tcspc op• データ種: counts → counts
• 呼び出し: import photoncount; photoncount.tcspc_background_subtract(hist, method='median', leading_bins=None, quantile=0.5, scale=1.0) (または opsphoton.get("tcspc_background_subtract"))
到達時刻ヒストグラムから環境光/暗計数の床を取り除く。
> 以下の詳細説明は原文のままです —— 要約と見出しは訳出済み。
Outdoors, most of what a dToF sensor counts is sunlight: a roughly uniform
pedestal under the return pulse. It biases the centroid toward the middle of
the window (a floor of `b` per bin pulls the first moment toward
`window/2`) and it inflates the apparent signal, so it is removed before
any depth or lifetime estimate.
The level is estimated by *method* and then subtracted (the sign trap:
the result is `hist - level, clipped at 0, never hist + level`):
• `"median"` (default) — the median of every bin. Robust while the pulse
occupies well under half the window, which is the normal dToF case.
• `"leading"` — the mean of the first *leading_bins* bins, the classical
choice when the pulse is known to arrive late (a far target).
• `"trailing"` — the mean of the last *leading_bins* bins, for
fluorescence decays where the tail is background.
• `"quantile"` — the given *quantile* of all bins, for tuning by hand.
*leading_bins* defaults to `None = min(8, len(hist))`, so the default
call works on a short histogram instead of raising over a constant nobody
chose (a fixed default of 8 made `method="leading"` fail on any histogram
with fewer than 8 bins).
*scale* multiplies the estimated level before subtraction (`scale=1.2` for
a deliberately aggressive removal). Clipping at 0 means the result is a valid
non-negative histogram that the rest of this module will accept.
Ground truth: on a noiseless histogram with a known flat pedestal of 20
counts/bin under a 5000-photon pulse covering 5.1% of the window, the median
estimate recovers 20.000000 and the returned histogram equals the pedestal-
free pulse exactly (measured area error 0.0, pinned in the tests).
Returns a float64 1-D histogram of the same length as *hist*.
Raises `ValueError`: negative, non-finite or non-1-D *hist*, an unknown
*method*, a *leading_bins* outside `[1, len(hist)]`, a *quantile* outside
`[0, 1]`, and a negative *scale*.
• photon_timeresolved ファミリ ガイド
• 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。
• photon_timeresolved — py -3.11 examples/photon_timeresolved.py
• poc_dtof_ranging — py -3.11 examples/poc_dtof_ranging.py
counts を入力に取れる)tcspc_coates_correct · tcspc_irf_convolve · tcspc_stats · dtof_depth · lifetime_fit · lifetime_phasor
tcspc)tcspc_simulate · tcspc_irf_convolve · tcspc_stats
*Provenance: photoncount.py — PHOTON 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.