xcv_grabcut — 2D segmentation op

Data kinds: imageregion

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

Usage

Automatic foreground/background separation via GrabCut (iterative graph cut).

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

画像中央 70%×70%の固定矩形を「たぶん前景」の初期領域として与え、

色分布の GMM とグラフカットで前景/背景を反復的に分離する

(`cv2.GC_INIT_WITH_RECT`)。「確実な前景」と「たぶん前景」の画素を

合わせて前景 region として返す。

`a` が反復回数を 2〜5 回の範囲で振る(多いほど収束するが遅い)。

`b` は未使用。矩形が画像中央固定のため、被写体が縁に寄っている

画像では抽出に失敗しやすい。

Detailed usage guide

gallery2d_segmentation 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_segmentationpy -3.11 examples/gallery2d_segmentation.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 (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.