scale_select_std — 2D texture op

Data kinds: imageimage

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

scale_select_std: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

*The output is shown in a viridis-like pseudo-colour (dark purple = low, yellow = high) so that a field of quantities — distance, phase, orientation, depth — can be read.*

Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):

scale_select_std: knob a sweep (docs site)

Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):

scale_select_std: knob b sweep (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

scale_select_std: other inputs (docs site)

*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*

Usage

> This operator's description has not been translated yet. The original text follows as it is.

画素ごとに窓の大きさを選ぶ局所標準偏差(Lepski / ICI 規則)。

窓を広げるほど推定は安定するが(相対標準誤差 `1/sqrt(2(n-1))`)、縁がにじんで

分解能が落ちる —— 大きさを 1 つ選ぶ限りこの矛盾は解けない。解き方は「時間でも

場所でもなく場所ごとに別の答えを持つ」こと: 小さい窓から順に、推定値の信頼区間が

交わり続ける間だけ窓を広げ、交わらなくなった 1 つ手前で止める。平坦な所では大きな窓

(安定)、縁の近くでは小さな窓(にじまない)が自動で選ばれる。

`a が試す窓の上限(3,5,7,9,11,13,15 のどこまでか)、b` が信頼区間の倍率

`gamma(1.0〜3.0)。gamma` を大きくすると窓が伸びやすくなる(安定寄り)。

**`local_std との関係**: local_std` は窓を固定する。平坦部の推定を締めたくて

窓を広げると縁がにじむ、という取引をこちらは場所ごとに解く。**縁の鋭さを保ったまま

平坦部の誤差だけ下げられる**のが取り柄で、代わりに計算量が窓の数だけ増える。

適用条件: (1) 「交わるか」の判定は誤差限界が正しいことに依存する —— 白色雑音

でない(空間相関のある)雑音では窓が伸びすぎる。(2) `gamma` が小さすぎると常に

最小窓が選ばれ、`local_std` の 3x3 と同じになる(効いていないときの見分け方)。

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.

Try it in Studio

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.

scale_select_std 0.50 0.50

▸ Load this pipeline  ·  Load & run

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 · local_bimodality · local_std · bootstrap_std_error · structure_tensor_orientation · structure_tensor_coherence · gabor · sk_frangi


*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.