Multimedia Systems and Applications lecture 02.pdf

By Syed Imran Ali

By Syed Imran Ali

Subject : Multimedia Systems & Applications

controlled.  All multimedia components are integrated.  The interface to the final user may permit interactivity.  The information must be represented digitally.

By : Syed Imran Ali (MS / M.Phil)

systems must be Computer

Mohammad Ali Jinnah University, Karachi

 Multimedia

Subject : Multimedia Systems & Applications

By Syed Imran Ali

By : Syed Imran Ali (MS / M.Phil)

is used for  Producing the content of the information – e.g. by using the authoring tools, image editor, sound and video editor  Storing the information – providing large and shared capacity for multimedia information.  Transmitting the information – through the network.  Presenting the information to the end user – make direct use of computer peripheral such as display device (monitor) or sound generator (speaker).

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 Computer

device, such as microphone and camera is connected to and controlled by a single computer.  A single type of digital storage is used for all media type.  Video sequences are shown on computer screen instead of TV monitor. By Syed Imran Ali

Subject : Multimedia Systems & Applications

 Every

By : Syed Imran Ali (MS / M.Phil)

multimedia components (audio, video, text, graphics) used in the system must be somehow integrated.  Example:

Mohammad Ali Jinnah University, Karachi

 All



By Syed Imran Ali

Subject : Multimedia Systems & Applications



Level 1: Interactivity strictly on information delivery. Users select the time at which the presentation starts, the order, the speed and the form of the presentation itself. Level 2: Users can modify or enrich the content of the information, and this modification is recorded. Level 3: Actual processing of users input and the computer generate genuine result based on the users input.

By : Syed Imran Ali (MS / M.Phil)



levels of interactivity:

Mohammad Ali Jinnah University, Karachi

 Three

Subject : Multimedia Systems & Applications By : Syed Imran Ali (MS / M.Phil)

 Digitization

By Syed Imran Ali

: process involved in transforming an analog signal to digital signal.

Mohammad Ali Jinnah University, Karachi

TV signal, sound

 Digital

signal: a time-dependent or spacedependent sequence of values coded in binary format. (discreet value)

By Syed Imran Ali

Subject : Multimedia Systems & Applications



By : Syed Imran Ali (MS / M.Phil)

signal: a physical value which varies continuously with time and/or space.

Mohammad Ali Jinnah University, Karachi

 Analog

Subject : Multimedia Systems & Applications By : Syed Imran Ali (MS / M.Phil)

 A/D

By Syed Imran Ali

converter : Analog -> Digital  D/A converter : Digital -> Analog

Mohammad Ali Jinnah University, Karachi

Subject : Multimedia Systems & Applications By : Syed Imran Ali (MS / M.Phil)

By Syed Imran Ali

1. Sampling 2. Quantization 3. Code word

Mohammad Ali Jinnah University, Karachi

By Syed Imran Ali

Subject : Multimedia Systems & Applications

Analog values are generally captured only at regular time or space intervals.

By : Syed Imran Ali (MS / M.Phil)

consist of retaining only a discrete set of values from the continuous set of values of the analog signal.

Mohammad Ali Jinnah University, Karachi

 Sampling

Subject : Multimedia Systems & Applications

By Syed Imran Ali

By : Syed Imran Ali (MS / M.Phil)

process of converting a sampled signal into a signal which can only consist of discreet values.  E.g: only use positive and negative integers.

Mohammad Ali Jinnah University, Karachi

A

Subject : Multimedia Systems & Applications

By Syed Imran Ali

By : Syed Imran Ali (MS / M.Phil)

process of associating a group of binary digits, called a code word to every quantized value.  E.g: quantized value 18 is associated with binary code-word “00010010”.

Mohammad Ali Jinnah University, Karachi

A

Subject : Multimedia Systems & Applications By : Syed Imran Ali (MS / M.Phil)

By Syed Imran Ali

 Processing

 Transmission

 Storage

Mohammad Ali Jinnah University, Karachi



By Syed Imran Ali

Subject : Multimedia Systems & Applications



The same digital storage device can be used for all media The only difference lies in size requirement for each media. Images, sound and video require larger volumes than text.

By : Syed Imran Ali (MS / M.Phil)



Mohammad Ali Jinnah University, Karachi

 Storage

  

Digital signal is less sensitive to noise. Error detection and correction can be implemented Encryption of the information - easier

By Syed Imran Ali

Subject : Multimedia Systems & Applications



A single communication network supporting digital transmission can be used to transmit information in all media type. Benefits:

By : Syed Imran Ali (MS / M.Phil)



Mohammad Ali Jinnah University, Karachi

 Transmission



By Syed Imran Ali

Subject : Multimedia Systems & Applications



Editing : cut and paste function, mixing information from different media is possible Quality improvement : removal of noise or error (sound), image enhancement Recognition of the meaning of the information – image processing

By : Syed Imran Ali (MS / M.Phil)



Mohammad Ali Jinnah University, Karachi

 Processing

By Syed Imran Ali

Subject : Multimedia Systems & Applications

representation permits the storage of different information types on the same devices.  Information may also be transmitted over a single digital network.  When digitized, all form of information may be treated by computer programs, for editing, quality improvement, or recognition of the meaning of the information

By : Syed Imran Ali (MS / M.Phil)

 Digital

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Summary