light_transport op• Data kinds: none → images (an op determined by its arguments alone — it takes no image or data input)
• Call: import fullseye as fs; fs.ledger.high_frequency_patterns(shape=(1, 256), period=8, kind='stripes', fill=0.5, n_shifts=None, complement=False) (to call the implementation directly, import lighttransport; lighttransport.high_frequency_patterns(shape=(1, 256), period=8, kind='stripes', fill=0.5, n_shifts=None, complement=False); from the registry, opsoptics.get("high_frequency_patterns"))
Shifted high-frequency projector patterns: binary stripes with fill ratio α, a checkerboard, or phase-shifted sinusoids (one or several periods).
*shape* (H, W) is the projector frame; x is the column index.
• "stripes" — 1 where (x − s_k) mod period < α·period, for shifts s_k = floor(k·period/n_shifts); *period* an integer >= 2 and α·period must be a whole number of pixels (the realised fill is then exactly α — a rounded fill would bias the separation). Default n_shifts = period (every pixel is lit and unlit at least once). *complement* appends 1 − p for each pattern (Nayar et al. eq. 7).
• "checker" — squares of side period/2 (α = 0.5), shifted by floor(k·period/n_shifts) in both axes (n_shifts² images, default n_shifts = min(period, 5)). Not a 2-D problem, so render_transport refuses it; it is for real captures.
• "sinusoid" — 0.5 + 0.5 cos(2π x / period − 2π n / N), n = 0..N−1, N = n_shifts (default 4, >= 3) — the sign convention of fringe.wrapped_phase, which returns 2π x / period. *period* may be a sequence (a micro phase-shifting set): the stacks are concatenated in that order. *fill* must stay 0.5 here.
Returns a list of (H, W) float arrays in [0, 1] (images).
Raises ValueError: bad *shape*; unknown *kind*; *period* out of range (stripes/checker integer >= 2, checker even; sinusoid > 2); *fill* outside (0, 1) or not a whole number of pixels per period (checker and sinusoid: not 0.5); *n_shifts* out of range; *complement* with a kind other than stripes.
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_interreflection_fringe_error — py -3.11 examples/poc_interreflection_fringe_error.py
images as input)film_thickness_map · render_transport · separate_direct_global · micro_phase_decode
light_transport)groove_profile · form_factors_2d · transport_matrix_radiosity · render_transport · separate_direct_global · fringe_multipath_phase_error · predict_fringe_phase_error · micro_phase_decode
*Provenance: lighttransport.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.