DATA COMPACTION

The reduction of the number of data elements, bandwidth , cost, and time for the generation, transmission , and storage of data without loss of information by eliminating unnecessary redundancy , removing irrelevancy, or using special coding . Note 1: Examples of data compaction methods are the use of fixed- tolerance bands, variable-tolerance bands, slope -keypoints, sample changes, curve patterns, curve fitting, variable- precision coding, frequency analysis, and probability analysis. Note 2: Simply squeezing noncompacted data into a smaller space, for example by increasing packing density or by transferring data on punched cards onto magnetic tape , is not data compaction. Note 3: Whereas data compaction reduces the amount of data used to represent a given amount of information, data compression does not.