Wavelet Toolbox

Saving Information to Disk

Using specific file formats, the graphical tools let you save synthesized signals or images, as well as one- or two-dimensional wavelet packet decomposition structures. This feature provides flexibility and allows you to combine command line and graphical interface operations.

Saving Synthesized Signals

You can process a signal in the Wavelet Packet 1-D tool, and then save the processed signal to a MAT-file.

For example, load the demo analysis:

FileDemo Analysisdb1 - depth: 2 - ent: shannon --> sumsin

and perform a compression or de-noising operation on the original signal. When you close the Wavelet Packet 1-D De-noising or Wavelet Packet 1-D Compression window, update the synthesized signal by clicking Yes in the dialog box.

Then, from the Wavelet Packet 1-D tool, select the FileSave Synthesized Signal menu option.

A dialog box appears allowing you to select a directory and filename for the MAT-file. For this example, choose the name synthsig.

To load the signal into your workspace, simply type:

load synthsig
whos

Name	Size	Bytes	Class
synthsig	1x1000	8000	double array
valTHR	1x1	8	double array
wname	1x3	6	char array

The synthesized signal is given by synthsig. In addition, the parameters of the de-noising or compression process are given by the wavelet name (wname) and the global threshold (valTHR).

valTHR

valTHR =
    1.9961

Saving Synthesized Images

You can process an image in the Wavelet Packet 2-D tool, and then save the processed image to a MAT-file (with extension mat or other).

For example, load the demo analysis:

FileDemo Analysisdb1 - depth: 1 - ent: shannon --> woman

and perform a compression on the original image. When you close the Wavelet Packet 2-D Compression window, update the synthesized image by clicking Yes in the dialog box that appears.

Then, from the Wavelet 2-D tool, select the FileSave Synthesized Image menu option.

A dialog box appears allowing you to select a directory and filename for the MAT-file. For this example, choose the name wpsymage.

To load the image into your workspace, simply type:

load wpsymage
whos

Name	Size	Bytes	Class
X	256x256	524288	double array
map	255x3	6120	double array
valTHR	1x1	8	double array
wname	1x3	6	char array

The synthesized image is given by X. The variable map contains the associated colormap. In addition, the parameters of the de-noising or compression process are given by the wavelet name (wname) and the global threshold (valTHR).

Saving One-Dimensional Decomposition Structures

The Wavelet Packet 1-D tool lets you save an entire wavelet packet decomposition tree and related data to your disk. The toolbox creates a MAT-file in the current directory with a name you choose, followed by the extension wp1 (wavelet packet 1-D).

Open the Wavelet Packet 1-D tool and load the demo analysis:

FileDemo Analysisdb1 - depth: 2 - ent: shannon --> sumsin

To save the data from this analysis, use the menu option FileSave Decomposition.

A dialog box appears that lets you specify a directory and file name for storing the decomposition data. Type the name wpdecex1d.

After saving the decomposition data to the file wpdecex1d.wp1, load the variables into your workspace.

load wpdecex1d.wp1 -mat
whos 

Name	Size	Bytes	Class
data_name	1x6	12	char array
tree_struct	1x1	11176	wptree object
valTHR	0x0	0	double array

The variable tree_struct contains the wavelet packet tree structure. The variable data_name contains the data name and valTHR contains the global threshold, which is currently empty since the synthesized signal does not exist.

Saving Two-Dimensional Decomposition Structures

The file format, variables, and conventions are exactly the same as in the one-dimensional case except for the extension, which is wp2 (wavelet packet 2-D). The variables saved are the same as with the one-dimensional case, with the addition of the colormap matrix map:

Name	Size	Bytes	Class
data_name	1x5	10	char array
map	255x3	6120	double array
tree_struct	1x1	527400	wptree object
valTHR	1x1	8	double array

Save options are also available when performing de-noising or compression inside the Wavelet Packet 1-D and Wavelet Packet 2-D tools.

In the Wavelet Packet De-noising windows, you can save the de-noised signal or image and the decomposition. The same holds true for the Wavelet Packet Compression windows.

This way, you can save directly many different trials from inside the De-noising and Compression windows without going back to the main Wavelet Packet windows during a fine-tuning process.

Note    When saving a synthesized signal (1-D), a synthesized image (2-D) or a decomposition to a MAT-file, the extension of this file is free. The mat extension is not necessary.

Importing and Exporting from Graphical Tools

Loading Information into the Graphical Tools