arrow — ANNOTATE `pointer` op

• Data kinds: image2d → image2d

• Call: import annotate; annotate.arrow(img, p0, p1, color='emphasis', width=2, head_len=12.0, head_width=9.0, scheme='okabe_ito', style=None) (or opsannotate.get("arrow"))

Usage

An arrow from `p0 to p1 (the shaft via :func:imagedraw.draw_line`, the head filled).

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

Parameters

----------

p0, p1 : (x, y)

起点・先端。x=col, y=row。

head_len, head_width : float

矢じりの長さ・幅[px]。`0` で線分のみ。軸より矢じりが長い短距離の

矢印では、矢じりを軸長の 8 割まで相似に縮める(そうしないと

矢じりの根元が起点の手前に来て、軸が逆向きに描かれる)。

style : dict or None

軸線を引く :func:imagedraw.draw_line への素通し引数(破線など)。

Returns

-------

ndarray

Raises

------

ValueError

端点が非有限/一致、負の太さ・矢じり寸法、両端とも画像の外。

Detailed usage guide

• figure_annotation family guide

Background guides (the physics and conventions behind this op)

• dataset_conventions — 学習データセット規約の知識 — COCO / YOLO / VOC と外観検査での落とし穴

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)

• annotate_gallery — py -3.11 examples/annotate_gallery.py

Ops the type connects to (they accept `image2d` as input)

text_box · leader_line · label_points · crosshair · legend_box · color_bar · scale_bar · axes_frame

Same category (`pointer`)

leader_line · label_points · crosshair

*Provenance: annotate.py — ANNOTATE operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

arrow — ANNOTATE pointer op