Introduction to Multimedia Systems Lecture no 1 By

Introduction to Multimedia Systems Lecture no. 1 By Mr. Bilal Ahmad

Introduction to Multimedia � We perceive the universe through our senses. � Sight and hearing are brought into play as soon as we interact with the surroundings. � Our sensory organs send signals to brain. � Brain constructs an interpretation of this interaction. � The process of communication is dependent to our understanding of senses. � In General the more information that is perceived by the receiver, the more likely it will be an effective communication.

Introduction (Continued) � Example is that you are talking to a friend on telephone or you are sending texts as well as pictures. � The more information you send the greater will be the impact of your communication. � There has been a phenomenal growth/ development in the technologies to send more information.

Introduction (Continued) � The development of computers are also going in the same way. � Earlier the computer was capable to give simple text as an output, now you can get sound, pictures and more. � We define digital multimedia as a combination of text, graphics (still and animated), sound and motion video delivered to you by a computer. � The computer is an intrinsic part of multimedia. � All these elements are either computer generated or transmitted through a computer.

Application of Multimedia Systems � The development of powerful multimedia computers and the evolution of the internet have led to an explosion of applications of multimedia worldwide. � Multimedia systems are used in educations, in presentations as information kiosks. In the gaming industry. � In fact multimedia systems have applications all over in businesses, education, at home, at public places, at almost everywhere.

Meaning of Multimedia � The world multimedia is a combination derived from multiple and media. � The world medium means a transmission channel. � Note that media is plural and medium is singular. � For example sound is travelled through the medium of air and electricity via the medium of wires.

Multimedia Explained � Similarly poetry can be considered a medium of transmitting our thoughts. Painting is a medium for conveying what we observe. � Multimedia is also a medium. To use it effectively we need not only to understand how to create specific elements of multimedia, but also to design a multimedia system so that our communication is conveyed effectively. � This course will provide you two dimensions. One to design a multimedia system and other to design multimedia system for the multimedia information.

Elements of Multimedia � Consists of several elements such as sound, graphics, texts and video. � First element we consider is sound. Audio is slightly different from sound. Does anyone knows the difference between an audio and sound. � Audio is one the most appealing elements of any successful multimedia presentations. � It can set as well as disturb the mood. � It can be used to catch the interest and alert the audience. � The audio that appears in the multimedia presentations are of two types. Either computer generated or recorded and converted into digital format.

Graphics � Perhaps the most important element of the multimedia is the graphic element. � Information communicated through pictures is easier to understand to retain. � It can be still or animated. 2 D or 3 D, photographs or paintings etc. or it can appear as objects around us.

Text � Computer generated text is another example of multimedia. � A few words appearing in a predominantly graphic multimedia system can have a powerful effect. � Text and art can be effectively used to be mixed together for a nicer impact.

Video � Finally video is another element of a multimedia system. � Obviously video and audio are closely related and together they are the most effective means of communication that can be a part of the multimedia system.

Mass Media Versus Multimedia � Recall that the computer is an intrinsic part of multimedia. � Thus all elements of a multimedia have to be in a digital format. � In contrasts other multiple media such as TV Programs and films are analog in nature. � It is important to understand what is the difference between the two formats.

Mass Media Versus Multimedia � First there is a difference between a discrete and continuous. � Consider a line segment connecting two points. There is an infinite number of points on any line segment. � However when we wish to draw a line segment on a screen connecting two points we will be able to draw an infinite number of points because of the number of pixels on the screen is finite. � Only a finite number of pixels have to be colored black on a white screen to draw a line segment. � In other words we can say that the line segment is continuous and the line made on the computer screen is discrete.

Mass Media Versus Multimedia � However since the pixels on the screen are very close to each other, our eyes cant tell the difference. � So a continuous line is perceived. � Thus analog are continuous and digital are discrete. � For example the trees and plants we see around are continuous but there digital pictures are forced to be discrete.

Why to have multimedia on digital format? � Our consequence to have all multimedia elements to be in a digital format is that we need special hardware and software to convert analog to digital format. � For example we may shoot a video to incorporate in our multimedia project, but we need some special hardware and software to convert it as well as software to edit it. � Moreover multimedia systems takes a lot of space. � Different techniques are used to compress the data.

Compression example � For example to compress a music file a compression mp 3 technique is used. � We use mp 3 encoder. � To play we need the appropriate software that can play mp 3 music. And of course a multimedia computer/ mp 3 player. � In addition we need a special software to edit mp 3 files.

The Main screen of a Multimedia Product

Interactivity � In a multimedia system, if the user has the ability to control what elements are delivered and when, the system is called an interactive system. � Traditional mass media include television, film, radio and news papers. � Since the communication processes are one way, originating from a source and being delivered to a mass audience. � These technologies also combine audio, video, graphics and texts but in a way that is inflexible.

Interactivity Continued � For example a film has a predefined beginning, middle and end, irrespective of the audience watching it. � With the power of the computer, the same media could be manipulated with the audience. � In this the audience does not need to remain passive. They become the user of the system. � The key difference between mass media and multimedia is the shift from the audience to the users/ one way communication to be directed two way.

Interactivity � How to interact with the system is dependent on the system designer. � Do you need a mouse, keyboard, navigation panel etc. � One important thing is that well designed products always give feedback to the users once the user interacts with the system.