typed op• データ種: signal → signal
• 呼び出し: fullseye.apply(img, "tb_quantize", a=0.5, b=0.5) (2-D は 1 画像 + 2 スカラつまみ a,b∈[0,1] のモデル)
*図は合成の入力 128×128 で実際に走らせた出力。左が入力、右が出力。点群は上から見た散布(明るさ = z)、1-D 列は折れ線、体積は z 方向の最大値投影、動画は中央フレーム、複素画像は振幅、絵にならない返り値は値そのもの。*
つまみ a を振る(0.1 / 0.5 / 0.9、もう一方は既定):
▸ tb_quantize: knob a sweep (docs site)
*つまみ b は出力を変えない(実測: 0.1 / 0.5 / 0.9 で同一)。*
段階(前置きの op → この op。左から順):
▸ tb_quantize: stages (docs site)
別の画像でも(合成シーン / 写真 / 硬貨。上段が入力、下段がその出力。つまみは既定):
▸ tb_quantize: other inputs (docs site)
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.
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.
• 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。
下のプログラムは実際に走ることを確かめてある(図と同じ入力)。Studio のヘルプではこのブロックがボタンになり、その場で読み込んで実行できる。
img_to_signal 0.50 0.50 tb_quantize 0.50 0.50
▸ Load this pipeline · Load & run
次の例は元の台帳 op quantize を呼ぶもの。この橋渡し op は同じ実装を fn(v, a, b) 規約に合わせただけなので、挙動はそのまま当てはまる(呼び出し形だけ違う)。
• poc_cold_chain_excursion — py -3.11 examples/poc_cold_chain_excursion.py
signal を入力に取れる)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
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 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.