2.11.2.8 wtdenoise(Pro)

Menu Information

Analysis: Signal Processing: Wavelet: Denoise

Brief Information

Remove noise using wavelet transform

Additional Information

This feature is for OriginPro only.

Command Line Usage

1. wtdenoise iy:=col(2);

2. wtdenoise iy:=col(2) type:=db2;

3. wtdenoise iy:=col(2) thrt:=sqtwolog level:=7;

4. wtdenoise iy:=col(2) thrt:=custom thrd:=30;

Variables

Display
Name
Variable
Name
I/O
and
Type
Default
Value
Description
Input iy

Input

XYRange

<active>

Specify the input signal

Wavelet Type type

Input

int

haar

Specify the wavelet type Option list

  • haar:Haar
    Haar wavelet
  • db 2:DB2
    Daubechies wavelet (N=4
  • db 3:DB3
    Daubechies wavelet (N=6)
  • db 4:DB4
    Daubechies wavelet (N=8)
  • db 5:DB5
    Daubechies wavelet (N=10)
  • db 6:DB6
    Daubechies wavelet (N=12)
  • db 7:DB7
    Daubechies wavelet (N=14)
  • db 8:DB8
    Daubechies wavelet (N=16)
  • db 9:DB9
    Daubechies wavelet (N=18)
  • db 10:DB10
    Daubechies wavelet (N=20)
  • b11:Bior1.1
    Biorthogonal (Nr=1, Nd=1)
  • b13:Bior1.3
    Biorthogonal (Nr=1, Nd=3)
  • b15:Bior1.5
    Biorthogonal (Nr=1, Nd=5)
  • b22:Bior2.2
    Biorthogonal (Nr=2, Nd=2)
  • b24:Bior2.4
    Biorthogonal (Nr=2, Nd=4)
  • b26:Bior2.6
    Biorthogonal (Nr=2, Nd=6)
  • b28:Bior2.8
    Biorthogonal (Nr=2, Nd=8)
  • b31:Bior3.1
    Biorthogonal (Nr=3, Nd=1)
  • b33:Bior3.3
    Biorthogonal (Nr=3 Nd=3)
  • b35:Bior3.5
    Biorthogonal (Nr=3, Nd=5)
  • b37:Bior3.7
    Biorthogonal (Nr=3, Nd=7)
Extension Mode ext

Input

int

periodic

Specify the end extension mode used in wavelet transform

Option list

  • periodic:Periodic
    The input signal will be viewed as periodic.
  • pad0:Zero -padded
    The data points outside the input range will be viewed as zeroes.
Output oy

Output

XYRange

<new>

Specify the output range See the syntax here.

Threshold Type thrt

Input

int

custom

Specify how to decide the threshold for truncating the detail coefficients of each level.

Option list

  • custom:custom
    The threshold is set using the variable thrd
  • sqtwolog:sqtwolog
    The threshold is computed from the length of detail coefficients
Thresholding Level level

Input

int

1

Specify the number of levels for which detail coefficients are to be thresholded. A large level will cause more noise to be removed; but unfortunately the probability that the useful signal is distorted will be larger, compared with a small level.

Threshold of every Level (%) thrd

Input

double

50.

Only available when threshold type is Custom. It specifies a threshold value, which will be used for discarding the detail coefficients for all levels.


Examples

1. To perform wavelet denoising using sqtwolog to determine the threshold, to XY data in columns 1, 2 of the active worksheet, use the script command:

wtdenoise (1,2) thrt:=1

2. To perform default wavelet denoising to active data plot in graph, activate the plot then use the script command:

wtdenoise

3. To perform wavelet denoising using a pre-saved theme file called Mytheme, type in the Command Window:

wtdenoise -t mytheme

More Information

For more information, please refer to our User Guide.


Related X-Functions

dwt, idwt, wtsmooth


Keywords:smoothing