Multimedia
The term media refers to the storage, transmission, interchange,
presentation,
representation and perception of different information types
(data types) such
as text, graphics, voice, audio and video. The term
multimedia is used to denote
the property of handling a variety of
representation media in an integrated
manner. The phrase 'representation
media' is used because it is believed the
most fundamental aspect of
multimedia systems is the support for different
representation types. It is
necessary for a multimedia system to support a
variety of representation
media types. It is also important that the various
sources of media types are
integrated into a single system framework. Multimedia
is more than multiple
media. Multimedia adds interactivity to the combination of
text, graphics,
images, audio and video. Creating your own media is more
interactive than is
using existing content, and collaborating with others in the
creation of
media is still more interactive. Multimedia systems use a number of
different
media to communicate supplementary, additional or redundant
information.
Often this may take the form of using multiple sensory channels,
but it may
also take the form of different types of visual input - textual,
graphical,
iconic, animation and video. Multimedia - the combination of text,
animated
graphics, video, and sound--presents information in a way that is
more
interesting and easier to grasp than text alone. It has been used for
education
at all levels, job training, and games and by the entertainment
industry. It is
becoming more readily available as the price of personal
computers and their
accessories declines. Multimedia as a human-computer
interface was made possible
some half-dozen years ago by the rise of
affordable digital technology.
Previously, multimedia effects were
produced by computer-controlled analogue
devices, like videocassette
recorders, projectors, and tape recorders. Digital
technology's exponential
decline in price and increase in capacity has enabled
it to overtake analogue
technology. The Internet is the breeding ground for
multimedia ideas and the
delivery vehicle of multimedia objects to a huge
audience. While we have
treated various output media in isolation, it is clear
that interesting
issues emerge as they are combined in what is termed
multimedia. In this
sense, any computer application that employs a video disk,
images from a
CD-ROM, uses high quality sound, or uses high quality video images
on screen
may be termed a multimedia application. Such interfaces are
often
aesthetically appealing and, where high capacity storage devices such
as CD-ROM
are used, can provide effective interactions for the user by acting
as very
large databases or storehouses of information with dense but
easy-to-use
cross-referencing and indexing. Multimedia is all things to all
people. The name
can convey a highly specific meaning or less then nothing,
depending on your
audience. In fact, multimedia is a singular mix of
disparate technologies with
overlapping application in pursuit of a market
and an identity. We can describe
it as the seamless integration of data,
text, images and sound within a single
digital information environment.
Multimedia finds its worth in the field of
presenting information in a manner
that is intuitive and more natural then
traditional means. A multimedia user
interface must provide a wide variety of
easily understood and usable media
control tools. In addition, information views
need to be integrated with
structural views, since the viewing of information
will often alternate
moving through the structure by one means or another.
Interactive
Multimedia (IMM) is about empowering the user to explore new realms
by a
variety of pathways. It is an umbrella term for a range of videodisc,
compact
disc and computer-based systems that allow the creation, integration
and
manipulation of text, graphics, still and moving video images and sound.
The
computer elements of an IMM system have the capacity to: · Store,
manipulate
and present a range of information forms · Allow various forms
of
computer-based information to be accessed in linear and non-linear ways.
·
Provide graphics overlay and print out screen material. · Enable
learners to
work independently. · Provide feedback to the learner Interactive
multimedia
provides a powerful means of enhancing learning and information
provision. There
are however some cautions which need to be heeded if the
full potential of IMM
is to be realised. These can be seen listed below: ·
Lack of world standards ·
Technical problems · Platforms · Building
successful teams · Developmental
costs Interactivity means that the user
receives appropriate and expected
feedback in response to actions taken. It
is a two-way human-machine
communication involving an end-user and a
computer-based instructional system.
Users actively direct the flow and
direction of the instructional or information
programmes which, in turn,
exchange information with the viewers, processing
their inputs in order to
generate the appropriate response within the context of
the programme. The
basic elements of human interface design are now well
established. The user,
not the computer should initiate all actions. The user
accesses and
manipulates the various elements of the product by clicking on
buttons, icons
or metaphors with a mouse or other pointing device. Interface
design should
be consistent where appropriate and differentiated where needed so
the user
can rely on recognition rather than recall. The user should always be
given
immediate auditory or visual feedback. User activities should be broken
into
small steps where tasks are complex. The interface design should
be
aesthetically pleasing, appropriate to the content and suited to the
learner's
culture and prior knowledge. For designers of multimedia the main
design issues
are how to integrate the media and which media to use for
presenting different
kinds of information. The development of metaphorical
interfaces, direct
manipulation, graphical user interfaces (GUI's) and recent
advances in the field
of virtual reality allow users to control the system by
manipulating objects
such as icons, windows, menus and scroll bars. In well
designed Interfaces,
these objects are so selected and represented that users
can intuitively deduce
their meaning and their function in the system from
prior 'everyday knowledge'
and experience. Hypertext is a system for
presenting active text. The key
feature from the learner's point of view is
that the text has many nodes and
links, which allow them to determine their
own routes through the material.
Hypertext has many applications,
including use as a presentation medium for
information management and
browsing, providing access to information that the
public needs (such as
tourism information) and for various activities.
Hypermedia combines
aspects of hypertext and a variety of multimedia used in
some combination.
The branching structure of hypertext is used with multimedia
in order
to produce a system in which learners can determine their own paths
through
the medium. Hypertext is the process of linking concepts within
text
documents through the use of 'hotwords'. A hotword is an active word
within a
document that the user can click on to navigate to another part of
the project
or to initiate some form of interaction. However navigation by
hypertext can be
confusing, it can be easy for a user to become 'lost in
hyperspace'. After a few
clicks users can be so far from the original topic
that they become hopelessly
confused. Nearly all multimedia applications
include text in some form. Text and
the written language remain the most
common way of communicating information in
our society. The computer brings
extra power to text, not only by allowing you
to manipulate its size and
shape but also making it an interactive medium. The
ability to show moving
images using digital video can greatly enhance IMM
projects. Just as video
has a role in multimedia, sound also plays an important
part in a project. A
few carefully placed sounds can greatly enhance a project,
but a continuous
monologue can be highly distracting. With the text-to-speech
technology, the
computer interprets text and converts it into phonetic sounds in
much the
same way as a human would. Thus, the computer can read back any text
within
any program with reasonable fidelity. This feature is very useful within
an
IMM program because large amounts of text can be converted to audio
without
large sound files. A particular use of this technology is to offer
an
alternative for vision-impaired people. There are however, some
disadvantages to
computer generated speech. The speech can sound robotic
compared to human speech
and it lacks the variable information that can make
human speakers appealing.
Unlike print or graphics, animation is a
dynamic medium. We get a sense of
relative timing, position, direction and
speed of action. We need no captions
because the message is conveyed by the
motion and the scene. Simply put,
animation is the process of creating,
usually graphically a series of frames and
then having them display rapidly
to get a sense of movement. Video provides
high-speed information transfer
and shows temporal relationships. Video is
produced by successive capture and
storage of images as they change with time.
Two types of speech are
available for use by multimedia developers: digitised
and synthesised.
Digitised speech provides high quality natural speech while
synthesised
speech may not sound as natural as human speech. Even with
improved
techniques for generating speech, it is not incorporated into
multimedia
programs as often as it could be. This may be due to a lack of
understanding of
how high quality speech is produced. Multimedia interface
designers have
typically used a navigation/map metaphor, a menu/hierarchy
metaphor or a journal
(sequence) metaphor. An example of the first strategy
is the Virtual Museum,
produced by Apple Computer. Here the user accesses the
multimedia information by
navigating through the virtual museum, moving from
room to room by selecting
directions of movement. Examples of the second
strategy include on-line
encyclopaedias and electronic books where a table of
contents is used to
organise the material. It is helpful to view multimedia
applications as a
convergence of today's content and titles, such as movies
and books of today's
computer application programs, such as word processors
and of today's network
services. As an example a multimedia book should have
the following features.
Besides text, the book has other media that the
author created, including not
only text, graphics and images but also audio
and video to make the book's
content clearer or more enjoyable. Programs
should be built-in to help a user
navigate through the author's media.
Multimedia's driving technologies, mainly
digital electronics and fiberoptic
communications are making more and more
functions sufficiently economical for
consumers to use. Example applications
include: Desktop Video Conferences
with collaboration Multimedia
Store-and-Forward mail Consumer
Edutainment, Infotainmnet, Sociotainment Digital
Libraries Video on
demand Hybrid Applications IMM has many applications in
libraries. IMM can
bring knowledge in its entire media formats into condensed,
accessible forms
capable of being used for reference and educational
applications. On the
whole, within the library sector IMM is currently regarded
with some
ambivalence. Many library professionals look upon it as an
interesting
technology, but one that will require significant investment and
change if its
potential is to be fully realised. Possible barriers to the
effective adoption
of IMM by librarians may be cited as financial constraints
and a lack of
requisite resources resulting in a lack of opportunity to
become familiar with
the new and emergent systems; ingrained traditional
resistance to change; a
degree of uncertainty regarding the appropriateness
of the technology to various
applications; an inability to grasp the
significance of IMM and a lack of
experience, knowledge and skills in regard
to IMM among library professionals.
Example applications include the Book
House - a library system using hypertext
techniques to help users find books
without the limitations of traditional
information retrieval. The user
interface of the Book House is based on a
building like a real library with
the user being able to enter rooms filled with
children's books, adult books
etc. The system supports four basic search
strategies, using icons and
pictures to enable location of the books or topic
sought. Voice response and
voice recognition technologies could be used in a
library situation, this
could mean that merely speaking a unique book identifier
or name could
trigger the system into automatically filling in the remainder of
the
bibliographic or personal details relating to that item or
person.
Increasingly, multimedia systems will be developed with the aim
of allowing
non-textual information to be used directly, in a demonstrational
manner. Even
when text is present other media provide different additional
information. Also,
when dealing with multimedia, users are naturally disposed
to interact in ways
other than those developed for text. A first step to
giving the user the
impression that he/she is dealing directly with
non-textual material allows
database search on the basis of identifying
images that best suit the user's
purposes. An initial query that turns up a
large number of images can be refined
by allowing the user to point a few
images out of the set that contain items of
interest. The system can then use
the text descriptions attached to the chosen
images to form a new query and
offer a further set of possibly more relevant
images. My conclusion is that
design could benefit tremendously from open and
collaborative multimedia
research - not from relatively closed multimedia
packages.