hx_smallest_rect1_xld — 2D `halcon_ext` op

• Data kinds: contour → feature

• Call: fullseye.apply(img, "hx_smallest_rect1_xld", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: smallest_rectangle1_xld (the HALCON reference is a useful guide to its meaning and parameters)

hx_smallest_rect1_xld: 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):

▸ hx_smallest_rect1_xld: stages (docs site)

Usage

The area ratio of the axis-aligned bounding box of all contour points (a feature).

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

contour dict の全点をまとめ、行方向・列方向それぞれの `max - min`(外接軸並行矩形の高さ・幅)の積を

画像面積 `H*W で割った値を np.float64` で返す。

• `a, b` は未使用。

• 点が無ければ 0.0。1 点だけ、または全点が同一行/列でも幅が 0 になり 0.0(`+1` の画素補正はしない)。

全 contour をまとめた 1 つの矩形なので、離れた contour が 2 つあると間の空白も面積に入る。向きを持つ

最小面積矩形は `hx_smallest_rect2_xld、region に対する軸並行外接矩形は smallest_rectangle1`。

Detailed usage guide

• gallery2d_halcon_ext 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
sk_find_contours 0.50 0.50
hx_smallest_rect1_xld 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py

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

identity · feature_to_img

Same category (`halcon_ext`)

hx_gen_circle · hx_gen_ellipse · hx_gen_rectangle2 · hx_gen_checker_region · hx_gen_grid_region · hx_gabor · hx_fit_surface1 · hx_fit_surface2

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

hx_smallest_rect1_xld — 2D halcon_ext op