tcspc_background_subtract — PHOTON tcspc op

• Datenarten: counts → counts

• Aufruf: import fullseye as fs; fs.ledger.tcspc_background_subtract(hist, method='median', leading_bins=None, quantile=0.5, scale=1.0) (die Implementierung direkt: import photoncount; photoncount.tcspc_background_subtract(hist, method='median', leading_bins=None, quantile=0.5, scale=1.0); aus dem Register: opsphoton.get("tcspc_background_subtract"))

Verwendung

Entfernt den Umgebungslicht-/Dunkelzählboden aus einem Ankunftszeit-Histogramm.

> Die ausführliche Beschreibung unten ist der Originaltext — Zusammenfassung und Überschriften sind übersetzt.

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*.

Ausführlicher Anwendungsleitfaden

• Leitfaden zur Familie photon_timeresolved

Referenzen (Beispieldaten, Literatur)

• Katalog der Beispieldaten (Download-URLs / Lizenzen) — 2-D nutzt skimage.data (BSD/Public Domain) plus synthetische Bilder, 3-D nennt Download-URLs echter Datenquellen (Stanford, PDS, …).

• Herkunft und Literatur der Operatoren — die Quellen der Forschung/Verfahren, auf denen diese Operatorfamilie beruht.

• Der kanonische Algorithmus (Autor, Jahr) und seine Anwendungen stehen im Familienleitfaden oben.

Ausführbare Beispiele (verifizierte Samples, die diesen Operator wirklich aufrufen)

• photon_timeresolved — py -3.11 examples/photon_timeresolved.py

• poc_dtof_ranging — py -3.11 examples/poc_dtof_ranging.py

Typkompatible Folge-Operatoren (nehmen counts als Eingabe)

tcspc_coates_correct · tcspc_irf_convolve · tcspc_stats · dtof_depth · lifetime_fit · lifetime_phasor

Gleiche Kategorie (tcspc)

tcspc_simulate · tcspc_irf_convolve · tcspc_stats


*Provenance: photoncount.py — PHOTON Operator-Registry. Diese Notiz wird von tools/opdocs.py md erzeugt (nicht von Hand bearbeiten).*

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