contour_point_num_xld — 2D contour op

Data kinds: contourfeature

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

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

Usage

Selects the contour with the most points among a group of XLD contours and returns its vertex count normalized by 500 into [0,1] (saturating at 1.0 for 500 or more points). a and b are unused. Returns 0 if there are no contours.

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

HALCON の `contour_point_num_xld`(XLD 輪郭に含まれる点の実数をそのまま返す演算)とは異なり、この実装は点数そのものではなく 500 点でスケーリングした比率を返す近似(feature sort が [0,1] 想定の値を運ぶ契約のため)。

Detailed usage guide

gallery2d_contour_measure 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.

Runnable examples (verified samples that actually call this op)

gallery2d_contour_measurepy -3.11 examples/gallery2d_contour_measure.py

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

identity

Same category (contour)

select_contours · smooth_contours · fit_line_contours · contours_to_region · sk_find_contours · edges_sub_pix · lines_gauss · select_contours_xld


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

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.