Generating Convex Hulls
Dragonfly lets you generate convex hulls as filled or outlined regions of interest or multi-ROIs, or as meshes. Convex hulls are calculated from the minimum set of points that define a polygon containing all of the labeled voxels of a region of interest or all of the labeled voxels of each connected component in a multi-ROI. If you imagine the points as pegs on a board, you can find the convex hull by surrounding the pegs by a loop of string and then tightening the string until there is no more slack. In the illustration below, a convex hull as a mesh (in blue) was generated from a region of interest describing the outline of a mechanical part.
Convex hull as a mesh
Generating Convex Hulls from ROIs
The options for generating convex hulls from ROIs include the following:
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Description |
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A Filled ROI |
Generates a convex hull as a new region of interest that is filled. |
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An Outer Shell ROI |
Generates a convex hull as a new region of interest that is outlined. |
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A Mesh |
Generates a convex hull as a mesh. |
How to Generate a Convex Hull from an ROI
- Right-click the required ROI in the Data Properties and Settings panel.
- Choose the type of convex hull you want to generate in the pop-up menu.
The Binning dialog appears.
- Select a Binning factor within the range of 1 to 8, as required.
Note Binning is the downsampling factor used when generating the space where the convex hull is created prior to its re-projection in the initial space.
- Click OK to generate the convex hull.
Generating Convex Hulls from Multi-ROIs
The options for generating convex hulls from multi-ROIs include the following:
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Description |
|---|---|
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A Multi-ROI, Each Label Being Filled |
Generates a new multi-ROI in which each label of the multi-ROI is a filled convex hull. |
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A Multi-ROI, Each Label as an Outer Shell |
Generates a new multi-ROI in which each label of the multi-ROI is an outlined convex hull. |
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A Mesh for Each Multi-ROI Label |
Generates a series of meshes as convex hulls, one for each label of the multi-ROI. |
How to Generate a Convex Hull from a Multi-ROI
- Right-click the required multi-ROI in the Data Properties and Settings panel.
- Choose the type of convex hull you want to generate in the pop-up menu.
The Binning dialog appears.
- Select a Binning factor within the range of 1 to 8, as required.
Note Binning is the downsampling factor used when generating the space where the convex hull is created prior to its re-projection in the initial space.
- Click OK to generate the convex hull(s).
