fullseye

monogenic_amplitude — QUAT riesz op

• データ種: qimage → image2d
• 呼び出し: import fullseye as fs; fs.ledger.monogenic_amplitude(qimage) -> 'np.ndarray' (実装を直接呼ぶなら import quatimage; quatimage.monogenic_amplitude(qimage) -> 'np.ndarray'、台帳から引くなら opsquat.get("monogenic_amplitude"))

使い方

Local amplitude sqrt(f^2 + R1^2 + R2^2) of a monogenic signal. → (H, W).

The local contrast at the signal’s scale, and the confidence map for :func:monogenic_phase / :func:monogenic_orientation, which mean nothing where this is at the rounding floor. Raw / unnormalised (a contrast is a metric quantity), in the same spirit as complexops.cx_magnitude.

For a unit-contrast grating at the band centre it is exactly 1.0 (measured spread 8.9e-16 over a 64x64 frame) and, unlike a squared oriented-filter response, it is isotropic: rotating the grating does not change it. Measured over eight grid-exact orientations the amplitude spans [0.99999999999999911, 1.0000000000000011] — a total spread of 2.0e-15 across all of them, which is the isotropy claim as a number.

Raises ValueError: the input is not a valid quaternion field, or its k component is non-zero (see :func:_require_monogenic).

詳しい使い方ガイド

• quaternion_monogenic ファミリ ガイド

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py

型が繋がる次の op(image2d を入力に取れる)

riesz_transform · monogenic_signal

同カテゴリ(riesz)

riesz_transform · monogenic_signal · monogenic_phase · monogenic_orientation

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Provenance: quatimage.py — QUAT operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.

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