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

*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).*
Chan-Vese segmentation. An active contour model that iteratively moves a level set so that the brightness variance within each region is minimized, allowing detection of regions even for objects without sharp edges.
> The detailed description below is the original text — the summary and the headings are translated.
HALCON に直接対応するものは無い。実装は `segmentation.chan_vese(v, mu=0.1+0.4*a, max_num_iter=60)` —— a は'edge length' 重み mu を 0.1〜0.5 に振る(大きいほど輪郭が丸く滑らかになり細部を無視しやすくなる)。反復回数は 60 に固定。b は未使用。初期レベルセットは既定の 'checkerboard'(チェッカーボード状)。
• gallery2d_segmentation 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.
sk_chan_vese 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_segmentation — py -3.11 examples/gallery2d_segmentation.py
region as input)identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small
segmentation)threshold · otsu · canny · adaptive_gauss_thresh · sk_otsu · sk_li · sk_yen · sk_sauvola
*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.