sigma_image — 2D `smoothing` op

• Data kinds: image → image

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

• HALCON equivalent: sigma_image (the HALCON reference is a useful guide to its meaning and parameters)

Usage

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

シグマフィルタによる非線形平滑化。中心画素値に近い(`|x-mean|<σ`)

近傍画素だけを平均する ―― エッジ付近では反対側の階調が平均に混ざらないため、

平均フィルタよりエッジを保ちやすいノイズ除去になる。HALCON の

`sigma_image`（Non-linear smoothing with the sigma filter.）に相当。

`a が窓の一辺を {3,5,7,9} で振る(内部の平均計算にも使う)。b` が

許容帯域(シグマ、0.05〜0.4)を振る。両方が使われる。近傍がすべて帯域外の

画素は元の値のまま残る。

Detailed usage guide

• gallery2d_smoothing_rank 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_smoothing_rank — py -3.11 examples/gallery2d_smoothing_rank.py

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

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

Same category (`smoothing`)

gaussian · mean_box · bilateral · unsharp · sk_tv · sk_wavelet · sk_rolling_ball · sk_nlm

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

sigma_image — 2D smoothing op