feature op• Datenarten: voxel → voxel
• Aufruf: import fullseye as fs; fs.ledger.vol_orientation_coherence(vol, sigma=1.0, rho=3.0) (die Implementierung direkt: import volops; volops.vol_orientation_coherence(vol, sigma=1.0, rho=3.0); aus dem Register: ops3d.get("vol_orientation_coherence"))
Wie stark die lokale Struktur in eine Richtung zeigt (3-D-Strukturtensor).
> Die ausführliche Beschreibung unten ist der Originaltext — Zusammenfassung und Überschriften sind übersetzt.
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].
• Katalog der Beispieldaten (Download-URLs / Lizenzen) — 2-D nutzt skimage.data (BSD/Public Domain) plus synthetische Bilder, 3-D nennt Download-URLs echter Datenquellen (Stanford, PDS, …).
• Herkunft und Literatur der Operatoren — die Quellen der Forschung/Verfahren, auf denen diese Operatorfamilie beruht.
• ct_porosity_and_fibre_morphometry — py -3.11 examples_3d/ct_porosity_and_fibre_morphometry.py
voxel als Eingabe)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. Diese Notiz wird von tools/opdocs.py md erzeugt (nicht von Hand bearbeiten).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.