feature op• Data kinds: voxel → voxel
• Call: import fullseye as fs; fs.ledger.vol_orientation_coherence(vol, sigma=1.0, rho=3.0) (implementation को सीधे call करना हो तो import volops; volops.vol_orientation_coherence(vol, sigma=1.0, rho=3.0), registry से लेना हो तो ops3d.get("vol_orientation_coherence"))
local structure कितनी मज़बूती से एक ही दिशा में है (3-D structure tensor)।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
Builds J = G_rho * (grad I)(grad I)^T and returns
(l1 - l3) / (l1 + l2 + l3), l1 >= l2 >= l3
in [0, 1]: 1 where one direction dominates (a fibre, a lamella edge, a crack face), 0 where the gradient is isotropic (a uniform block, white noise) or where two directions are equally strong. *sigma* smooths before differentiating (so noise is not differentiated into structure); *rho* is the integration width — make it larger than the spacing of the structure you are measuring.
HALCON computes this tensor and throws it away: coherence_enhancing_diff uses it to steer a diffusion but exposes neither the orientation nor the coherence. Returning the measurement is the point of this operator.
Applicability. (1) rho too small collapses the tensor to rank 1 and the answer sticks at 1 everywhere — that is *not* perfect alignment, it is a failure to measure. (2) Two fibre families crossing at equal strength read as 0, indistinguishable from a uniform block; pair it with vol_local_std to tell "no direction" from "no structure". (3) Voxels whose tensor trace is below 1e-6 of the volume maximum return 0.
Returns a (D, H, W) float64 volume in [0, 1].
• 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_local_thickness
*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.