sk_shape_index — 2D `texture` op

• Data kinds: image → image

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

Usage

Shape index. Represents local surface shape as a single scalar from -1 (spherical cup/pit) through 0 (saddle point) to +1 (spherical cap/dome), derived from the eigenvalues of the Hessian matrix -- a descriptor that summarizes the "orientation" of curvature.

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

HALCON に直接対応するものは無い。実装は `feature.shape_index(v, sigma=0.5+2.0*a) の NaN(平坦領域で未定義になる)を 0 に置き換えてから signed01(符号付き応答の 0 を 0.5 に写像し、±最大値を 0/1 に写像する)で [0,1]` へ写した値 —— a は Hessian を計算する際のガウス微分の σ を 0.5〜2.5 に振る。b は未使用。

Detailed usage guide

• gallery2d_texture_freq 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_texture_freq — py -3.11 examples/gallery2d_texture_freq.py

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

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

Same category (`texture`)

std_filter · gabor · sk_frangi · sk_meijering · sk_hessian · sk_gabor · sk_lbp · sk_entropy

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

sk_shape_index — 2D texture op