edge_stop_g — SEGMENTATION contour op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.edge_stop_g(image, *, sigma: 'float' = 1.0, k: 'float' = 1.0) -> 'Dict[str, object]' (to call the implementation directly, import segcontour; segcontour.edge_stop_g(image, *, sigma: 'float' = 1.0, k: 'float' = 1.0) -> 'Dict[str, object]'; from the registry, opssegmentation.get("edge_stop_g"))

Usage

Edge-stopping function g = 1 / (1 + |∇(G_σ * I)|² / k²) (the p = 2 form of Caselles–Kimmel–Sapiro 1997) (edge_stop_g).

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

`sigma = ガウスの標準偏差(0 なら平滑化なしの中心差分)、k` = 勾配の尺度(k = 1 で g = 1/(1 + |∇G_σ*I|²))。

画像の値域に依存する: Li ら 2010 の配布例は 0〜255 の画像で k = 1 なので、[0, 1] の画像なら k = 1/255 が同じ挙動。

返り値: `g(0 < g ≤ 1、平坦で 1)、grad_mag、g_min / g_max、sigma、k`。

門: g ∈ (0, 1] —— 分母 ≥ 1、平坦な画像で g ≡ 1(勾配 0)。

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 · level_set_reinit · drle_evolve


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

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