feature opvoxel → voxelimport fullseye as fs; fs.ledger.vol_frangi(vol, scales=(1, 2, 3), alpha=0.5, beta=0.5, c=None, black_ridges=False) (実装を直接呼ぶなら import volops; volops.vol_frangi(vol, scales=(1, 2, 3), alpha=0.5, beta=0.5, c=None, black_ridges=False)、台帳から引くなら ops3d.get("vol_frangi"))3-D Frangi vesselness — multiscale tubular-structure enhancement.
For every sigma in scales the gamma-normalised Hessian is formed, its
three eigenvalues |l1| <= |l2| <= |l3| are taken, and the Frangi response
V = (1 - exp(-Ra**2 / 2 alpha**2)) * exp(-Rb**2 / 2 beta**2)
* (1 - exp(-S**2 / 2 c**2))
is evaluated, where Ra = |l2|/|l3| (plate vs. line), Rb = |l1|/sqrt|l2 l3|
(blob deviation) and S = sqrt(l1**2 + l2**2 + l3**2) (structure strength).
The response is set to 0 where the contrast polarity is wrong (bright tube:
l2 > 0 or l3 > 0; black_ridges=True flips this). The maximum over
scales is taken and the volume is normalised to [0, 1].
scales : sequence of float — Gaussian sigmas, in voxels, to bracket the
vessel radii of interest (see the module “scale-dependent” limitation).
alpha, beta : sensitivities of the plate- and blob-suppression terms (Frangi’s
defaults 0.5).
c : half the maximum Hessian norm S at each scale when None (Frangi’s
adaptive suggestion); otherwise a fixed structure-strength scale.
black_ridges : False (default) enhances bright tubes on a dark
background; True enhances dark tubes on a bright background.
Returns a (D, H, W) float64 volume in [0, 1]. Reference: Frangi et al.,
MICCAI 1998.
py -3.11 examples_3d/vessel_metrology.pypy -3.11 examples_3d/volume_downsampling.pyvoxel を入力に取れる)voxel_to_mips · voxel_to_mesh · signed_distance_field · to_points · sobel3d · hessian3d · curvature_maps · edt_jfa
feature)sobel3d · hessian3d · curvature_maps · edt_jfa · vol_sato · vol_hessian_blobness · vol_gradient_magnitude · vol_local_maxima
Provenance: volops.py — 3D operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.