vol_local_thickness — 3D feature op

• 数据种类:voxel → voxel

• 调用: import fullseye as fs; fs.ledger.vol_local_thickness(vol_binary, spacing=None, max_radius=None)(要直接调用实现,import volops; volops.vol_local_thickness(vol_binary, spacing=None, max_radius=None);从台账取用则 ops3d.get("vol_local_thickness"))

用法

局部厚度图 —— 能覆盖每个体素的最大球的直径。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

For every foreground voxel this is ``max{ 2r : the voxel lies inside some ball

of radius r that fits entirely in the foreground }`` — the classical

granulometric size, and the quantity trabecular-bone and industrial-CT work

calls *local thickness* (a pore's local thickness is its diameter; a wall's is

its thickness). Computed from the exact distance transform: take the voxels

whose distance is at least `r` as ball centres and paint the balls they

cover, largest radius first.

★**Distinct from `vol_wall_thickness`**, which walks a single probe segment

`p0 -> p1` and returns a list of crossings. This one is a *volume*, so the

thickness of every feature is available at once and can be histogrammed.

Pass *spacing* `(sz, sy, sx) (or a :class:volio.VolumeMeta`) and the

result is in millimetres; otherwise in voxels. *max_radius* caps the

search (in the same units); leave it `None` to derive it from the largest

distance actually present, which costs one pass more but never saturates.

Applicability. (1) The foreground comes from a single threshold, so

beam hardening or a brightness gradient biases the thickness across the

volume — flatten first. (2) With anisotropic voxels the ball is a ball in

millimetres, not in voxels, so *spacing* is not cosmetic. (3) A feature

three voxels across is quantised at better than 30% only if you say so:

report the voxel size next to any thickness number.

Returns a `(D, H, W)` float64 volume, 0 on the background.

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_morphometry — py -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_orientation_coherence · 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.