r2_union1 — 2D `region` op

• Data kinds: region → region

• Call: fullseye.apply(img, "r2_union1", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: union1 (the HALCON reference is a useful guide to its meaning and parameters)

r2_union1: 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.*

*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

Stages (the ops that come before → this op, left to right):

▸ r2_union1: stages (docs site)

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

▸ r2_union1: other inputs (docs site)

Usage

Union of all connected components into a single mask (OR of labels).

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

前景マスク(`> 0.5)を scipy.ndimage.label` で連結成分にラベル付けし、

`label > 0` を 1.0 に戻して 1 枚のマスクとして返す。全成分の和集合なので、

結果は「入力を 0/1 に正規化したもの」と同じになる(値の 2 値化と非有限値の

除去が実際の効果)。`a, b` は未使用。

返り値は入力と同形の float64 0/1 マスク。前景が無ければ全零。0.5 以下の

グレー値や NaN/Inf はすべて背景になる。複数のラベル値を持つラベル画像を

受けた場合もラベル番号の区別は消え、単一の前景マスクになる(ラベルごとに

取り出したいなら `r3_label_to_region`)。パイプライン上は「領域を 1 個の

オブジェクトとして扱う」ことを明示する位置づけで、成分単位の選別

(`select_shape / r2_sort_region`)はこの op より前に置く。

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.

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.

threshold 0.50 0.50
r2_union1 0.50 0.50

▸ Load this pipeline · Load & run

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 · select_largest · remove_small

Same category (`region`)

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

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

r2_union1 — 2D region op