area_opening_attr — SEGMENTATION graph op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.area_opening_attr(image, threshold: 'float' = 16.0, *, attribute: 'str' = 'area', connectivity: 'int' = 4) -> 'Dict[str, object]' (to call the implementation directly, import seggraph; seggraph.area_opening_attr(image, threshold: 'float' = 16.0, *, attribute: 'str' = 'area', connectivity: 'int' = 4) -> 'Dict[str, object]'; from the registry, opssegmentation.get("area_opening_attr"))

Usage

Attribute opening (Salembier et al. 1998): removes the component-tree nodes whose attribute < `threshold` and sets each pixel to the value of its nearest ancestor with attribute ≥ threshold (area_opening_attr).

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

`attribute = "area"(画素数、skimage の area_opening と同じ「面積が閾値未満の明るい構造を消す」)か "diameter"`

(外接矩形の長い辺、skimage の diameter_opening)。どちらも 2 値の集合の 増加する属性なので、結果は代数的開放 =

冪等・反拡大・増加。成分の中の最大値に依る「高さ」は集合の属性でなく(h-maxima と同じく)冪等にならないので載せない

(実測で 2 回目に値が変わった)。

返す: `image(開放の結果)、n_nodes_kept / n_nodes、removed`(値が下がった画素の数)。

Detailed usage guide

• halcon_segmentation family guide

Background guides (the physics and conventions behind this op)

• graph_hierarchy_and_thresholds — グラフ・階層・閾値の定理でつくる分割 — 何が厳密で、どこで割れ方が倒れるか

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)

• poc_graph_hierarchy_segmentation — py -3.11 examples/poc_graph_hierarchy_segmentation.py

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

class_ndim_norm

Same category (graph)

graph_cut_binary · alpha_expansion · statistical_region_merging · max_tree · quasi_flat_zones · alpha_tree · hierarchical_watershed · ultrametric_contour_map


*Provenance: seggraph.py — SEGMENTATION 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.