text_line_orientation — MV text op

• Data kinds: image2d → scalar

• Call: import fullseye as fs; fs.ledger.text_line_orientation(image, max_angle=30.0, step=0.25) (to call the implementation directly, import mvtext; mvtext.text_line_orientation(image, max_angle=30.0, step=0.25); from the registry, opsmv.get("text_line_orientation"))

• HALCON equivalent: text_line_orientation (the HALCON reference is a useful guide to its meaning and parameters)

• GPU: none (CPU reference implementation only)

Usage

Find the tilt of text lines in degrees by maximizing the sharpness of the projection.

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

行の射影は傾きが合うと階段が最も鋭くなる。その鋭さ(隣り合う射影の差の 2 乗和)を -max_angle .. max_angle で走査する。角度の向きはこの repo の矩形と同じで、右へ進むと行が増える向きが正。インクが無い画像は 0.0 を返す(理由: 傾きを決める手がかりが無い)。空の入力(image が 0 要素)は ValueError。

Args:

image: 灰色画像か bool の領域 (H, W)。灰色は Otsu のしきい値で二値にする。

max_angle: 走査の範囲(度、> 0)。

step: 走査の刻み(度、> 0)。

Returns:

傾き(度)。

Detailed usage guide

• machine_vision_classics 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)

• machine_vision_tour — py -3.11 examples/machine_vision_tour.py

• poc_real_typewritten_ocr — py -3.11 examples/poc_real_typewritten_ocr.py

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

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Same category (text)

text_line_slant · segment_characters · select_characters


*Provenance: mvtext.py — MV 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.