select_largest — 2D `region` op

• Data kinds: region → region

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

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

Usage

Keeps only the connected region with the largest area. Equivalent to HALCON's `select_shape_std` (Select regions of a given shape.).

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

`a, b は未使用（常に「最大」を選ぶ）。連結成分ラベリング後、画素数が最大の 1 成分だけを 1、それ以外を 0 にする。入力に前景が無ければ全 0 を返す。HALCON の select_shape_std` は面積以外の形状基準（円形度等）や複数選択にも対応するが、この実装は面積最大の単一選択のみ。

Detailed usage guide

• gallery2d_region 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_region — py -3.11 examples/gallery2d_region.py

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

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

Same category (`region`)

reg_erode · reg_dilate · reg_open · reg_close · fill_holes · remove_small · invert_region · dist_transform

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

select_largest — 2D region op