vol_resize — 3D geom_transform op

• データ種: voxel → voxel

• 呼び出し: import fullseye as fs; fs.ledger.vol_resize(vol, factor=None, shape=None, order=1, spacing=None, mode='nearest', cval=0.0) (実装を直接呼ぶなら import volxform; volxform.vol_resize(vol, factor=None, shape=None, order=1, spacing=None, mode='nearest', cval=0.0)、台帳から引くなら ops3d.get("vol_resize"))

• 台帳経由の戻り値: fullseye.ledger.vol_resize(...) は宣言 out 型 voxel の値だけを返す(本体は補助情報も返す)。捨てられた側が要るときは fullseye.ledger.vol_resize.raw(...)、または volxform.vol_resize を直接呼ぶ。

• 本体の返り: spacing 付き時

使い方

ボリュームを新しい格子へ再標本化する(scipy.ndimage.zoom、セル意味論)。

> 以下の詳細説明は原文のままです —— 要約と見出しは訳出済み。

Exactly one of *factor* / *shape* selects the target grid:

• factor — a positive scalar or (fz, fy, fx); the output shape is round(dim * f) per axis (scipy's rule, each >= 1).

• shape — the exact output (D', H', W') (positive integers).

Sampling uses grid_mode=True (cell semantics): a voxel is a *cell*, so an integer upscale f maps input voxel i exactly onto the output block [f*i, f*(i+1)) (exact at order=0), and the volume's physical extent is preserved by the recomputed spacing — not the endpoint-aligned convention of scipy's grid_mode=False default.

*mode* / *cval* set how samples that fall outside the input cells (the outer half-voxel shell of every upscale at order >= 1) are filled. The default "nearest" extends the border voxel, so a constant volume resizes to the same constant and a ramp keeps its end values. Until 2026-09-03 the call was hard-wired to "grid-constant" with cval=0, which blended the outer shell toward 0 — an upscale x2 of an all-ones volume came back with min = 0.42 on its faces, an artefact that then leaked into every downstream measurement. Other accepted modes: "reflect", "mirror", "grid-mirror", "grid-wrap", and "grid-constant" (with *cval*) when a zero-padded border is genuinely wanted. "constant" / "wrap" are rejected with a hint (scipy needs the grid- variants here).

The return shape depends on *spacing*:

• spacing=None (default) — returns the resampled (D', H', W') float64 volume alone.

• *spacing* given ((sz, sy, sx) or a VolumeMeta) — returns a 2-tuple (out, new_spacing) where new_spacing = (sz * D/D', sy * H/H', sx * W/W'), so out.shape * new_spacing == vol.shape * spacing per axis: the physical size in millimetres is invariant. Keep the new spacing — every spacing-aware operator downstream needs it.

*order* is the spline degree (exact integer 0..5; 0 = nearest — the choice for masks / labels, 1 = trilinear — the grey-value default; >1 can overshoot, see the module notes). Shrinking aliases (no band-limiting) — mean-pool with volops.volume_downsample first for large reductions.

Raises ValueError when both or neither of *factor* / *shape* are given, or when the output would exceed MAX_VOXELS (checked before any allocation — a huge factor cannot balloon memory).

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• vol_geometry_transform — py -3.11 examples_3d/vol_geometry_transform.py

型が繋がる次の op(voxel を入力に取れる)

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

同カテゴリ(geom_transform)

vol_rotate · vol_affine


*Provenance: volxform.py — 3D operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

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