关于多小波去噪MATLAB程序

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Press the "Start" button to see a demonstration of

denoising tools in the Wavelet Toolbox.

This demo uses Wavelet Toolbox functions.

% Set signal to noise ratio and set rand seed.

sqrt_snr = 3init = 2055615866

% Generate original signal and a noisy version adding

% a standard Gaussian white noise.

[xref,x] = wnoise(3,11,sqrt_snr,init)

% Denoise noisy signal using soft heuristic SURE thresholding

% and scaled noise option, on detail coefficients obtained

% from the decomposition of x, at level 5 by sym8 wavelet.

% Generate original signal and a noisy version adding

% a standard Gaussian white noise.

lev = 5

xd = wden(x,'heursure','s','one',lev,'sym8')

% Denoise noisy signal using soft SURE thresholding.

xd = wden(x,'rigrsure','s','one',lev,'sym8')

% Denoise noisy signal using fixed form threshold with

% a single level estimation of noise standard deviation.

xd = wden(x,'sqtwolog','s','sln',lev,'sym8')

% Denoise noisy signal using fixed minimax threshold with

% a multiple level estimation of noise standard deviation.

xd = wden(x,'minimaxi','s','sln',lev,'sym8')

% If many trials are necessary, it is better to perform

% decomposition one time and threshold it many times :

% decomposition.

[c,l] = wavedec(x,lev,'sym8')

% threshold the decomposition structure [c,l].

xd = wden(c,l,'minimaxi','s','sln',lev,'sym8')

% Load electrical signal and select a part.

load leleccumindx = 2600:3100

x = leleccum(indx)

% Use wdencmp for signal de-noising.

% find default values (see ddencmp).

[thr,sorh,keepapp] = ddencmp('den','wv',x)

% denoise signal using global thresholding option.

xd = wdencmp('gbl',x,'db3',2,thr,sorh,keepapp)

% Some trial examples without commands counterpart.

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 5

% [xref,x] = wnoise(1,11,sqrt_snr,init)

% Some trial examples without commands counterpart (more).

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 4

% [xref,x] = wnoise(2,11,sqrt_snr,init)

% Some trial examples without commands counterpart (more).

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 3

% [xref,x] = wnoise(3,11,sqrt_snr,init)

% Some trial examples without commands counterpart (more).

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 3

% [xref,x] = wnoise(3,11,sqrt_snr,init)

% Some trial examples without commands counterpart (more).

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 3

% [xref,x] = wnoise(3,11,sqrt_snr,init)

% Some trial examples without commands counterpart (more).

% Rand initialization: init = 2055615866

% Square root of signal to noise ratio: sqrt_snr = 3

% [xref,x] = wnoise(3,11,sqrt_snr,init)

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