feature op• Data kinds: voxel → voxel
• Call: import fullseye as fs; fs.ledger.vol_frangi(vol, scales=(1, 2, 3), alpha=0.5, beta=0.5, c=None, black_ridges=False) (implementation को सीधे call करना हो तो import volops; volops.vol_frangi(vol, scales=(1, 2, 3), alpha=0.5, beta=0.5, c=None, black_ridges=False), registry से लेना हो तो ops3d.get("vol_frangi"))
3-D Frangi vesselness — multiscale tubular-structure enhancement।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
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.
• 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।
• vessel_metrology — py -3.11 examples_3d/vessel_metrology.py
• volume_downsampling — py -3.11 examples_3d/volume_downsampling.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_local_std · vol_local_thickness · 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.