tb_quantize — 2D typed op

資料種類:signalsignal

呼叫:fullseye.apply(img, "tb_quantize", a=0.5, b=0.5)(2-D 的模型是一張圖 + 兩個純量旋鈕 a,b∈[0,1])

tb_quantize: input → output

*圖為在 128×128 合成輸入上實際執行的輸出。左為輸入,右為輸出。點雲以俯視散點顯示(亮度 = z),一維序列為折線,體資料為沿 z 的最大值投影,影片為中間影格,複數影像為振幅;無法成像的回傳值直接顯示數值。*

掃描旋鈕 a(0.1 / 0.5 / 0.9,另一旋鈕取預設):

tb_quantize: knob a sweep (docs site)

*旋鈕 b 不改變輸出(實測: 0.1 / 0.5 / 0.9 相同)。*

階段(前置運算子 → 本運算子,由左至右):

tb_quantize: stages (docs site)

換別的影像(合成場景 / 照片 / 硬幣。上排為輸入,下排為對應輸出。旋鈕取預設):

tb_quantize: other inputs (docs site)

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: 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.

Typed bridge of the 1d op `quantize into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives bits (default 8); b` is unused.

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。

在 Studio 中試試

下面的程式已確認可以執行(與圖相同的輸入)。在 Studio 說明中,此區塊會變成按鈕,可當場載入並執行。

img_to_signal 0.50 0.50
tb_quantize 0.50 0.50

▸ Load this pipeline  ·  Load & run

可執行的範例(實際呼叫該運算子並已驗證的樣例)

下面的範例呼叫的是底層帳本運算子 quantize。此橋接運算子只是把同一實作適配為 fn(v, a, b) 慣例,行為完全相同(只是呼叫形式不同)。

poc_cold_chain_excursionpy -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)

identity · tb_create_funct_1d_array · tb_smooth_funct_1d_gauss · tb_smooth_funct_1d_mean · tb_derivate_funct_1d · tb_integrate_funct_1d · tb_zero_crossings_funct_1d · tb_abs_funct_1d

同類別(typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample


*Provenance: ops.py — 2D 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.