Wavelet Toolbox

Enhancements

Complex CWT

The cwt function performs continuous wavelet analysis of a real signal using a real or complex wavelet.

Threshold Settings Using the GUI

The threshold lines in the de-noising and compression tools can be dragged using the mouse. The corresponding control buttons (edits, sliders, ...) are automatically updated.

New De-noising and Compression Methods

New methods for de-noising and compression tools using the GUI are available in: Wavelet 1-D, Wavelet 2-D, Wavelet Packet 1-D, and Wavelet Packet 2-D.

Saving De-noising and Compression Parameters

In most of the GUI menus, Save options are available. When signals, coefficients or decompositions are obtained using de-noising or compression, the related parameters (wavelet name and thresholds) are now saved when the save operation is performed.

Length or Size Information

In almost all the GUI windows, a frame containing the analysis parameters displays in the upper right corner. In addition to the signal or image name, the length of the signal or the size of the image now displays.

Menus and Toolbar

The MATLAB default toolbar and menus displayed in figures are now available in almost all the GUI windows updated with the specific wavelet-oriented features.

Extension Mode for DWT

1. New extension modes
   
   

   Command to set the mode	Description
   dwtmode('sym')	Sets the DWT mode to symmetrization (new default mode, boundary value replication)
   dwtmode('zpd')	Sets the DWT mode to zero padding
   dwtmode('spd') or dwtmode('sp1')	Sets the DWT mode to smooth padding of order 1 (first derivative interpolation at the edges)
   dwtmode('sp0')	Sets the DWT mode to smooth padding of order 0 (constant extension at the edges)
   dwtmode('ppd')	Sets the DWT mode to periodic padding (periodic extension at the edges)

The five modes above are applicable for both 1-D and 2-D extensions. The associated DWT is slightly redundant for an arbitrary length signal. The following mode sets the DWT to periodization:

     dwtmode('per')

This option produces the smallest wavelet decomposition. All functions that use the DWT (i.e., Discrete Wavelet (1-D & 2-D) or Wavelet Packet (1-D & 2-D)) use the specified DWT extension mode.

2. Changing the default extension mode

The default extension mode is 'sym' (boundary value replication). This default can be changed. The default mode is loaded from the file DWTMODE.DEF if it exists.

If not, the file DWTMODE.CFG (in the toolbox/wavelet/wavelet directory) is used.

dwtmode('save',mode) saves mode as the new default mode in the file DWTMODE.DEF (all the files named DWTMODE.DEF are deleted before saving).

dwtmode('save') is equivalent to dwtmode('save',currentMode).

New Functions

Compatibility with Earlier Versions