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"))
Edge-stopping function g = 1 / (1 + |∇(G_σ * I)|² / k²) (the p = 2 form of Caselles–Kimmel–Sapiro 1997) (edge_stop_g).
sigma = standard deviation of the Gaussian (0 means central differences without smoothing), k = gradient scale (k = 1 gives g = 1/(1 + |∇G_σ*I|²)). It depends on the image value range: Li et al. 2010's distributed example uses k = 1 on 0-255 images, so for a [0, 1] image k = 1/255 gives the same behaviour.
Returns: g (0 < g ≤ 1, 1 where flat), grad_mag, g_min / g_max, sigma, k.
Gate: g ∈ (0, 1] — denominator ≥ 1, g ≡ 1 on a flat image (gradient 0).
• halcon_segmentation family guide
• active_contours_and_level_sets — Variational and active contours, level sets — which contour stops where, and what it guarantees
• 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.
• poc_active_contours — py -3.11 examples/poc_active_contours.py
table as input)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.