polarization op• 資料種類:polsweep → image2d
• 呼叫: import fullseye as fs; fs.ledger.polarization_dolp_map(images, angles_deg=(0.0, 45.0, 90.0, 135.0), max_violation_frac=0.0)(要直接呼叫實作,import specularity; specularity.polarization_dolp_map(images, angles_deg=(0.0, 45.0, 90.0, 135.0), max_violation_frac=0.0);從台帳取用則 opsspecular.get("polarization_dolp_map"))
• GPU:無(僅 CPU 參考實作)
逐像素的線偏振度。→ [0, 1] 的 (H, W)。
> 以下的詳細說明為原文 —— 摘要與標題已翻譯。
sqrt(S1^2 + S2^2) / S0, from the same sinusoid fit as polarization_separate. It answers the question that decides whether a polariser is worth mounting at all: 1 means the light at that pixel is fully linearly polarised and a crossed analyser extinguishes it completely, 0 means the polariser will only cost you a stop of exposure.
Being a ratio, it is invariant to exposure: scaling every frame by 1e-4, 1e4 or 1e8 moves it by at most 3.9e-16 (measured), which is what makes it comparable across a production line where the lamps age. Not *bit*- identical — the least-squares fit rounds differently at a different scale — and the difference between "invariant" and "bit-identical" is the kind of claim this library measures rather than asserts.
Pixels with zero total radiance have no degree of polarisation (every ratio would be 0/0) and are returned as 0.0 rather than as NaN; that is a convention, and it is stated here because a NaN spreading into a thresholding routine is exactly the silent failure this library refuses.
★Dark pixels (2026-11-09): "zero" is measured against the noise — a pixel whose fitted mean a0 = S0/2 is at most POLAR_DARK_K (3) × the noise of the modulation amplitude (σ̂·√(v₁+v₂), one σ̂ for the image from the residuals of an N > 3 sweep) is returned as 0.0 too, i.e. where the DoLP's own noise would be 1/3 or more. DoLP is a ratio, and clipped sensor noise in a dark region (σ 0.001 of a scene peaking at 1) used to come back as DoLP 1.0 — "completely polarised", the opposite of the truth — on 72 % of the dark pixels once *max_violation_frac* let the image through. A 0 here means "not defined", not "unpolarised" — use polarization_stokes_map's lit to tell them apart. With three angles there is no residual and only S0 = 0 is 0 (noise-only dark pixels are not screened). One σ̂ assumes stationary noise; shot noise grows with the signal, so the floor is set by the typical pixel.
Raises ValueError: as polarization_separate.
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
• 演算法的正典(作者、年份)與用途見上面的族使用指南。
• example_polarization_metal — py -3.11 examples/example_polarization_metal.py
• perf_polarization_analyze — py -3.11 examples/perf_polarization_analyze.py
• poc_polarization_specular — py -3.11 examples/poc_polarization_specular.py
• polarization_camera_pipeline — py -3.11 examples/polarization_camera_pipeline.py
• specular_photometric — py -3.11 examples/specular_photometric.py
image2d 作為輸入)polarization_render · deflectometry_render · deflectometry_phase_to_slope
polarization)polarization_render · polarization_separate · polarization_stokes · polarization_stokes_map
*Provenance: specularity.py — SPECULAR 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.