tcspc op• Data kinds: counts → counts
• Call: import fullseye as fs; fs.ledger.tcspc_background_subtract(hist, method='median', leading_bins=None, quantile=0.5, scale=1.0) (implementation को सीधे call करना हो तो import photoncount; photoncount.tcspc_background_subtract(hist, method='median', leading_bins=None, quantile=0.5, scale=1.0), registry से लेना हो तो opsphoton.get("tcspc_background_subtract"))
arrival-time histogram से ambient-light / dark-count floor हटाता है।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
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 family guide
• Sample data catalog (DL URL / license) — 2-D के लिए skimage.data (BSD/public) + synthetic, 3-D के लिए real data sources (Stanford/PDS आदि) के DL URL।
• Operators का स्रोत और संदर्भ — इस op family के मूल research/methods के स्रोत।
• Algorithm का मानक स्रोत (लेखक, वर्ष) और उपयोग ऊपर की family usage guide में दिए गए हैं।
• photon_timeresolved — py -3.11 examples/photon_timeresolved.py
• poc_dtof_ranging — py -3.11 examples/poc_dtof_ranging.py
counts को input के रूप में लेते हैं)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. यह per-op note tools/opdocs.py md से अपने-आप generate होता है (हाथ से edit न करें)।*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.