occlusion_edges — 3D `range_image` op

• Data kinds: depth → image2d

• Call: import fullseye as fs; fs.ledger.occlusion_edges(depth, rel_thresh=0.05) (to call the implementation directly, import range_image; range_image.occlusion_edges(depth, rel_thresh=0.05); from the registry, ops3d.get("occlusion_edges"))

Usage

Detect depth discontinuities (the foreground/background boundary = occlusion edges). → bool HxW.

An occlusion edge is a discontinuity (step) in depth, not a slope. A uniformly sloped surface is continuous and contains no occlusion, so it must not be flagged. The first-order gradient (= depth/pixel) is the slope itself and cannot distinguish a step from a slope (and comparing it with a fraction of the absolute depth is dimensionally inconsistent).

So the per-axis second-order difference (equivalent to a discrete Laplacian) d[i+1]-2*d[i]+d[i-1] is used. On a uniform slope (depth linear in the neighbourhood) the second difference ≈ 0; at a fronto-parallel step it is large on both sides. Pixels where this relative depth jump, normalised by the local depth, exceeds rel_thresh are taken as boundaries.

Background guides (the physics and conventions behind this op)

• blender_interop — Using Blender alongside — build the shape, measure it with fullseye (pitfalls: axes, units, ground truth)

• depth_sensors — Depth sensors — ranging principles, real-device figures, how dropouts appear

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.

Runnable examples (verified samples that actually call this op)

• range_image — py -3.11 examples_3d/range_image.py

Ops the type connects to (they accept `image2d` as input)

fuse_to_voxel · fit_poly_surface · eval_poly_surface · surface_form_error · background_flatten · polar_unwrap · fit_zernike · matcap_shade

Same category (`range_image`)

depth_to_organized_points · normals_from_depth · bearing_angle_image

*Provenance: range_image.py — 3D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

occlusion_edges — 3D range_image op