signal op• データ種: signal → signal
• 呼び出し: import fullseye as fs; fs.ledger.quantize(x, bits=8, mode='round', dither=None, seed=0) (実装を直接呼ぶなら import dsp; dsp.quantize(x, bits=8, mode='round', dither=None, seed=0)、台帳から引くなら 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.
• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。
• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。
• アルゴリズムの正典(著者・年)と用途は上記ファミリ使い方ガイドに記載。
• poc_cold_chain_excursion — py -3.11 examples/poc_cold_chain_excursion.py
signal を入力に取れる)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. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.