grid_hole_points — DRIVE braidpath op

• Data kinds: image2d → matrix

• Call: import fullseye as fs; fs.ledger.grid_hole_points(grid) -> 'np.ndarray' (to call the implementation directly, import braidpath; braidpath.grid_hole_points(grid) -> 'np.ndarray'; from the registry, opsdrive.get("grid_hole_points"))

• GPU: none (CPU reference implementation only)

Usage

One representative point per grid hole (connected component of blocked cells not touching the border): the centre [x, y] of the blocked cell nearest the centroid.

Blocked regions touching the border are connected to the outside world and are not holes (they add no path classes). 4-connectivity (same as movement).

Raises: ValueError (the grid is empty, not 2-D, or contains non-finite values —— NaN is not read as “traversable”).

References (sample data, literature)

• 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.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_braid_homotopy_classes — py -3.11 examples/poc_braid_homotopy_classes.py

Ops the type connects to (they accept matrix as input)

world_camera · lidar_scan · relative_motion · foe_from_motion · flow_from_depth_motion · ttc_truth · world_materials · mesh_signed_volume

Same category (braidpath)

braid_from_trajectories · braid_reduce · braid_artin_images · dynnikov_coordinates · dynnikov_act · braid_equivalent · homotopy_class_compare · pairwise_winding


*Provenance: braidpath.py — DRIVE 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.