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Showing posts from November, 2009

synchronization

it is the coordinated ordering of events.
it means to control the flow of information data from one level to another in an orderly fashion with respect to time.
the occurrence of simultaneous event is known as synchronisation.dedicated devices and parallel computing are the parameters that leads to the synchronisation.
absolute synchronisation in multimedia communication system is different for different media, but it should not affect the presentation quality.
synchronisation events have real time deadlines.
failures to synchronise can be handled by methods like frame representation or skipping.

orchestration

delay, jitter, and errors are introduced during the transmission in a system is cumulative in nature which must be managed to achieve end to end quality of service(QOS).
the management of collection of resources manager to achieve end to end synchronisation is called orchestration.
QOS parameters are the fundamental units of orchestration.
the qos parameters which permit system wide orchestration is called QOS orchestration.

hypermedia

it is the application of multimedia retrival system where we can store the information(image, graphics, audio,vedio, animation).example:-www.(world wide web) it is the collection of webpage build by w3c consortium. http://www.sitename.com : colon to separate the protocol from the url locator. //directory structure(escape sequence). . used as separator FTP-file transfer protocol. features of hypermedia:- it has multiple media. it has limited interactivity. no synchronisation is required. on checking some words on the website we can go to the source website, where it is stored.
hyperlink:- it is a link to other websites or the other pages in the same website.
hypertext:- these are formatted text created by a language called h.t.m.l(hyper text mark up language). this text is basically used for the transfer of information on the internet.

types of multimedia

basically multimedia are of two types:-(i)linear multimedia:-it cannot be changed that is it doesn't allow us to change it as and when we want. for example:-animated mouse,animated movie,documentary (ii)non linear multimedia:-it can be used by the user by allowing them to change the contents. for example:-computer games.

Raster scanning process

the purpose of a video camera is to convert an image infront of camera into an electrical signal.an electrical signal has only one value(either on or off)at any instant of time and is one dimensional, but the image is two dimensional having many values at all the different positions in the image. conversion of 2-dimensional(2D) image to 1-dimensional electrical signal is accomplished by scanning that image in an orderly pattern called a Raster. with scanning, we move a sensing point rapidly over the image fast enough to capture the complete image, before it moves too much. as the sensing point moves the electrical output changes in response to brightness or colour of the image beneath the sensing point. the varying electrical signal from the senser represents the image as the series of values spread out in time. this is called a video signal.

colour video

color reproduction and display is different in between TV and computer, because computer monitor uses RGB component video i;e color is split into red, green and blue signals which are purer and more accurate than those scanned on TV monitor. *consequently the color used in graphics image created for computer video may display differently when the images transferred into NTSC transmission video. *indeed NTSC TV uses limited color palettes and restricted luminance(brightness levels and black levels). *some colors are generated by the computer that display fine color on RGB.the monitor may be illegal for display on NTSC TV broadcast. *most commercial broadcast facility and TV studios refuse to run programs that include illegal colors. *filters to convert illegal colors to legal colors are available in video and image editing processing application. the TV systems are designed to do particularly well on skin tones, not on hydrodynamical simulation. *very bright colors will vibrate distrac…

colour fundamentals

color is one of the most powerful elements in design, it has tremendous impact and expressive quality.*a color is described basically in three ways. (i)by its name(hue a property). (ii)how pure or desaturated it is(saturation level). (iii)its value or lightness. (a) HUE-hue is a term for the pure spectrum colors,commonly referred to by the "COLOR NAMES." *red, orange,yellow,green,blue an violet-all appear in the hue circles or color spectrum. *theoretically all colors can be mix from 3 basic hues known as, the primary colors(hue).
(b)saturation-saturation or purity refers to the intensity of a specific hue or color.
(c)lightness-value is defined as the relative lightness(tint), or darkness(shade) of a color.

Motion Picture Expert Grop

Motion Picture Expert group. -it is a full motion video.-the inter frame is of ratio 200:1. -the audio encoding ratio is of order 5:1. the decompression is done before the playback of the file. -the data is compressed to reduce the size of the source information. -it allows full motion media i,e audio and video. in inter frame each image is considered as still image. -mpeg contains two layers. (i)system layer.
(ii)compression layer.
*SYSTEM LAYER-it contains timing information to synchronize audio and video. *COMPRESSION LAYER-this layer is responsible for compressing of source data.