xsk2_inv_gauss_grad — 2D edges op

Data kinds: imageimage

Call: fullseye.apply(img, "xsk2_inv_gauss_grad", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

Inverse Gaussian gradient image (the edge-stopping function for Active Contour / GAC). Calls `skimage.segmentation.inverse_gaussian_gradient`.

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

a がエッジ感度 alpha(`50 + 150*a`、範囲 50〜200。大きいほど弱いエッジでも停止関数の値が下がる=止まりやすくなる)を振る。b は未使用。値はエッジで小さく(0 に近く)平坦部で 1 に近い——geodesic activecontour 系のセグメンテーションでエッジ停止項として使うことを想定した出力で、そのまま見た目のエッジ画像として使うと通常のエッジ検出とは明暗が逆に見える。

Detailed usage guide

gallery2d_edges family guide

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)

gallery2d_edgespy -3.11 examples/gallery2d_edges.py

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (edges)

sobel_mag · prewitt_mag · roberts_mag · dog · grad_dir · log · corner_response · sk_scharr


*Provenance: ops.py — 2D 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.