Algorithms For Dummies

 

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Shrinking long sequences of identical bits: Compression uses a special 

code to identify multiple copies of the same bits and replaces those copies 

with just one copy, along with the number of times to repeat it. This option is 

very effective with images (it works fine with fax black and white images) or 

with any data that you can rearrange in order to group similar characters 

together (DNA data is one of this kind).

 

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Leveraging statistics: Compression encodes frequently used characters in a 

shorter way. For example, the letter E appears commonly in English, so if the 

letter E uses only 3 bits, rather than a full 8 bits, you save considerable space. 

This is the strategy used by Huffman encoding, in which you recreate the 

symbolic table and save space, on average, because common characters 

are shorter.