hx_dist_rect2_points — 2D `halcon_ext` op

• Data kinds: contour → feature

• Call: fullseye.apply(img, "hx_dist_rect2_points", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: dist_rectangle2_contour_points_xld (the HALCON reference is a useful guide to its meaning and parameters)

hx_dist_rect2_points: 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_dist_rect2_points: stages (docs site)

Usage

The mean normalised distance of the contour points from the centre of the minimum-area oriented rectangle (a feature).

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

全 contour の点をまとめ、点の重心からの各点のユークリッド距離の平均を `max(H, W)` で割って 1 で頭打ちした

`np.float64` を返す。

• `a, b` は未使用。

• 点が 3 個未満なら 0.0。

注意: 名前は最小面積外接矩形の中心からの距離だが、現実装は矩形を求めず点群の重心を中心にしている。

点が偏っている場合(弧が欠けた輪郭など)は矩形中心と重心がずれるため、名前どおりの値にはならない。

実質は「重心からの平均半径」で、`hx_moments_any_xld`(二乗平均)の 1 乗版にあたる。矩形そのものは

`hx_smallest_rect2_xld / hx_fit_rectangle2_contour`。

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_dist_rect2_points 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_dist_rect2_points — 2D halcon_ext op