feature op• 数据种类:voxel → measurement
• 调用: import fullseye as fs; fs.ledger.vol_euler_number(vol_binary, connectivity=26)(要直接调用实现,import volops; volops.vol_euler_number(vol_binary, connectivity=26);从台账取用则 ops3d.get("vol_euler_number"))
• 经台账调用的返回值: fullseye.ledger.vol_euler_number(...) 只返回**声明的 out 类型 measurement 的值**(底层函数还会返回辅助信息)。需要被丢弃的部分时,使用 fullseye.ledger.vol_euler_number.raw(...),或直接调用 volops.vol_euler_number。
• 底层返回: chi(b0-b1+b2)
二值体的欧拉示性数,并拆分为三个贝蒂数(物体・贯通孔・闭孔)。
> 以下的详细说明为原文 —— 摘要与标题已翻译。
`chi = b0 - b1 + b2 where b0 counts **separate objects**, b1`
counts tunnels (handles that pass right through) and `b2` counts
enclosed cavities. For porous media that split is the whole point:
`b1` is open, connected porosity — the paths a fluid can take — while
`b2 is closed porosity that no fluid reaches. A single chi` cannot
tell a foam with many tunnels from one with many sealed bubbles; the three
numbers can.
*connectivity* is `6, 18 or 26` for the foreground; the background
is counted with the complementary neighbourhood (`26 vs 6`), which is
what makes the pair of counts consistent — using the same neighbourhood for
both is the classical way to produce a set that is simultaneously connected
and disconnected.
Returns ``{"euler": chi, "objects": b0, "tunnels": b1, "cavities": b2,
"connectivity": connectivity}`. b1 is derived as b0 + b2 - chi`, so
it inherits the exactness of the other three.
HALCON's `euler_number` is 2-D (regions) only; there is no voxel
equivalent.
• 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。
• ct_porosity_and_fibre_morphometry — py -3.11 examples_3d/ct_porosity_and_fibre_morphometry.py
measurement 作为输入)vol_gaussian_psf · fuse_to_voxel · fresnel_reflectance · snell_angle
feature)sobel3d · hessian3d · curvature_maps · edt_jfa · vol_frangi · vol_local_std · vol_local_thickness · vol_orientation_coherence
*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.