The History of Data Compression

COMMANDER SAVES BUSINESS www.COMMANDER.COM PRES ENTS The HISTORY of DATA COMPRESSION MORSE CODE was introduced in telegraphy. Shorter CODE WORDS were used for common letters like 'e' and 't. 1838 1.0 INFORMATION THEORY 80.5 1940 was developed. This saw the EVOLUTION of many techniques of data compresslon. 0.5 1.0 Pr(X - 1) SHANNON-FANO It assigns codes to symbols in a given block of data based on the PROBABILITY of the symbol The Shannon-Fano coding algorithm 1949 was Introduced by CLAUDE SHANNON and ROBERT FANO. occurring. HUFFMAN CODING • Probability tree DAVID HUFFMAN came up with a new method whilst completing his 1951 PHD at MIT. While in Shannon-Fano coding the PROBABILITY TREE is built bottom-up, in Huffman coding it is bullt top-down. LZ77 ALGORITHM ABRAHAM LEMPEL and JACOB ZIV introduced the LZ77 algorithm, which was the first to use a dictionary to 1977 compress data. It used a DYNAMIC DICTIONARY called a sliding window. LZ78 ALGORITHM Lempel and Ziv published thelr LZ78 algorithm whlch also uses a dictionary. 1978 This algorithm generates a STATIC DICTIONARY. LZW ALGORITHM TERRY WELCH made changes which led to the Lempel-Ziv-Welch (LZw) algorithm. 1980 This became the most popular algorithm for many general purpose compression systems, and Is used in MODEMS, for example. DIGITAL IMAGES became so popular that standards for Image compression started evolving. LATE 1980 The TIFF FILE FORMAT was published in 1986 and is still used for high colour-depth images. LOW BIT-RATE AUDIO CODING German company FRAUNHOFER-GESELLSHAFT began researching high quality, low bit-rate audio coding. 1987 They almed to compress a CD-QUALITY song without affecting the sound. GIF CompuServe introduced the GRAPHICS INTERCHANGE FORMAT (GIF) format which used LZW data GIF compression provide an image format for their files. This replaced their RUN-LENGTH ENCODING format, which was black and white only. GIF can also be used to display ANIMATION DIGITAL VIDEO CODING THE FIRST truly practical digital video coding standard was Introduced by the International Telecommunication 1988 Union. This formed the basis for all subsequent VIDEO CODING STANDARDS MP3 Fraunhofer-Gesellshaft recelved a 1989 German patent for 'MP3'. They now license the PATENT rights to the audio compression technology. ZIP FILE FORMAT Phil Katz created the .ZIP file format, which supports lossless compression and permits a number of compression algorithms. The name .zip means 'to move at FAST SPEED *ZIP JPEG 1992 was created by the Joint Photographic Experts Group. The degree of compression can be adjusted, allowing a tradeoff between STORAGE SIZE and IMAGE QUALITY. GZIP FILE FORMAT LLD Queue RAW L2 Huffman was released and is based on the DEFLATE algorithm, which is a Encoder Encoder DATA combination of LZ77 and Huffman COMPRESSED LLD Queue DATA coding. DEFLATE was Intended as a replacement for LZW and other patented algorithms. LZ Encoder Huffman Encoder DECOMPRESSED DATA •Deflate diagram RAR ARCHIVE FILE FORMAT was released by Russlan software engineer, EUGENE ROSHAL 1993 The minimum size of an RAR file is 20 BYTES. PNG FILE FORMAT Version 1,0 of the PORTABLE NETWORK GRAPHICS (PNG) raster graphics file format was authored by a group of computer graphics experts and enthusiasts. While GIF has a limit of 256 colours, PNG is a LOSSLESS 1996 Image compression format. COMPRESSED FOLDERS 1998 MICROSOFT started to Include bullt-in .ZIP support under the name 'COMPRESSED FOLDERS'. SOURCES: http://inventors.about.com/od/mstartinventions/a/MPThree.htm http://www.ukessays.com/essays/information-technology/history-of-the-data-compression-information-tec hnology-essay.php http://www.leeeghn.org/wikvindex.php/History_of_Lossless_Data_Compression_Algorithms http://www.ou.edu/class/digitalmedia/articles/CompressionMethods_Gif Jpeg_PNG.html http://en.wikipedia.org/wiki/Data_compression http://www.makeuseof.com/tag/infographic-history-video-file-formats/ http://www.csi-India.org/c/document_library/get_file?uuld=cf4af2d1-5c7D-4afb-a615-089974dba6b3&grou pld=10157 A.