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Geometric shape primitives

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Compound ROIs

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Regions in arbitrary dimensionsΒΆ

While it is possible to use geometric shapes to specify regions in physical dimensions, this does not translate meaningfully to arbitrary dimensions. The following primitives work in any “dimension” with a discrete or continuous range by permitting the selection of specific values, or sub-ranges.

These “nD” shapes (Value, Values, Range) and the extrusion and combining shapes (Extrude, Combine), permit the specification of ROIs in multiple arbitrary dimensions, and their combination with geometry in 1D, 2D and 3D.

Just as all 1D, 2D and 3D geometry can be converted to the respective 1D, 2D or 3D bitmask or greymask representing the described shape, all nD primitives in higher dimensions can be converted to 1D bitmask or greymask. A 1D bitmask for each dimension will allow efficient iteration over the higher-order dimensions using the resulting bitmaps.

By default, a ROI is unconstrained within all dimensions. The addition of constraints restricts it to particular dimensions, or subsets thereof.


RL. Should we be unconstrained by default, or completely constrained? Should this behaviour be different for “real” dimensions (xyzt) compared with virtual dimensions such as channels?

Should we constrain the ROI to a single timepoint when tracking?

Should x/y/z be blocked for nD operations? I.e. don’t allow the nD shapes to specify regions in 3D space, and restrict them to non-physical dimensions.