r2_partition_rectangle — 2D `region` op

• Data kinds: region → region

• Call: fullseye.apply(img, "r2_partition_rectangle", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

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

r2_partition_rectangle: 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.*

Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):

▸ r2_partition_rectangle: knob a sweep (docs site)

*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_partition_rectangle: stages (docs site)

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

▸ r2_partition_rectangle: other inputs (docs site)

Usage

Split the region bbox into an NxN grid; keep cells overlapping the region.

> 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を `N x N` の格子に等分し、領域と 1 画素でも重なる

セルを丸ごと 1.0 で塗ったマスクを返す。`N = 2 + int(a*4) で a=0` → 2、

`a=1 → 6 分割(a` は [0,1] に clip)。セル境界は

`numpy.linspace(top, bottom+1, N+1)` を整数化したもので、bbox がセル数より

小さいと幅 0 のセルが生じ、そのセルはスキップされる。`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「領域を

覆うセルの和」なので入力領域を必ず含み、bbox の外は塗られない。中身が凸で

bbox いっぱいに詰まった領域では全セルが該当し、`a` を変えても出力は bbox

そのものになる。孔や凹みが大きい領域で初めて格子の粗さが見える。用途は

粗いタイル分割(局所処理の窓決め)や占有パターンの粗視化。隣接セルは

つながって 1 つの塊になるため、セル単位で分けて扱う用途には向かない。

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_partition_rectangle 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_partition_rectangle — 2D region op