wthrmngr :: Functions (Wavelet Toolbox™)

wthrmngr

Purpose

Threshold settings manager

Syntax

```
THR = wthrmngr(OPTION,METHOD,VARARGIN)
```

Description

THR = wthrmngr(OPTION,METHOD,VARARGIN) returns a global threshold or level dependent thresholds depending on OPTION. The inputs, VARARGIN, depend on the OPTION and METHOD values.

This file returns the thresholds used throughout the Wavelet Toolbox^™ software for de-noising and compression tools (command line files or GUI tools).

Valid options for the METHOD parameter are listed in the table below.

METHOD
Description

'scarcehi'
See wdcbm or wdcbm2 when used with 'high' predefined value of parameter M.

'scarceme'
See wdcbm or wdcbm2 when used with 'medium' predefined value of parameter M.

'scarcelo'
See wdcbm or wdcbm2 when used with 'low' predefined value of parameter M.

'sqtwolog'
See 'sqtwolog' option in thselect, and see also wden.

'sqtwologuwn'
See 'sqtwolog' option in thselect, and see also wden when used with 'sln' option.

'sqtwologswn'
See 'sqtwolog' option in thselect, and see also wden when used with 'mln' option.

'rigsure'
See 'rigsure' option in thselect, and see also wden.

'heursure'
See 'heursure' option in thselect, and see also wden.

'minimaxi'
See 'minimaxi' option in thselect, and see also wden.

'penalhi'
See wbmpen or wpbmpen when used with 'high' value of parameter ALPHA.

'penalme'
See wbmpen or wpbmpen when used with 'medium' value of parameter ALPHA.

'penallo'
See wbmpen or wpbmpen when used with 'low' value of parameter ALPHA.

'rem_n0'
This option returns a threshold close to 0. A typical THR value is median(abs(coefficients)).

'bal_sn'
This option returns a threshold such that the percentages of retained energy and number of zeros are the same.

'sqrtbal_sn'
This option returns a threshold equal to the square root of the value such that the percentages of retained energy and number of zeros are the same.

`METHOD`	Description
`'scarcehi'`	See `wdcbm` or `wdcbm2` when used with `'high'` predefined value of parameter `M`.
`'scarceme'`	See `wdcbm` or `wdcbm2` when used with `'medium'` predefined value of parameter `M`.
`'scarcelo'`	See `wdcbm` or `wdcbm2` when used with `'low'` predefined value of parameter `M`.
`'sqtwolog'`	See `'sqtwolog'` option in `thselect`, and see also `wden`.
`'sqtwologuwn'`	See '`sqtwolog`' option in `thselect`, and see also `wden` when used with '`sln`' option.
`'sqtwologswn'`	See `'sqtwolog'` option in `thselect`, and see also `wden` when used with `'mln'` option.
`'rigsure'`	See `'rigsure'` option in `thselect`, and see also `wden`.
`'heursure'`	See `'heursure'` option in `thselect`, and see also `wden`.
`'minimaxi'`	See `'minimaxi'` option in `thselect`, and see also `wden`.
`'penalhi'`	See `wbmpen` or `wpbmpen` when used with `'high'` value of parameter `ALPHA`.
`'penalme'`	See `wbmpen` or `wpbmpen` when used with `'medium'` value of parameter `ALPHA`.
`'penallo'`	See `wbmpen` or `wpbmpen` when used with `'low'` value of parameter `ALPHA`.
`'rem_n0'`	This option returns a threshold close to 0. A typical `THR` value is `median(abs(`coefficients`)).`
`'bal_sn'`	This option returns a threshold such that the percentages of retained energy and number of zeros are the same.
`'sqrtbal_sn'`	This option returns a threshold equal to the square root of the value such that the percentages of retained energy and number of zeros are the same.

Discrete Wavelet 1-D Options

Compression using a global threshold.. X is the signal to be compressed and [C,L] is the wavelet decomposition structure of the signal to be compressed.

THR = wthrmngr('dw1dcompGBL','rem_n0',X)
THR = wthrmngr('dw1dcompGBL','bal_sn',X)

Compression using level dependent thresholds.. X is the signal to be compressed and [C,L] is the wavelet decomposition structure of the signal to be compressed.

ALFA is a sparsity parameter (see wdcbm for more information).

THR = wthrmngr('dw1dcompLVL','scarcehi',C,L,ALFA)
      ALFA must be such that 2.5 < ALFA < 10
THR = wthrmngr('dw1dcompLVL','scarceme',C,L,ALFA)
      ALFA must be such that 1.5 < ALFA < 2.5
THR = wthrmngr('dw1dcompLVL','scarcelo',C,L,ALFA)
      ALFA must be such that 1 < ALFA < 2

De-noising using level dependent thresholds.. [C,L] is the wavelet decomposition structure of the signal to be de-noised, SCAL defines the multiplicative threshold rescaling (see wden for more information) and ALFA is a sparsity parameter (see wbmpen for more information).

THR = wthrmngr('dw1ddenoLVL','sqtwolog',C,L,SCAL)
THR = wthrmngr('dw1ddenoLVL','rigrsure',C,L,SCAL)
THR = wthrmngr('dw1ddenoLVL','heursure',C,L,SCAL)
THR = wthrmngr('dw1ddenoLVL','minimaxi',C,L,SCAL)
THR = wthrmngr('dw1ddenoLVL','penalhi',C,L,ALFA)
      ALFA must be such that 2.5 < ALFA < 10
THR = wthrmngr('dw1ddenoLVL','penalme',C,L,ALFA)
      ALFA must be such that 1.5 < ALFA < 2.5
THR = wthrmngr('dw1ddenoLVL','penallo',C,L,ALFA)
      ALFA must be such that 1 < ALFA < 2

Discrete Stationary Wavelet 1-D Options

De-noising using level dependent thresholds.. SWTDEC is the stationary wavelet decomposition structure of the signal to be de-noised, SCAL defines the multiplicative threshold rescaling (see wden for more information) and ALFA is a sparsity parameter (see wbmpen for more information).

THR = wthrmngr('sw1ddenoLVL',METHOD,SWTDEC,SCAL)
THR = wthrmngr('sw1ddenoLVL',METHOD,SWTDEC,ALFA)

The options for METHOD are the same as in the 'dw1ddenoLVL'case.

Discrete Wavelet 2-D Options

Compression using a global threshold.. X is the image to be compressed and [C,S] is the wavelet decomposition structure of the image to be compressed.

THR = wthrmngr('dw2dcompGBL','rem_n0',X)
THR = wthrmngr('dw2dcompGBL','bal_sn',C,S)
THR = wthrmngr('dw2dcompGBL','sqrtbal_sn',C,S)

Compression using level dependent thresholds.. X is the image to be compressed and [C,S] is the wavelet decomposition structure of the image to be compressed. ALFA is a sparsity parameter (see wdcbm2 for more information).

THR = wthrmngr('dw2dcompLVL','scarcehi',C,L,ALFA)
      ALFA must be such that 2.5 < ALFA < 10
THR = wthrmngr('dw2dcompLVL','scarceme',C,L,ALFA)
      ALFA must be such that 1.5 < ALFA < 2.5
THR = wthrmngr('dw2dcompLVL','scarcelo',C,L,ALFA)
      ALFA must be such that 1 < ALFA < 2

De-noising using level dependent thresholds.. [C,S] is the wavelet decomposition structure of the image to be de-noised, SCAL defines the multiplicative threshold rescaling (see wden for more information) and ALFA is a sparsity parameter (see wbmpen for more information).

THR = wthrmngr('dw2ddenoLVL','penalhi',C,S,ALFA)
      ALFA must be such that 2.5 < ALFA < 10
THR = wthrmngr('dw2ddenoLVL','penalme',C,L,ALFA)
      ALFA must be such that 1.5 < ALFA < 2.5
THR = wthrmngr('dw2ddenoLVL','penallo',C,L,ALFA)
      ALFA must be such that 1 < ALFA < 2
THR = wthrmngr('dw2ddenoLVL','sqtwolog',C,S,SCAL)
THR = wthrmngr('dw2ddenoLVL','sqrtbal_sn',C,S)

Discrete Stationary Wavelet 2-D Options

De-noising using level dependent thresholds.. SWTDEC is the stationary wavelet decomposition structure of the image to be de-noised, SCAL defines the multiplicative threshold rescaling (see wden for more information) and ALFA is a sparsity parameter (see wbmpen for more information).

THR = wthrmngr('sw2ddenoLVL',METHOD,SWTDEC,SCAL)
THR = wthrmngr('sw2ddenoLVL',METHOD,SWTDEC,ALFA)

The options for METHOD are the same as in the 'dw2ddenoLVL' case.

Discrete Wavelet Packet 1-D Options

Compression using a global threshold.. X is the signal to be compressed and WPT is the wavelet packet decomposition structure of the signal to be compressed.

THR = wthrmngr('wp1dcompGBL','bal_sn',WPT)
THR = wthrmngr('wp1dcompGBL','rem_n0',X)

De-noising using a global threshold.. WPT is the wavelet packet decomposition structure of the signal to be de-noised.

THR = wthrmngr('wp1ddenoGBL','sqtwologuwn',WPT)
THR = wthrmngr('wp1ddenoGBL','sqtwologswn',WPT)
THR = wthrmngr('wp1ddenoGBL','bal_sn',WPT)
THR = wthrmngr('wp1ddenoGBL','penalhi',WPT)
      see wbmpen with ALFA = 6.25
THR = wthrmngr('wp1ddenoGBL','penalme',WPT)
      see wbmpen with ALFA = 2
THR = wthrmngr('wp1ddenoGBL','penallo',WPT)
      see wbmpen with ALFA = 1.5

Discrete Wavelet Packet 2-D Options

Compression using a global threshold.. X is the image to be compressed and WPT is the wavelet packet decomposition structure of the image to be compressed.

THR = wthrmngr('wp2dcompGBL','bal_sn',WPT)
THR = wthrmngr('wp2dcompGBL','rem_n0',X)
THR = wthrmngr('wp2dcompGBL','sqrtbal_sn',WPT)

De-noising using a global threshold.. WPT is the wavelet packet decomposition structure of the image to be de-noised.

THR = wthrmngr('wp2ddenoGBL','sqtwologuwn',WPT)
THR = wthrmngr('wp2ddenoGBL','sqtwologswn',WPT)
THR = wthrmngr('wp2ddenoGBL','sqrtbal_sn',WPT)
THR = wthrmngr('wp2ddenoGBL','penalhi',WPT)
      see wbmpen with ALFA = 6.25
THR = wthrmngr('wp2ddenoGBL','penalme',WPT)
      see wbmpen with ALFA = 2
THR = wthrmngr('wp2ddenoGBL','penallo',WPT)
      see wbmpen with ALFA = 1.5

Provide feedback about this page

wthresh wtreemgr

Recommended Products

Get MATLAB trial software

Includes the most popular MATLAB recorded presentations with Q&A sessions led by MATLAB experts.

Get the Interactive Kit