3.2 Data Portability

Overview

Understand the need for data compression and software needed to compress/decompress data.

Identify common file types such as jpeg, mpeg, gif, txt, csv, rtf, MP3, MP4, MIDI, pdf, html, zip.

Data compression

• Using special software to reduce the size of a file. The file is then compressed. At the other end it then needs decompression software to read it.

• Examples of software include:– Rar– Winzip

File types

RTF Rich Text Format Allows users to transfer data between different applications. Opened using a variety of word processing applications.

TXT Text File Allows the transfer of text and numbers but will not hold the formatting used.

CSV Comma Separated Variable Uses commas to decide when the data is broken up into list/cells, rows. Imports files directly into a database or spreadsheet.

File types

JPEG Joint Photographic Experts Group

A compressed graphic format. Popular with web images.

MPEG Moving Picture Experts Group

A compressed file format for digital video.

GIF Graphic Interchange Format

A graphics file that supports compressed images.

File typesMP3 Compressed recordings

that leave out the noise not detectable by the human ear.

MP4 Commonly used to store digital video and digital audio streams.Can also be used to store other data. Allows streaming over the Internet.

MIDI Musical Instrument Digital Interface

A file extension used to store digital music.

File types

PDF Portable Document File Format

Used in the crossplatform documents created using the Adobe Acrobat software.

HTML Hypertext Markup Language

Associated with web page design.

ZIP Shows that it is a compressed file(s).

Acronyms

• jpeg• mpeg• gif• txt• csv• Rtf• MP3

• MP4• MIDI• pdf• html• Zip• ASCII

File extension Meaning Application

PICT

TIFF

ASCII

Complete the table for each of the following file extensions and add in two of your own.

Exercise

Research

• Choose one graphic• Save it as a bmp• Then save it as a jpeg• Compare how much memory each takes up