spectral op• Data kinds: none → pairs (an op determined by its arguments alone — it takes no image or data input)
• Call: import fullseye as fs; fs.ledger.spectral_reflectance_from_material(material='NUT_KERNEL', particle_um=None, thickness_mm=10.0, background_reflectance=0.05, water_fraction=None, carbon_black_fraction=0.0, internal_reflectance=0.6, wl_min_nm=900.0, wl_max_nm=2500.0, n_points=321) (to call the implementation directly, import spectralrad; spectralrad.spectral_reflectance_from_material(material='NUT_KERNEL', particle_um=None, thickness_mm=10.0, background_reflectance=0.05, water_fraction=None, carbon_black_fraction=0.0, internal_reflectance=0.6, wl_min_nm=900.0, wl_max_nm=2500.0, n_points=321); from the registry, opsoptics.get("spectral_reflectance_from_material"))
Diffuse reflectance spectrum of a grain or fragment from the material table's near-infrared absorption bands (the observed-object side).
> The detailed description below is the original text — the summary and the headings are translated.
1. α(λ) = materials.material_nir_absorption(帯の重ね合わせ、水は表の Hale & Querry) + カーボンブラック(materials.carbon_black_absorption、*carbon_black_fraction* 質量分率)。
2. S = S_ref · (d_ref / *particle_um*)(散乱は粒径に反比例、S_ref と d_ref は材料の表の値)。
3. 層の拡散反射 R_KM = kubelka_munk_reflectance(既定は厚さ 10 mm の粒が *background_reflectance* の上に載る —— 薄い破片ほどベルトが透ける。None なら無限厚で、背景は効かない)。
4. 界面: Saunderson (1942) の補正 R = r_s + (1 − r_s)(1 − r_i) R_KM / (1 − r_i R_KM)、r_s = ((n − 1)/(n + 1))²(表の n_nir の垂直入射 Fresnel)、r_i = *internal_reflectance* (中から見た拡散光の内部反射、0.4〜0.6 が典型)。鏡面の光沢は波長に平坦なので、黒い樹脂でも 4〜5 % の平らな反射が残り、帯の形が消える。
返り値: pairs(λ nm, R)。粒が粗い・厚いほど暗く帯が深く、細かいほど明るく浅い(Kubelka–Munk の S 依存)。
出典: Kubelka (1948)、J. L. Saunderson, J. Opt. Soc. Am. 32, 727 (1942)、帯の表は materials.NIR_BAND_MODELS の注。
Every optics op validates its input before computing (nothing slips through silently):
• Units are baked into the argument name — _mm / _um / _deg / _mrad. Confusing mm with µm does not crash; it yields a plausible-looking wrong answer, so the name prevents it. Nothing here guesses the unit from the magnitude.
• Strings raise ValueError — float('50') succeeds, so an unparsed configuration value would slip through as a length (measured: thin_lens('50', '200') returned a plausible 66.667 mm). bool is refused too, as the implicit promotion True == 1.
• complex / masked arrays raise ValueError (real-valued slots only; silently dropping the imaginary part or peeling off the mask is refused). NaN/Inf raises ValueError on every input.
• Division by zero and its relatives are refused by name: focal length 0, radius of curvature 0, refractive index <= 0, a fully opaque aperture (all zeros, so the normalisation is 0/0), a PSF whose sum is <= 0, a Stokes vector with S0 = 0, and an object sitting at the front focal point (the image is at infinity).
• Only two ops return a non-finite value, and both state it as a contract: depth_of_field returns far_mm = inf beyond the hyperfocal distance (that is what the hyperfocal distance means), and gaussian_beam returns wavefront_radius_mm = inf at the waist (the radius of curvature of a plane wavefront). Both also return a finite companion (far_is_infinite / curvature_per_mm). Any other silent NaN/Inf is detected internally and raises ValueError — "float64 overflowed" and "the answer is infinite" are different claims, so the first is never returned wearing the face of the second.
• Size caps: generated grids are capped by optics.MAX_GRID (4096); supplied fields/PSFs/apertures by optics.MAX_FIELD_ELEMENTS (2^24); ABCD element chains by optics.MAX_SYSTEM_ELEMENTS (1024); Zernike by MAX_ZERNIKE_TERMS (512) / MAX_ZERNIKE_ORDER (40) / MAX_ZERNIKE_BASIS (2^25). This closes, fail-closed, the paths where a small argument triggers a huge internal allocation (measured: n_max=40 × 4096² needs 108 GB).
• Physically impossible states are refused too: a Stokes vector with degree of polarisation > 1, negative transmittance, negative intensity, and invalid Zernike indices such as n-|m| odd.
• 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.
• poc_hyperspectral_foreign_matter — py -3.11 examples/poc_hyperspectral_foreign_matter.py
pairs as input)mtf50 · energy_to_photons · spectral_product · spectral_integral · spectral_stats · kubelka_munk_reflectance · hyperspectral_capture · film_thickness_fft
spectral)blackbody_spectrum · cie_illuminant_a · led_spectrum · bandpass_spectrum · silicon_photodiode_qe · energy_to_photons · spectral_product · spectral_integral
*Provenance: spectralrad.py — OPTICS 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.