vol_count — 2D features op

Data kinds: volumefeature

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

*No figure: this op takes volume as input. A Studio program starting from an image cannot reach that type — see the runnable examples below for how it is used.*

Usage

A feature that returns the number of connected components (blobs) in a 3D volume. No corresponding HALCON op is specified.

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

`a, b は未使用。しきい値は 0.5 に固定(v > 0.5 で二値化してから scipy.ndimage.label)。連結性は scipy の既定構造要素(面で接する 6 近傍相当)で、稜・頂点だけで接する(26 近傍でしか繋がらない)ボクセルは別ブロブとして数えられる——2-D の _blob_count` が HALCON パリティのため 8 連結を明示指定しているのとは対照的に、こちらは既定のまま連結性を明示していない。

Detailed usage guide

gallery2d_features 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_featurespy -3.11 examples/gallery2d_features.py

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

identity

Same category (features)

blob_count · area_frac · count_contours · total_length · sk_euler · sk_entropy_feat · sk_blur_effect · cv_cc_count


*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.