feature op• 資料種類:voxel → measurement
• 呼叫: import fullseye as fs; fs.ledger.vol_euler_number(vol_binary, connectivity=26)(要直接呼叫實作,import volops; volops.vol_euler_number(vol_binary, connectivity=26);從台帳取用則 ops3d.get("vol_euler_number"))
• 經台帳呼叫的回傳值: fullseye.ledger.vol_euler_number(...) 只回傳**宣告的 out 型別 measurement 的值**(底層函式還會回傳輔助資訊)。需要被捨棄的部分時,請用 fullseye.ledger.vol_euler_number.raw(...),或直接呼叫 volops.vol_euler_number。
• 底層回傳: chi(b0-b1+b2)
二值體的尤拉示性數,並拆成三個貝蒂數(物體・貫通孔・閉孔)。
> 以下的詳細說明為原文 —— 摘要與標題已翻譯。
`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.
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
• ct_porosity_and_fibre_morphometry — py -3.11 examples_3d/ct_porosity_and_fibre_morphometry.py
measurement 作為輸入)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 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.