Abstract

The one of the basic technologies of the multimedia are image, audio and video compression.It is necessary to code image and audio at the lowest possible data rates.The transmission and storage of information becomes costly as bandwidth cost money.The transmission and storage become cheaper if less data is used to represent image and audio.The signals plays an important role in our daily life ; examples are audio,speech, music, picture and video signals.A signal is a function of independent variables such as time, distance,position,temperature.A signal is is defined as any physical quantity that carries information which varies with other independent or a dependent variable.Image compression is minimizing the dimensions in bytes of a graphics file without degrading the standard of the image to an unacceptable level.The representation of information in compact form is called compression.The compression is the process used to reduce the bit rate for transmission or storage. While compressing it is also necessary to maintain acceptable fidelity or data quality.