Recherche Google
IntroductionSignal Manipulation > Surface Filters > Surface Filter Tools
page précédentepage suivante

Surface Filter Tools

AS offers a panel of area filter tools that are used to delineate or draw various type of items in a sonogram.

Tools Palette


The selection tools are accessed with a click on the second item of the palette located at the top of the AS window.

Tool Types
  • Surface : draw rectangular surfaces with a click and drag

  • Region : draw free polygons with successive clicks, or with a click and drag

  • Pencil : draw free lines of various thickness, for the selection of partials for instance, or any other type of item.

  • Harmonic pencil : the pencil stroke is copied and translated with a constant harmonic relationship.


The surface tool is selected by default. Select an item in the menu with a click. The selected tool will be displayed in the palette.

Each tool can also be selected pressing a specific key.

Automatic Selection Tools Conversion

Clicking with any of the surface tools in the global waveform window converts it into the player on the fly, represented by a loudspeaker.

Selection tools are automatically converted into a standard pointer when browsing the processing sequencer.

Playing a Sound on the Fly


Pencil Stroke Size

The lower part of the menu allows to define both pencil strokes size. Click on the area tool icon and select the Pencil Size menu item.

Harmonic Pencil Settings

A number of parameters can be set via the menu. Click on the area tool icon and select the Harmonic Pencil Settings menu item.

  • Pencil Gain : filter gain, which can be subsequently modified

  • Pencil Stroke Size in pixels : this graphic parameter has an influence upon the frequential precision of the selection.

  • Bandwidth Compensation : when a pencil stroke is done, its thickness in pixels results into a given bandwidth. This bandwidth is then translated to the superior harmonics according to their rank, and to a compensation factor. For instance, with a 100 % compensation, if a stroke for the F0 covers a range from 100 to 110 Hz, the thickness of the upper harmonics will be increased on either sides of a central frequency, in order to covers 20, 30, 40 Hz bandwidth, from 200 to 220 Hz, 300 to 330 Hz, 400 to 440 Hz, and so on. With a 10% compensation, ranges will be restricted to 2, 3, 4 Hz...

  • Number of Harmonics : the global number of harmonics to be represented, be they odd or even or both.

  • Harmonics Parity : odd harmonics are the produce of the F0 by an odd integer, even harmonics by an even integer

  • Harmonic Number : pencil stroke's harmonic rank. The full series is always represented, so that harmonics of inferior rank are automatically added by AS.

  • Harmonics List : harmonics respective rank in a list with commas and parenthesis, such as (1, 3, 4, 5, 8). The choice of this option prevails over the preceeding ones.

Pencil Strokes Posterior Modifications

Any modification via the harmonic pencil's settings will affect the basic pencil size.

Posterior Modifications of Pencil Strokes
page précédentepage suivante
A propos...IRCAMRéalisé avec Scenari