Topic:Data compression

From Wikiversity

data compression is a process that make the volume of files lower. the most important methods are lossless lossy the difference between these methods is: in lossless comperssion method you don't lose any data but in lossy you may loss part of your data. the algorithm of lossless method is imagine we have a note, and in this the "tomorrow" word is repeated ten times, so we make a table with two columns, one column is for the real word and a column for the symbol word. now we put the word "tomorrow" in first column(real word) and put the symbol "F$3" in the second column(symbol) right beside the word "tomorrow"and in the note we put the symbol "f$3" where ever we saw the word "tomorrow" we delete it and put the symbol "F$3".when we're reading the file we put the word "tomorrow" where ever we saw the symbol "F$3"(how do we know what shall we put when we saw the symbol"F3$"? that's simple, from the table.).