Refining Regions of Interest
A number of options, described below, are available for refining regions of interest.
In cases in which you need to refine threshold segmentation results or need to isolate objects of a certain size, you can remove small objects from a region of interest, as well as isolate larger objects. These operations can be based on voxel counts or by rank.
Right-click a region of interest in the Data Properties and Settings panel and then choose Process Islands in the pop-up menu. You can then choose to remove or keep objects as described in the following table.
| Description | |
|---|---|
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Removes all discrete objects, as determined by the
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Keeps all objects, as determined by the
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nth First Biggest |
Removes a selected number of the largest connected components, as determined by the
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nth First Biggest |
Keeps a selected number of the largest connected components, as determined by the
|
* Objects with an identical voxel count will be considered as unique objects when ranked.
Lets you fill connected pores with an opening diameter smaller than the selected threshold. You should note connected pores are defined as segments that are connected to the borders of its volume. Holes and other enclosed segments are classified as non-connected and will not be filled.
The opening diameter of the connected pores that you want to fill is selectable in the Threshold dialog, shown below. The output of this process is a new region of interest.
Threshold dialog
Automatically removes objects, which can be defined as groups of labeled voxels that are connected, within the current region of interest that intersect with a selected ROI or multi-ROI.
In the example below, the objects in the ROI with the orange circles that were touching the blue ROI were removed.
- Right-click the region of interest you need to modify and then choose Refine Region of Interest > Remove Objects That Touch Another ROI or Multi-ROI in the pop-up menu.
- Choose the ROI or multi-ROI that is touching parts of the region of interest that you are modifying in the Choose ROI or Multi-ROI dialog.

- Click OK.
Touching objects are removed automatically from the selected ROI.
Creates a new region of interest that contains only labeled voxels with an original neighbor count greater than or equal to a selected threshold. Thresholds are selectable in the Neighbor Count dialog, shown below.
This option is often used in the topological analysis of skeletons.




