Author Topic: New Bug Discovered  (Read 3412 times)

Offline Juan Conejero

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New Bug Discovered
« on: 2005 May 04 02:43:03 »
Hi all,

Nicolas Boussion has found a new bug on the À Trous Wavelets window.

This just-discovered bug does not affect the ATrousWaveletTransform process itself, which is, as far as we know, bug-free.

The error that Nicolas has found is just a mistake in the "5x5 Linear Interpolation" scaling function filter values. The correct function is:

0.0156  0.0312  0.0625  0.0312  0.0156
0.0312  0.0625  0.1250  0.0625  0.0312
0.0625  0.1250  0.2500  0.1250  0.0625
0.0312  0.0625  0.1250  0.0625  0.0312
0.0156  0.0312  0.0625  0.0312  0.0156


but the PixInsight LE application initializes it automatically as:

0.0156  0.0312  0.0625  0.0312  0.0156
0.0312  0.0625  0.1250  0.0625  0.0312
0.0625  0.1250  0.2500  0.1250  0.0625
0.0312  0.0625
 0.0625  0.0625  0.0312
0.0156  0.0312  0.0625  0.0312  0.0156


In red color I have marked the wrong filter element.

It is amazing how this error has gone unnoticed until now. My eyes must have looked at these numbers one hundred times...

If you use the 5x5 Linear Interpolation scaling function, the workaround is as follows:

    1. On the À Trous Wavelets window, select the Scaling Function tabsheet.

    2. Select the 5x5 Linear Interpolation function from the filter selection combo box.

    3. Manually correct the filter. Look at the filter values shown above, and locate the red-marked element. Type 0.125 to replace the 0.0625 wrong value.

    4. Click the Manage button.

    5. On the Manage Filters dialog box, edit a new name for the filter. For example, a good choice might be "5x5 Linear Interpolation (Corrected)".

    6. Ensure that the "Make changes permanent" check box is checked (it's checked by default).

    7. The Add radio button should be checked, and you shouldn't be allowed to uncheck it. If this is not this way, then you selected the wrong filter on the Scaling Function tab sheet.

    8. Click Ok.[/list]

    From now on, the corrected filter will be available on the Scaling Function tab sheet. The wrong filter will also be available, since it is automatically defined by the PixInsight LE application, so you'll have to select te good one manually. Sorry for the inconvenience.

    Merci beaucoup to Nicolas Boussion for this bug discovery.

    Regards,

    Juan
    Juan Conejero
    PixInsight Development Team
    http://pixinsight.com/