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w1threshold

$ \bigcirc$Name


w1threshold Thresholding of a 1D-Wavelet Transform




$ \bigcirc$Command Synopsis


w1threshold [-P P] [-T T] [-D D] [-M M] [-s] [-o] in out



-P P : Percent of coefficients to threshold

-T T : Threshold to use (needed if no -P neither -D)

-D D : Use Donoho threshold to denoise signal with additive gaussian noise of the given standard deviation

-M M : Output mask in the signal M (1 |  -1=coeff.kept, 0=coeff.thresholded)

-s : Soft thresholding (default is hard thresholding)

-o : Output threshold used

in : Input wavelet transform

out : Output thresholded wavelet transform




$ \bigcirc$Function Summary


void w1threshold (P , T , D , s , o , M , in , out )

float *P ;

float *T ;

float *D ;

char *s ;

char *o ;

Fsignal M ;

Wtrans1d in ;

Wtrans1d *out ;




$ \bigcirc$Description


This module thresholds a 1D wavelet transform so that a wavelet denoising can be performed using the scheme wavelet transform $ \rightarrow$ thresholding $ \rightarrow$ inverse wavelet transform. See [DJ94] and [Don95] for the theory of wavelet thresholding.

In addition, a mask that gives the location of coefficients that have been thresholded (and the ones that have been kept) can be generated. Such a mask is needed to perform restoration using TV-minimization method, see module stvrestore and user's macro Swtvdenoise for more about that.




$ \bigcirc$Version 1.0


Last Modification date : Thu Apr 3 16:57:02 2003


$ \bigcirc$Author


Jacques Froment






next up previous contents index
Next: biowave1 Up: Reference Previous: Swtvdenoise   Contents   Index
mw 2004-05-05