Sphere Specification

Layer Specification

Sphere annotations are stored on a napari Points layer and can contain multiple splines.

• Points.data is an (n, d) array of n d-dimensional points.
• Points.features is a table which will contain column called
  • sphere_id, an integer id for each sphere.
  • radius, a radius for each sphere.
• Points.metadata["n3d_metadata"] is a dictionary with the following key/value pairs
• annotation_type: sphere

Zarr Array Specification

The following assumes an n3d file has been read into a variable called n3d using the zarr library

import zarr

zarr.load('sphere.n3d')

• n3d is an (n, d) zarr.core.Array containing the center of each sphere
• n3d.attrs["annotation_type"] is "sphere"
• n3d.attrs["sphere_id"] is an (n, ) array containing a unique id for each sphere
• n3d.attrs["radius"] is an (n, ) array containing the radius for each sphere