vol_orientation_coherence — 3D feature op

数据种类:voxelvoxel

调用: import fullseye as fs; fs.ledger.vol_orientation_coherence(vol, sigma=1.0, rho=3.0)(要直接调用实现,import volops; volops.vol_orientation_coherence(vol, sigma=1.0, rho=3.0);从台账取用则 ops3d.get("vol_orientation_coherence"))

用法

局部结构在多大程度上指向同一方向(3-D 结构张量)。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

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]`.

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

可运行的示例(实际调用该算子并已验证的样例)

ct_porosity_and_fibre_morphometrypy -3.11 examples_3d/ct_porosity_and_fibre_morphometry.py

类型可衔接的下一个算子(可接受 voxel 作为输入)

voxel_to_mips · voxel_to_mesh · signed_distance_field · to_points · sobel3d · hessian3d · curvature_maps · edt_jfa

同类别(feature)

sobel3d · hessian3d · curvature_maps · edt_jfa · vol_frangi · vol_local_std · vol_local_thickness · vol_euler_number


*Provenance: volops.py — 3D 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.