dyn_threshold — 2D segmentation op

Data kinds: imageregion

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

HALCON equivalent: dyn_threshold (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.

局所しきい値処理。局所平均(窓一辺 `_k(a)uniform_filter`)に

オフセット `(b-0.5)*0.4` を加えたものをしきい値として使う ―― 照明ムラの

ある画像でも局所的なコントラストで前景を抽出できる。HALCON の

`dyn_threshold`(Segment an image using a local threshold.)に相当。

`a が局所平均の窓サイズを、b` がオフセット(しきい値を上下に振る量)

を振る。両方が使われる。

Detailed usage guide

gallery2d_segmentation 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_segmentationpy -3.11 examples/gallery2d_segmentation.py

Ops the type connects to (they accept region as input)

identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small

Same category (segmentation)

threshold · otsu · canny · adaptive_gauss_thresh · sk_otsu · sk_li · sk_yen · sk_sauvola


*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.