level_set_reinit — SEGMENTATION `contour` op

• Data kinds: mask → table

• Call: import fullseye as fs; fs.ledger.level_set_reinit(phi, *, method: 'str' = 'sussman', n_iter: 'int' = 100, dt: 'float' = 0.5, band: 'float' = 3.0) -> 'Dict[str, object]' (to call the implementation directly, import segcontour; segcontour.level_set_reinit(phi, *, method: 'str' = 'sussman', n_iter: 'int' = 100, dt: 'float' = 0.5, band: 'float' = 3.0) -> 'Dict[str, object]'; from the registry, opssegmentation.get("level_set_reinit"))

Usage

Turns φ (inside where φ < 0) into the signed distance function of the same zero level set (level_set_reinit).

> The detailed description below is the original text — the summary and the headings are translated.

`method="sussman"` = φ_τ + S(φ0)(|∇φ| − 1) = 0(Sussman–Smereka–Osher 1994)を Godunov の風上差分で

`n_iter 回(刻み dt` ≤ 0.5)。界面に接する格子点(4 近傍で符号が変わる)は Russo–Smereka 2000 の subcell fix:

D = φ0 / Δφ0(Δφ0 = 中心差分の勾配の大きさと片側差分の最大)へ緩和させ、零等高線を動かさない。

`method="edt"` = マスク φ < 0 から距離変換で作る符号付き距離(第 2 実装。零等高線は画素の中心の中間に量子化され、

最大で半画素動く)。bool のマスクを渡すと edt の符号付き距離を φ0 として使う。

返り値: `phi、grad(|φ| ≤ band での |∇φ| の 10/50/90 % 点と画素数)、grad_before`(同、入力)、

`zero_hausdorff(前後の零等高線の Hausdorff、画素)、method、n_iter`。

Detailed usage guide

• halcon_segmentation family guide

Background guides (the physics and conventions behind this op)

• active_contours_and_level_sets — 変分・動的輪郭とレベルセット — どの輪郭がどこで止まり、何を保証するか

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_active_contours — py -3.11 examples/poc_active_contours.py

Ops the type connects to (they accept `table` as input)

class_ndim_norm

Same category (`contour`)

snake_evolve · gvf_field · chan_vese_energy · chan_vese_evolve · morph_chan_vese · morph_geodesic_ac · edge_stop_g · drle_evolve

*Provenance: segcontour.py — SEGMENTATION operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

level_set_reinit — SEGMENTATION contour op