Image processing tools are plug-ins which take one or several images as input, and return a result image. The tools can be interactively called on individual images, or they can be used as stages in a processing pipeline.
Tools Selection
The processing tools can be called interactively using the 
button in the image sidebar.
As a result, the list of available tools appears
from which a tool can be selected.
Alternatively, the list can be obtained as illustrated below by the Ext tab in the tools section and activating the selection arrow.
Tool Operation
After selecting a tool from the list (and activating Run in the tool version), a specific dialog window is opened with a short explanation and the parameters needed for processing. Shown below is the Filter dialog window as an example.
The buttons at the bottom are common to all tools. If the Replace box is checked, the current images are overwritten by the results. Otherwise, a new image series is created for returning the results and added to the series list. ? provides help information of the tool functionality. Ok start the actual data processing.
The functionality of the external tools is described below, except for the Partial Volume Correction (PVC) tools which are explained separately.