riesz op• 데이터 종류: qimage → image2d
• 호출: import fullseye as fs; fs.ledger.monogenic_orientation(qimage, display: 'bool' = False) -> 'np.ndarray'(구현을 직접 호출하려면 import quatimage; quatimage.monogenic_orientation(qimage, display: 'bool' = False) -> 'np.ndarray', 원장에서 가져오려면 opsquat.get("monogenic_orientation"))
모노제닉 신호의 국소 방위 atan2(R2, R1). → (H, W).
> 아래 상세 설명은 원문입니다 —— 요약과 제목은 번역되어 있습니다.
Radians in [0, pi): an orientation is defined modulo pi (a grating at 10 degrees and one at 190 degrees are the same grating), and the value is folded into that range rather than left in (-pi, pi] where the same structure would read as two different numbers on either side of a contrast reversal. display=True maps it to [0, 1].
Continuous, not quantised — the angle is read directly from two filters, for any angle, where a steerable bank with K orientations interpolates between its K. Measured against eight grid-exact grating orientations the error is at most 3.6e-15 rad, including the obliques. (Whether that buys anything downstream is a separate question, and the measured answer is mostly *no* — see riesz_displacement.)
Where it is undefined, and the mask is not the one you expect. The orientation dies where the *Riesz vector* dies, which is at every even-symmetric point — local phase 0 or pi, the crest of a bright or dark line — and the amplitude is at full strength there. Measured on a 45-degree grating, the worst orientation error over the whole frame is 0.2764 rad, at a pixel where |R| = 6.8e-16 and monogenic_amplitude reads 1.0000. So masking on the amplitude does not protect you; mask on hypot(q[..., 1], q[..., 2]), the Riesz magnitude. With that mask the error over the same eight orientations is at most 3.6e-15 rad.
Where the Riesz vector is exactly zero, atan2(0, 0) = 0 is returned — a *value*, not a measurement.
Raises ValueError: the input is not a valid quaternion field, or its k component is non-zero; *display* is not a bool.
• quaternion_monogenic 패밀리 가이드
• 샘플 데이터 카탈로그(DL URL / 라이선스) —— 2-D 는 skimage.data(BSD/public)+ 합성, 3-D 는 실데이터 소스(Stanford/PDS 등)의 DL URL.
• 연산자의 내력·참고문헌 —— 이 연산자 족의 바탕이 된 연구/기법의 출처.
• 알고리즘의 정전(저자·연도)과 용도는 위의 패밀리 사용 가이드에 적혀 있습니다.
• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py
image2d 를 입력으로 받는 것)riesz_transform · monogenic_signal
riesz)riesz_transform · monogenic_signal · monogenic_amplitude · monogenic_phase
*Provenance: quatimage.py — QUAT 연산자 레지스트리. 이 op 노트는 tools/opdocs.py md 가 자동 생성합니다(직접 편집하지 마세요).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.