c) Charts and graphs

(d) 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 ___________.

(a) HMD

(b) BOOM

(c) CAVE

(d) None of these

10.  Which of the following image file format uses lossless compression?

(a) MPEG

(b) JPEG

(c) PNG

(d) None of these

Answers

1. (a)

2. (c)

3. (c)

4. (b)

5. (d)

6. (d)

7. (c)

8. (c)

9. (a)

10. (c)