feature op• Data kinds: voxel → voxel
• Call: import fullseye as fs; fs.ledger.vol_local_thickness(vol_binary, spacing=None, max_radius=None) (implementation को सीधे call करना हो तो import volops; volops.vol_local_thickness(vol_binary, spacing=None, max_radius=None), registry से लेना हो तो ops3d.get("vol_local_thickness"))
Local thickness map: हर voxel को ढकने वाली सबसे बड़ी ball का diameter।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
For every foreground voxel this is max{ 2r : the voxel lies inside some ball of radius r that fits entirely in the foreground } — the classical granulometric size, and the quantity trabecular-bone and industrial-CT work calls *local thickness* (a pore's local thickness is its diameter; a wall's is its thickness). Computed from the exact distance transform: take the voxels whose distance is at least r as ball centres and paint the balls they cover, largest radius first.
★Distinct from vol_wall_thickness, which walks a single probe segment p0 -> p1 and returns a list of crossings. This one is a *volume*, so the thickness of every feature is available at once and can be histogrammed.
Pass *spacing* (sz, sy, sx) (or a volio.VolumeMeta) and the result is in millimetres; otherwise in voxels. *max_radius* caps the search (in the same units); leave it None to derive it from the largest distance actually present, which costs one pass more but never saturates.
Applicability. (1) The foreground comes from a single threshold, so beam hardening or a brightness gradient biases the thickness across the volume — flatten first. (2) With anisotropic voxels the ball is a ball in millimetres, not in voxels, so *spacing* is not cosmetic. (3) A feature three voxels across is quantised at better than 30% only if you say so:
report the voxel size next to any thickness number.
Returns a (D, H, W) float64 volume, 0 on the background.
• Sample data catalog (DL URL / license) — 2-D के लिए skimage.data (BSD/public) + synthetic, 3-D के लिए real data sources (Stanford/PDS आदि) के DL URL।
• Operators का स्रोत और संदर्भ — इस op family के मूल research/methods के स्रोत।
• ct_porosity_and_fibre_morphometry — py -3.11 examples_3d/ct_porosity_and_fibre_morphometry.py
voxel को input के रूप में लेते हैं)voxel_to_mips · voxel_to_mesh · signed_distance_field · to_points · sobel3d · hessian3d · curvature_maps · edt_jfa
feature)sobel3d · hessian3d · curvature_maps · edt_jfa · edt_jfa_vector · vol_frangi · vol_local_std · vol_orientation_coherence
*Provenance: volops.py — 3D operator registry. यह per-op note tools/opdocs.py md से अपने-आप generate होता है (हाथ से edit न करें)।*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.