gen_region_polygon_xld — 2D contour op

• Data kinds: contour → region

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

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

Usage

Converts an XLD contour (a polygon's vertex sequence) into a region (pixel mask). Plots contour points onto the nearest pixels, then thickens and connects the lines with `1+2a` rounds of binary dilation. b is unused.

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

HALCON の `gen_region_polygon_xld`（XLD 多角形の内部を塗りつぶした region を生成する演算）とは異なり、この実装は多角形の内部を塗りつぶすのではなく、輪郭線そのものを膨張させて太らせるだけの近似 —— 閉じていない輪郭や自己交差する輪郭では本来の内部塗りつぶしと結果が食い違う。

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_measure — py -3.11 examples/gallery2d_contour_measure.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 (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.