grating_interf op• Data kinds: image2d → images
• Call: import fullseye as fs; fs.ledger.grating_stepping_simulate(transmission=None, dpc_rad=None, darkfield=None, n_steps=8, ref_visibility=0.25, ref_phase_rad=0.0, steps_per_period=None, flux=None, seed=0, shape=(64, 64)) (to call the implementation directly, import gratinginterf; gratinginterf.grating_stepping_simulate(transmission=None, dpc_rad=None, darkfield=None, n_steps=8, ref_visibility=0.25, ref_phase_rad=0.0, steps_per_period=None, flux=None, seed=0, shape=(64, 64)); from the registry, opsoptics.get("grating_stepping_simulate"))
• Return value through the ledger: fullseye.ledger.grating_stepping_simulate(...) returns only the declared out type images (the underlying function also returns auxiliary values). When you need what was dropped, use fullseye.ledger.grating_stepping_simulate.raw(...) or call gratinginterf.grating_stepping_simulate directly.
Builds a phase-stepping image stack (N, H, W) from three maps: transmission, differential phase and dark field (forward model).
> The detailed description below is the original text — the summary and the headings are translated.
各画素の k 枚目(k = 0..N−1)は I_k = flux·T·(1 + V0·D·cos(φ0 + φ − 2πk/P))。T = transmission(吸収)、φ = dpc_rad(縞の位相のずれ = 微分位相。屈折角 α とは φ = 2π d α/p2)、D = darkfield(可視度の比、1 = 散乱なし)、V0 = ref_visibility(試料なしの縞の可視度)、φ0 = ref_phase_rad(格子のむらによる基準の位相。スカラーか図)、P = steps_per_period (1 周期のステップ数。None は N = 1 周期を N 等分)。3 枚とも None なら試料なし(基準)の画像列になる: T = 1、φ = 0、D = 1。
flux: None なら雑音なしの期待値(flux = 1)。数を渡すと、T = 1 の画素の 1 枚あたりの平均光子数として Poisson 雑音を足した整数の計数を float で返す(seed で再現)。
返り値: (N, H, W) float64。grating_three_image_retrieve に試料ありと基準の 2 組を渡すと 3 枚が戻る。Raises ValueError: 図が 2-D でない / 形がそろわない / NaN・Inf、T < 0、D が [0, 1] の外、V0 が (0, 1] の外、n_steps が 3..256 の外、P ≤ 0、flux ≤ 0。
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.
• grating_interferometry — py -3.11 examples/grating_interferometry.py
• poc_grating_interferometry — py -3.11 examples/poc_grating_interferometry.py
images as input)film_thickness_map · grating_three_image_retrieve · grating_step_period_estimate · render_transport · separate_direct_global · micro_phase_decode
grating_interf)talbot_grating_design · grating_three_image_retrieve · darkfield_scatter_relation · talbot_carpet · talbot_source_visibility · grating_step_period_estimate · dpc_integrate
*Provenance: gratinginterf.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.