signal op• Data kinds: signal → signal
• Call: import fullseye as fs; fs.ledger.quantize(x, bits=8, mode='round', dither=None, seed=0) (to call the implementation directly, import dsp; dsp.quantize(x, bits=8, mode='round', dither=None, seed=0); from the registry, ops1d.get("quantize"))
Scalar quantiser with the error model stated, plus optional dither.
*bits* sets the number of levels `L = 2**bits` over the signal's own
min..max range. *mode* is `"round" (mid-tread, unbiased) or "truncate"`
(floor, the convention PIL's posterize and most fixed-point casts use).
The two differ by more than a rounding convention. With step
`Delta = range/(L-1) both have error variance Delta**2/12`, but
truncation also carries a mean of `-Delta/2`, so its mean square error is
truncate: Delta2/12 + (Delta/2)2 = Delta**2/3
round: Delta**2/12
— a factor of 4. Anything that measures a level (not just displays it)
must round.
*dither* adds noise before quantising so the error stops being a function
of the signal: `"tpdf"` (triangular, the audio standard — two uniform draws
summed, so the error's variance no longer depends on the sample value) or
`"rpdf"` (one uniform draw). Dither raises the total error power but removes
the correlation that makes quantisation audible as distortion rather than as
hiss. `seed` fixes the draw so the op stays deterministic.
Applicability. (1) The range is taken from *this* signal, so two signals
quantised separately do not share a scale. (2) `bits=1` with no dither is a
comparator, not a quantiser — the error model does not apply. (3) The error
model assumes the signal moves by more than a step between samples; on a flat
stretch the error is a constant offset, not noise.
• 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_cold_chain_excursion — py -3.11 examples/poc_cold_chain_excursion.py
signal as input)create_funct_1d_array · create_funct_1d_pairs · smooth_funct_1d_gauss · smooth_funct_1d_mean · derivate_funct_1d · integrate_funct_1d · zero_crossings_funct_1d · local_min_max_funct_1d
signal)lowpass · highpass · bandpass · envelope · rms · local_std · companding_mu_law · resample
*Provenance: dsp.py — ONED 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.