itof op• Data kinds: depth → table
• Call: import fullseye as fs; fs.ledger.itof_capture(depth, reflectivity=None, frequencies_hz=(20000000.0,), n_phases=4, signal_electrons=2000.0, demod_contrast=0.5, ambient_electrons=0.0, read_noise_e=0.0, waveform='sine', paths_depth=None, paths_amplitude=None, supersample=1, falloff_m=None, noise=True, seed=0) (to call the implementation directly, import itof; itof.itof_capture(depth, reflectivity=None, frequencies_hz=(20000000.0,), n_phases=4, signal_electrons=2000.0, demod_contrast=0.5, ambient_electrons=0.0, read_noise_e=0.0, waveform='sine', paths_depth=None, paths_amplitude=None, supersample=1, falloff_m=None, noise=True, seed=0); from the registry, opsoptics.get("itof_capture"))
Depth map → raw indirect-ToF signal (K phase-step buckets per modulation frequency, in electrons). Returns a table (dict).
> The detailed description below is the original text — the summary and the headings are translated.
画素(細かく描いた標本)ごとに、直接の経路(距離 *depth*、強さ signal_electrons · reflectivity)と、任意で余分な経路(*paths_depth* = 往復の経路長の半分 [m]、*paths_amplitude* = signal_electrons に掛ける強さ)が入る。経路 p の位相は φ_p = 4π f d_p / c。段 k(参照の位相 θ_k = 2πk/K)のバケットの期待値は
m_k = (Σ_p a_p + ambient) / K + demod_contrast · Σ_p a_p · corr(φ_p − θ_k) / K
(corr は *waveform*: "sine" なら cos、"square" なら矩形どうしの相関 = 三角波、配列なら余弦の係数 c_1..c_N)。つまり 1 回の測定(K 段の合計)に信号 a_p 電子と背景光 ambient_electrons 電子が入る。*noise* が真なら各バケットに Poisson のショット雑音と、標準偏差 *read_noise_e* の正規の読み出し雑音を足す。
*supersample* = s > 1 なら *depth* などはセンサの s 倍の細かさで描いたものとみなし、s × s の標本のバケットを平均して 1 画素にする(バケットは経路の光の線形和なので、これは画素の開口で光を足すのと同じ)。前景と背景をまたぐ画素では 2 つの位相が混ざり、フライングピクセルが生まれる。*falloff_m* を与えると直接の経路の強さに (falloff_m / depth)²(逆二乗)を掛ける。
返す dict: kind("itof_raw")、samples (F, K, H, W)、mean_samples(雑音なしの期待値)、frequencies_hz、phase_offsets_rad、true_depth(画素内の直接経路の距離の平均)、mixed(画素内の距離の幅 [m])、waveform、demod_contrast、read_noise_e、ambiguity_range (F,)。
Raises ValueError: depth が 2 次元でない・正でない・非有限 / reflectivity・経路の形が合わない・負 / 周波数が (0, 2 GHz] でない・重複 / n_phases が 3〜32 でない / demod_contrast が (0, 1] でない / 電子数が負 / 形が supersample で割り切れない / 画素数・経路数・計算量が上限を超える / waveform が不正。
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_phase_amplitude · itof_noise_budget · 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.