normalize — SHAPE2D descriptor op

• Data kinds: efdmodel → matrix

• Call: import fourierdesc; fourierdesc.normalize(model, size_invariant=True) (or opsshape2d.get("normalize"))

Usage

> This operator's description has not been translated yet. The original text follows as it is.

EFD 係数を「正準ポーズ」の係数へ変換する(第1高調波を基準に整列)。

Kuhl–Giardina の正準化: (1) 第1高調波の位相で 始点 の任意性を除去、(2) 第1

楕円の長軸を基準軸へ回して 向き を揃え、(3) 第1高調波の長軸長で割って 大きさ

を揃える。複数形状を重ねる/平均する等の「正準ポーズ再構成」向け。

注意(honest): 第1高調波がほぼ 円形(長軸≈短軸)の形状では位相 (theta/psi) が

悪条件で不安定になる。不変マッチングには本関数でなく :func:invariants /

:func:descriptor_distance(特異値ベース)を使うこと。

Detailed usage guide

• shape_description_2d 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)

• piv_flow_from_particles — py -3.11 examples/piv_flow_from_particles.py

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

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Same category (descriptor)

elliptic_fourier · reconstruct · invariants · descriptor_distance · fourier_smooth · from_xld

*Provenance: fourierdesc.py — SHAPE2D 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.