CHAPTER – 1 Introduction: Multimedia: Multi means: - many, much, multiple Medium means: - An intervening substance through which something is transmitted or carried on. A means of mass communication such as news paper, Television and so on. - Multimedia is woven combination of text, graphics, art, sound, animation, video and other kinds of elements. Multimedia is an inter-disciplinary subject because it involves a variety of different theories and skills. These includes – - Computer Technology, Hardware and software - Art and design, literature and presentation skills. - Application domain knowledge - - Multimedia means from the user’s perspective, that computer information can be represented through audio and/or video, in addition to text, image, graphics and animation. The integration of these media into the computer provides additional possibilities for the use of computational power currently available (example, for interactive presentation of huge amount of information). Further more, these data can be transmitted through computer telecommunication networks, which implies applications in the area of information distribution and cooperative work. Application: - Education - Training - Entertainment - Advertisement - Presentation - Image Processing Medium: In general, one describes medium as means for distribution and presentation of information. Example, text, graphics, speed and music We can classify media according to – - Perception - Representation - Presentation - Storage - Transmission - Information Exchange
The Perception Medium: - Perception media help humans to sense their environment. - The perception of information occurs mostly through seeing or hearing the information. - There is a primary difference between seeing or hearing information when using a computer. For the perception of information through seeing, the visual media such as text, image and video are used. For the perception of information through hearing, auditory media such as music, noise and speech are relevant. The Representation of Medium: - Representation media are characterized by internal computer representation of information. - Various formats are used to represent media information in a computer. Example, A text is character is coded in ASCII or EBCDIC code. - Graphics are coded according to CEPT or CAPTAIN video text standard. - An audio stream can be represented using a sample PCM (Pulse Code Modulation). - An image can be coded as a facsimile or in JPEG format. - A combination of audio/video sequence can be coded in different standard formats. (Example, PAL, SECAM, NTSC) and stored in the computer using MPEG format. The Presentation Medium: - Presentation media refer to the tools and devices for the input and output information. - The media Example, paper, printer and screen are used to deliver the information by the computer (output media) keyboard; mouse, camera and microphone are the input media. The Storage Medium: - Storage media refers to a data carrier, which enables storage of information. However, the storage of data is not limited only to the available components of a computer. - Microfilms, floppy disk, hard disk, pen drive, CD-ROM, DVD, zip disk are examples of storage media. The Transmission Medium: - The transmission medium characterizes different information carries that enable continuous data transmission. - Information is transmitted over networks, which use wire and cable transmitted, such as coaxial cable, fiber optic as well as free air space transmission, which is used for wireless traffic (example, satellite, microwave, Radio link and so on). The Information Exchange Medium: - The information exchange medium includes all information carrier for transmission i.e. all storage and transmission media. - Information can flow through intermediate storage media, where the storage medium is transported outside of computer networks to the destination,
through direct transmission using computer networks or through combined usage storage and transmission media (example, electronic mailing system). Representation values and Representation space: The media appeal to the human senses. Each medium defines representation values and representation spaces, which involve the five senses. - Examples of visual representation spaces are paper or screen. During a computer-controlled slide show with simultaneous projection of the computer screen content, the whole movie counts as a representation space. - Representation values determine the information representation of different media: while the text medium visually represents as a sentence through a sequence of characters, this sentence will be represented by the speech medium in the form of pressure wave. Some representation values are selfconfined by their media. Example temperature, taste and smell - Representation values can be considered as a continuous or a sequence of discrete values. - Characters of a text and audio sample values in electronic form are sequences of discrete values. Representation Dimensions: - Each representation spaces consist of one or more representation dimensions. A computer screen has two spatial dimensions, holography and stereophony. - Time can occur inside each representation, space as an additional dimension. - Media are divided into two types with respect to time in their representation space. (1) Some media, such as text and graphics are time-dependent. Information in these media consist exclusively of a sequence of individual elements or a continuous without a time component. Such media are known as timeindependent (or discrete). (2) The values of the other media such as sound and full motion video change overtime. Main properties of a Multimedia System: Multimedia System (Definition): A multimedia system is any system, which supports more than a single kind of media. A multimedia system distinguishes itself from other systems through several properties. The main properties are: (1) Combination of media (2) Media-Independent (3) Computer Control and Integration Combination of media: - A sample text-processing program with incorporated images is often called a multimedia application because two media are processed through one program. In multimedia both continuous and discrete media are utilized. Media-Independent: - An important aspect of different media is their level of independence from each other. In general, there is a request for independent of different media, but multimedia may require levels of independence.
- - One the one hand, a computer controlled video recorder stores audio and video information, but there is an inherently tight connection between the two types of media. Both media of the tape. One the other hand, for the purpose of presentations, the combination of DAT (Digital Audio Tape) recorder signals and computer available text satisfies the request for media-independent. Computer Supported Integration: - The media-independence pre-equisetic provides the possibility of combining media in arbitrary forms. Computers are ideal tool for this purpose. - The system should be capable of computer controlled media processing. Moreover, the system should be programmable by a system programmer or even a user. - Simple i/p or o/p of different media through one system (example, A video recorder) does not satisfy the requirement for a computer-controlled solution. - Computer controlled data of independent media can be integrated to accomplish certain functions. Example timing, spatial and semantic synchronization will be included. - An integrated multimedia system i.e. simply put in such systems, everything can be presented with video and sound that is presented with text and graphics today. Multimedia and Personalized Computing: In 1967, Nicholos Negroponte formed Architecture Machine Group in the Architecture department at MIT. Although the initial goal was to use computers for Architectural design; a new focus developed that of making computers easier to use. The major uses are: (i) Spatial Data Management System (SDMS) (ii) Movie, Maps and Surrogate travel (iii) The Electronic Book (iv) Formation of MIT lab i. Electronic Publishing ii. Film and video iii. Visual language workshop iv. Electronic music v. Spatial imaging and photography vi. Learning and Epistemology (destructive) vii. Movies for future viii. Advanced Television Research ix. Speech Processing x. Human – Machine Interface Group Data Stream Characteristics: In distributed multimedia systems, data of discrete and continuous media are transmitted and information exchanges take place. Moreover, in each digital system, transmitted information is divided into individual units (in general, packets) and subsequently sent away from one system (source) to another system (Destination). - The source and destination can be located at either on the same computer or on different machines.