필터 지우기
필터 지우기

denoising using wavelet

조회 수: 4 (최근 30일)
hajer
hajer 2011년 11월 25일
편집: Walter Roberson 2016년 9월 11일
How i can do denoising of 2-D signals with wavelet by using matlab cods ? plz help me :(

채택된 답변

Wayne King
Wayne King 2011년 11월 25일
편집: John Kelly 2014년 5월 27일
I'm not sure why your original post was about 2-D and it turns out that you have 1-D signals.
Yes, what you have done is basically correct. You could also use wden().
  댓글 수: 2
hajer
hajer 2011년 11월 25일
plz how i can differentiation between 1-D and 2-D
also , if i have signal extracted from ECG device and it mix from mother and fetus signal
is it 1-D or 2-D ???????
Sorry for the inconvenience
Wayne King
Wayne King 2011년 11월 25일
Hi, 2-D is an image, a function of two variables. ECG is 1-D signal. It is a function of one variable (time -- even though it is sampled).
If you have two ECG signals, you have two 1-D signals.

댓글을 달려면 로그인하십시오.

추가 답변 (2개)

Wayne King
Wayne King 2011년 11월 25일
Hi, You have a couple of options.
1.) use wavemenu. Enter wavemenu at the command line and then choose, Wavelet 2-D, or SWT Denoising 2-D. Starting in R2011b, you can generate MATLAB code for your denoising directly from the wavemenu GUI.
From the command line, you can use wavedec2 and wdencmp, for decimated 2-D Wavelet denoising, and swt2 and wthresh or stationary wavelet 2-D denoising.
There are some good User's Guide examples of using the GUI and generating MATLAB code for 2-D denoising here:
and here:
Note that the generated code in these examples also shows you how to implement 2-D wavelet denoising from the command line.
  댓글 수: 1
hajer
hajer 2011년 11월 25일
thanks very much Wayne King ....
if i have two mixed ecg signals
and i added some noise to signals
then i called ddencmp and wdencmp functions
like this
% load 2 ecg signals
x1 = repmat(ecg(50), 1, 8);
x2 = repmat(ecg(25), 1, 16);
%plotting commands
figure (1),
subplot(2,1,1),plot(x1)
title(strcat(['Original signals' ]));
subplot(2,1,2),plot(x2)
%mixed signal
s=[x1;x2];
A=randn(10,2);
mixed = A*s;
%Noise
noise = randn(10,length(mixed)).*0.18;
signalWithNoise=mixed+noise;
%----------------denoising------------%
[thr,sorh,keepapp] = ddencmp('den','wv',signalWithNoise);
xd =wdencmp('gbl',signalWithNoise,'sym10',10,thr,sorh,keepapp);
is denoising right or not ??

댓글을 달려면 로그인하십시오.


shivangi b
shivangi b 2016년 9월 8일
편집: Walter Roberson 2016년 9월 11일
sir,
for image de-noising using stationary wavelet transform and threshold techiques I have used
THR = wthrmngr('sw1ddenoLVL',METHOD,SWTDEC,SCAL)
command swtdec =db1,scal= 2 ,method ='rigsure'.
couldn't decompose the original image and hard and soft threshold used . plz replay me sir id:shivangisbv@gmail.com
  댓글 수: 1
Geoff Hayes
Geoff Hayes 2016년 9월 11일
As this isn't an answer to the posted question, please delete and post as your own question.

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Denoising and Compression에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by