typed op• Data kinds: counts → counts
• Call: fullseye.apply(img, "tb_tcspc_irf_convolve", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*No figure: this op takes counts as input. A Studio program starting from an image cannot reach that type — see the runnable examples below for how it is used.*
Blur an arrival-time histogram by the instrument response (timing jitter).
The temporal analogue of a PSF convolution: a detector's timing uncertainty
(SPAD jitter + TDC quantisation + laser pulse width) smears every arrival
time by the instrument response function, here a Gaussian of full width at
half maximum *irf_fwhm_ps*. The kernel is the exact bin integral of that
Gaussian (erf differences), normalised to sum 1, truncated at
`+-truncate*sigma` and forced to odd length so the convolution is centred.
Ground truth: convolving a unit spike in the middle of a 256-bin window with
`irf_fwhm_ps = 500 at bin_ps = 50` leaves the centroid exactly
where it was (measured shift 0.0 ps — the kernel is symmetric) and gives a
profile whose measured FWHM is 501.22 ps. That 0.24% excess over 500 is the
*measurement*, not the kernel: :func:tcspc_stats finds the half-maximum
crossings by linear interpolation between bins, which slightly overestimates
the width of a Gaussian.
Total counts are preserved *except* at the window edges, where
`mode='same'` discards the tail that falls outside — measured loss exactly
0 for that centred spike, but a genuine loss for a pulse within a few sigma
of either end.
Returns a float64 1-D histogram of the same length as *hist*.
Raises `ValueError`: negative, non-finite or non-1-D *hist*, a
non-positive *bin_ps* / *irf_fwhm_ps* / *truncate*, an IRF sigma below
1e-3 bins (the kernel would be a delta and the op a no-op — say so instead
of pretending to blur), and a kernel that would be longer than the
:data:MAX_BINS cap.
Typed bridge of the photon op `tcspc_irf_convolve into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives bin_ps (default 100) and b drives irf_fwhm_ps` (default 200).
• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).
• Operator provenance and references — the sources of the research/methods this op family came from.
• (none yet)
counts as input)identity · tb_spad_deadtime_apply · tb_spad_deadtime_correct · tb_tcspc_coates_correct · tb_tcspc_background_subtract · tb_dtof_depth · tb_countrate_to_counts · tb_counts_to_countrate
typed)tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_angle_3points · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal
*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.