hx_test_closed_xld — 2D `halcon_ext` op

• Data kinds: contour → feature

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

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

hx_test_closed_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.*

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

▸ hx_test_closed_xld: 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):

▸ hx_test_closed_xld: stages (docs site)

Usage

The fraction of contours that are closed (end-point distance below a threshold = closed; a feature).

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

contour dict の各 contour について、点数が 3 以上かつ始点と終点のユークリッド距離が `tol` 以下なら

「閉じている」と数え、閉じた contour の本数を全 contour 数で割った割合を `np.float64` で返す。

• `a → 許容距離 tol = 1 + a*4`(1〜5 画素)。

• `b` は未使用。

• contour が無ければ 0.0。

始点=終点を重複させて閉じる `close_contours_xld` の出力は距離 0 なので必ず閉と判定される。

`hx_clip_end_points や hx_clip_contours` で端を落とした後は開いた扱いになる。個々の contour がどれかは

返さない(割合のみ)。

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_test_closed_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_test_closed_xld — 2D halcon_ext op