Module: Extrema

Description:

Extracts either local or regional extrema from an image, which are either minima or maxima. A set of points is an maximum if all pixels in its neighbourhood have a lower intensity.

Selection of the maxima. (a) is the original image, (b) is the local maxima, and (c) is regional maxima (both using 18-connectivity).

Connections:

Image

[required]
The input image comes in through this port. For now, the only input type that has been implemented is HxUniformScalarField3.

Ports:

Extrema

Specifies which extrema to look for.

Connectivity

Specifies the neighbourhood for extremum checking.

Illustration of the different connectivities. (a): 6-, (b): 18-, and (c): 26-connectivity (in case you didn't figure it out, n-connectivity means n pixels in the neighbourhood).

Options

Option to extract extrema and filter them according to their influence zones.

Filter

Only select extrema by different characteristics of its influence zones: height (greylevel difference between top and bottom), area (number of pixels in the zone), and volume (hypervolume of the zone).

Height

Height threshold of the influence zone.

Area

Area threshold of the influence zone.

Volume

Volume threshold of the influence zone.

Action button

Push this button to start the computation.

Commands:

Additional options can be accessed when typing in the console Extrema COMMAND_NAME. Typing the command again usually reverts back to original settings.

`verbose`

Displays timing information after the computation. Retype to hide info.

`create`

Runs the computation. Returns the name of the output, so it can be used in a script, such as set RESULT [Extrema create].