xsk_struct_coherence — 2D texture op

Data kinds: imageimage

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

Usage

Structure tensor coherence (consistency of orientation).

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

skimage.feature.structure_tensor で勾配の 2 次モーメント行列を計算し、

その固有値 `l1>=l2 から (l1-l2)/(l1+l2)` を求める。値は 1 に

近いほど局所的に強い一方向の構造(エッジ・線状パターン)、0 に近い

ほど等方(平坦またはコーナー状)であることを示す。

`a が構造テンソルの平滑化スケール sigma` を 0.5〜2.5 に振る。

`b` は未使用。テクスチャの方向性の強さを測る特徴として使う

(向き自体は返さない)。

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_freqpy -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).*

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