Building Complex Restoration Filters

To build a complex multi-component restoration filter, open the Filter builder dialog available from the Restore menu. The tools that can be used as building blocks are listed on the left side of the dialog. To incorporate a tool in a structure shown in the middle of the panel, highlight the corresponding item and click on the INSERT button (situated on the right side above the tool list). Moving the cursor along the structure select the appropriate insertion point (insertion points turn green when active) and "drop" the tool by clicking the left mouse button. When you start building a complex filter from the scratch there is only one insertion point you can use, placed before two triangles representing the input file and the output file.

If, after pressing the INSERT button, you decide to change the selected tool to another one click the NORMAL button (situated on the left side above the tool list) and repeat the insertion procedure.

Finally, to remove a tool from an existing structure click on it using the right mouse button and choose the Remove command from the pop-up menu that will appear on the screen.

Repeat the procedure summarized above until all building blocks you wish to incorporate in your filter are inserted.

For your convenience all building blocks comprising a complex structure are numbered. If you add or remove a block in the middle of the structure the numbering may change. Each block has an activity checkbox on its right hand side. You can use it to temporarily disable selected functions - when the box remains unchecked the corresponding item is bypassed during processing. Bypassing is very useful when it comes to testing multi-component filters as it helps one to isolate effects (whether positive or negative) introduced by a particular element of a complex structure.

When the filter is ready, use the Info window to describe its features and the Rename button to change its name. To remove a filter that is not needed any more, pick it from the list and click the Remove button.

Several useful, ready-to-use structures are provided along with DART XP Pro, namely : declicking combined with dehissing, declicking combined with denoising, two-stage declicking, reverse-time declicking, reverse-time declicking combined with dehissing and reverse-time declicking combined with denoising.

The existing filter structures can be utilized in two different ways.

First, you can insert the entire structure anywhere in the already built filter (at the beginning, middle or end). To do this press the Insert MyFilter button placed below the list of available tools and use the Filter browser dialog, that will appear on the screen to select structure you wish to include. After closing the Filter browser dialog, choose the insertion point and drop the structure.

Second, you can use an existing structure as a starting point for building a new one. If you don't want to save the original filter, simply choose (or reuse) its name from the MyFilter list and introduce the changes. If you want to create a new filter without altering the original one press the Save as button to save a selected structure under a new name prior to modification.

Binary (detection) files

If the multi-component restoration filter contains at least one declicking unit, DART XP Pro will create a detection file with information about the introduced changes (detection alarms). If several declickers are combined in one structure, the binary detection signals obtained at different stages of processing are "added" - the detection bit is set to 1 if the corresponding sample was scheduled for reconstruction by any of the outlier detectors. If the stereo to mono conversion is performed after declicking, the binary signals obtained for the left and right channel are also added - unless only one channel is selected. If conversion takes place in the opposite direction (mono to stereo) the corresponding binary signals are duplicated.

NOTICE

No detection file will be created if the sample rate conversion is performed after or prior to declicking.