texture op• Data kinds: image → image
• 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])
*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*
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)。
• gallery2d_texture_freq family guide
• 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.
The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.
xsk_struct_coherence 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_texture_freq — py -3.11 examples/gallery2d_texture_freq.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
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.