itof op• Data kinds: none → table (an op determined by its arguments alone — it takes no image or data input)
• Call: import fullseye as fs; fs.ledger.itof_noise_budget(frequency_hz=20000000.0, signal_electrons=2000.0, demod_contrast=0.5, ambient_electrons=0.0, read_noise_e=0.0, n_phases=4) (to call the implementation directly, import itof; itof.itof_noise_budget(frequency_hz=20000000.0, signal_electrons=2000.0, demod_contrast=0.5, ambient_electrons=0.0, read_noise_e=0.0, n_phases=4); from the registry, opsoptics.get("itof_noise_budget"))
Closed-form depth noise of indirect ToF (one pixel, one frequency, K equally spaced steps). Returns a table.
> The detailed description below is the original text — the summary and the headings are translated.
1 回の測定(K 段の合計)に信号 S 電子・背景光 S_bg 電子が入るとき、段ごとに A = c_d · S / K(振幅)、B = (S + S_bg) / K(オフセット)。各バケットの分散を B + σ_r² とすると、等間隔 K 段の位相の推定の標準偏差は
σ_φ = √(2 (B + σ_r²) / K) / A (4 段なら √((B + σ_r²)/2) / A)
σ_d = c / (4π f) · σ_φ
(小さい雑音の近似)。背景光は B だけを増やすので σ_d は √(S + S_bg) に比例して悪くなり、信号を k 倍にすると(背景光なしで)σ_d は 1/√k。周波数を k 倍にすると σ_d は 1/k、非曖昧距離 c/(2f) も 1/k。
返す dict: amplitude、offset、snr(A / √(B + σ_r²))、phase_sigma、depth_sigma、ambiguity_range、frequency_hz、n_phases。
Raises ValueError: 周波数が (0, 2 GHz] でない / 電子数が負・信号が 0 / demod_contrast が (0, 1] でない / n_phases が 3〜32 でない。
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_itof_multifreq — py -3.11 examples/poc_itof_multifreq.py
table as input)abcd_matrix · wavefront_stats · sfr_from_edge · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd
itof)itof_capture · itof_phase_amplitude · itof_unwrap_multifreq · itof_unwrap_error_rate · itof_multipath_separate · itof_flying_pixel_mask · itof_wiggling_correct
*Provenance: itof.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.