reflection_axis — AOI `symmetry` op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.reflection_axis(image, angle_step=2.0, offset_search=4.0) (to call the implementation directly, import symmetry2d; symmetry2d.reflection_axis(image, angle_step=2.0, offset_search=4.0); from the registry, opsaoi.get("reflection_axis"))

• GPU: none (CPU reference implementation only)

Usage

Estimates the angle and offset of the reflection axis of a line-symmetric 2-D image.

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

Parameters

image : array-like, shape (H, W)

グレー画像または region。回転済みの試験像はグレーを補間してから二値化する。

angle_step : float, default 2.0

粗い角度走査の刻み [degree]。範囲は [0.25, 15]。最良点は連続最適化で詰める。

offset_search : float, default 4.0

エッジ対中心から軸法線方向に探索する半幅 [px]。範囲は [0.5, min(H,W)/3]。

Returns

dict

angle_deg は +col 軸から +row 方向へ測る [0,180) 度、offset_px は

画像中心から軸の法線方向への符号付き距離。score、2位との差 margin も返す。

Notes

線形補間した鏡像との正規化絶対差を最小化する。定数入力、外側エッジ対が足りない入力は ValueError。円・正方形・回転対称と線対称を併せ持つ図形では軸が多義で、小さい margin がその警告になる。画像外で切れた対象や反射で等価な内部模様も一意な軸を保証しない。

Liu et al., Computational Symmetry in Computer Vision and Computer Graphics, FnT CGV 5(1-2), 2010.

Detailed usage guide

• aoi_frontend 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)

• (none yet)

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

symmetry_difference_map · symmetry_score

Same category (`symmetry`)

center_from_symmetric_edges · rotational_symmetry · symmetry_difference_map · symmetry_score

*Provenance: symmetry2d.py — AOI operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

reflection_axis — AOI symmetry op