Feature enhancement: normalizing



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Feature enhancement: normalizing

It is common for the high-frequency portion of a signal to be weaker (less energetic) than lower-frequency components. As a result, a common magnitude scale (contour lines on the maps above, or color scale on Fig.1) will poorly display the short-duration events in a signal. Normalizing each line of the map (fixed duration) so it has unit variance (in effect dividing the energy map by the mean energy spectrum) at each duration restores more details of small-scale activity (Fig. 24).




Figure 24: Normalized g2-wavelet map restores emphasis on short-duration events.




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Jacques Lewalle
Mon Nov 13 10:51:25 EST 1995