r2_smallest_rectangle1 — 2D `region` op

• Data kinds: region → region

• Call: fullseye.apply(img, "r2_smallest_rectangle1", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

r2_smallest_rectangle1: 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_smallest_rectangle1: stages (docs site)

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

▸ r2_smallest_rectangle1: other inputs (docs site)

Usage

Axis-aligned bounding box (smallest_rectangle1).

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

領域の外接軸並行矩形(bounding box)をマスクとして描く。前景マスク(`> 0.5`)

の前景画素について行・列の最小/最大 `ys.min()..ys.max()`、

`xs.min()..xs.max() を取り、その範囲を 1.0 で塗る。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。出力は必ず入力

領域を含む。複数の連結成分があれば全成分をまとめて囲む 1 つの矩形になる

(成分ごとの bbox が欲しければ先に `r2_sort_region や select_largest` で

1 成分に絞る)。矩形の 4 隅の座標そのものは返さない(マスク表現)。孤立ノイズが

1 画素あるだけで矩形が大きく広がるので、前段で `remove_small` や

`opening_circle` を掛けておく。回転を許した最小面積矩形は

`r2_smallest_rectangle2、内接側は r2_inner_rectangle1`。

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_smallest_rectangle1 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_smallest_rectangle1 — 2D region op