boundary op• Data kinds: voxel → points
• Call: import fullseye as fs; fs.ledger.vol_boundary_points(vol_binary, spacing=None, connectivity=6, origin=(0, 0, 0)) (to call the implementation directly, import volops; volops.vol_boundary_points(vol_binary, spacing=None, connectivity=6, origin=(0, 0, 0)); from the registry, ops3d.get("vol_boundary_points"))
Boundary shell as an (N, 3) point cloud in (z, y, x) order.
The bridge from the voxel world to the point-cloud world at minimal memory:
only the *surface* voxels of the mask become points (inner boundary, see vol_boundary), so a solid object of a million voxels typically yields a few tens of thousands of points — ready for fit_sphere3 / smallest_box3 / register_fpfh and friends without ever materialising the full grid as points.
Coordinates are (index + origin) * spacing per axis: pass *spacing* (sz, sy, sx) (or a volio.VolumeMeta) for physical millimetre coordinates, and pass the offset returned by vol_crop_domain as *origin* so points from a cropped volume land in the uncropped frame (*origin* is in voxel units — it is added to the index *before* the spacing multiply; it must be finite, and may be fractional for a subvoxel shift). An empty mask returns an empty (0, 3) array (a valid question with a valid empty answer — unlike a crop, which needs a box to exist).
Returns an (N, 3) float64 array, rows ordered z-major (deterministic).
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• roi_domain_boundary — py -3.11 examples_3d/roi_domain_boundary.py
points as input)points_to_voxel · gaussians_to_voxel · estimate_point_normals · to_points · match_points_ncc · match_pca · moment_axes · icp_point2point_3d
boundary)*Provenance: volops.py — 3D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.