region op• Data kinds: region → region
• Call: fullseye.apply(img, "morph_skeleton", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: morph_skeleton (the HALCON reference is a useful guide to its meaning and parameters)

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*
Extracts the skeleton of a region. The implementation uses skimage's `skeletonize` (a Zhang-Suen-type iterative thinning algorithm); a and b are unused.
> The detailed description below is the original text — the summary and the headings are translated.
HALCON の `morph_skeleton`(構造要素による反復収縮とその差分から求める形態学的スケルトン)とはアルゴリズムが異なる近似 —— 同じ「1 画素幅の骨格」という結果を目指すが、生成過程・端点の扱いなどが morph_skeleton の定義と一致するとは限らない。
• gallery2d_region family guide
• 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.
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 morph_skeleton 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_region — py -3.11 examples/gallery2d_region.py
region as input)identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small
region)reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small · invert_region
*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.