Data compression : Data compression Prepared by – Ravinder Singh
MIT081077 Graphics from - http://plus.maths.org/issue23/features/data/data.jpg Why Data Compression : Why Data Compression Definition
Reducing the amount of data required to represent a source of information.
Preserve the output data original to the input as much as possible.
Reduce the space required for the data storage.
Also reduce the time of data transmission over network.
SOURCES - www.data-compression.com/index.shtml Types of Compression : Types of Compression Lossless compression.
Basic principle of both :
Graphics from - http://img.zdnet.com/techDirectory/LOSSY.GIF Lossless Compression : Lossless Compression In this the compressing and decompressing algorithms are inverse of each other.
When data contains repeated strings then these can be replaced by special marker.
original data compressed data
Sources- www.data-compression.com/lossless.shtml 572744444444321333333333335278222222 5727#408321#3115278#206 Lossless (contd.) : Lossless (contd.) Statistical compression:
In this the short codes are used for frequent symbols and long for infrequent.
Three common principles are :-
1. Morse code.
2. Huffman encoding.
3. Lempel- Ziv -Welch encoding.
Extremely useful for sending video, commercial TVs and
30 frames in every second.
References - www.data-compression.com/lossless.shtml Lossy compression : Lossy compression Some data in output is lost but not detected by users.
Mostly used for pictures, videos and sounds.
Basic techniques are :
Referenced -http://searchciomidmarket.techtarget.com/sDefinition/0,,sid183_gci214453,00.html Transformation Quantisation Encoding decompress compress Latest Developments : Latest Developments Fathom 3.0
Developed by Inlet technologies in cooperation with Microsoft and Scientific Atlanta.
Work with media files for mobiles, portable, web and high definition.
Geolocation data compression.
Used for compress the data between sensors.
For navigation the target and its location.
Sources- http://localtechwire.com/business/local_tech_wire/wire/story/1276887/ Future : Future Robust digital compression.
Just need 1mb additional software on web client.
Used smarter algorithms.
Massive acceleration of mirror world and high definition video stream.
Sources- http://www.futureofgadgets.com/futureblogger/show/1730 Annotated Bibliography : Annotated Bibliography I choose the text from –
because it fulfills mine requirement for the topic.
I choose the graphics from –
because it clears the situation which I want to explain.