Data Compression Lec #1- 2018

Introduction
The last decade we have been witnessing a transformation—some call it a revolution—in the way we communicate, and the process is still under way. This transformation includes the ever-growing Internet; the explosive development of mobile communications; and the ever-increasing importance of video communication. Data compression is one of the enabling technologies for each of these aspects of the multimedia revolution.

So, what is data compression, and why do we need it? Most of you have heard of JPEG and MPEG, which are standards for representing images, video, and audio. Data compression algorithms are used in these standards to reduce the number of bits required to represent an image or a video sequence or music.

Data Compression
Data compression for (image, audio, video, text, or graphic) is the art or science of representing information in a compact form to reducing the size of the data. The primary goal of data compression is to reduce the file size. Compression is used just about everywhere for several reasons:

1) To save space when storing it.
2) To save time when transmitting it.

The task of compression consists of two components, an encoding algorithm that takes a message and generates a “compressed” representation and a decoding algorithm that reconstructs the original message or some approx¬imation of it from the compressed representation.