quantize — ONED signal op

• 資料種類:signal → signal

• 呼叫: import fullseye as fs; fs.ledger.quantize(x, bits=8, mode='round', dither=None, seed=0)(要直接呼叫實作,import dsp; dsp.quantize(x, bits=8, mode='round', dither=None, seed=0);從台帳取用則 ops1d.get("quantize"))

用法

給出誤差模型的純量量化器(可選抖動)。

> 以下的詳細說明為原文 —— 摘要與標題已翻譯。

*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: Delta**2/12 + (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.

參考(範例資料、文獻)

• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。

• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。

• 演算法的正典(作者、年份)與用途見上面的族使用指南。

可執行的範例(實際呼叫該運算子並已驗證的樣例)

• poc_cold_chain_excursion — py -3.11 examples/poc_cold_chain_excursion.py

型別可銜接的下一個運算子(可接受 signal 作為輸入)

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

同類別(signal)

lowpass · highpass · bandpass · envelope · rms · local_std · companding_mu_law · resample


*Provenance: dsp.py — ONED 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.