Data Compression - Systematisation

---- Data Reduction ----

by T.Strutz

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Figure 5: Data Reduction Chart

Data Reduction comprises all methods, which reduce the irrelevant parts of the signal content resulting to changed signal information. This requires preparatively a separation of relevant and irrelevant components We can distinguish between quantisation, which decreases the resolution of the signal values, and sub-sampling decreasing the temporal or spatial resolution of signals. If any part of a compression system applies a data-reduction method, the compression algorithms is called "lossy" due to the fact that data reduction changes the digital information. Contrary to this, in "lossless" compression schemes quantisation and sub-sampling are not allowed.

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Strutz / 17.02.2003 Valid HTML 4.0!