tb_temporal_bandpass — 2D `typed` op

• Data kinds: video → video

• Call: fullseye.apply(img, "tb_temporal_bandpass", 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 video as input. A Studio program starting from an image cannot reach that type — see the runnable examples below for how it is used.*

Usage

Ideal temporal band-pass of every pixel's time series -> `(T, H, W)`.

Each pixel is transformed along time, every DFT bin whose frequency lies

outside `[f_lo, f_hi]` (in Hz, magnitude, DC always excluded) is zeroed,

and the result is transformed back. Frequency-selective where

`videops.moving_average and videops.spatiotemporal_gaussian` are

low-pass; this is the filter isolating "what is happening at 4 Hz".

Exact for a component sitting on a bin: with `T frames at fps`, a

sinusoid at `k*fps/T` Hz passes with gain 1 and everything else in the band

passes untouched. Measured on a bin-centred 4 Hz unit sinusoid in a 64-frame

32 fps clip that also carries a DC offset of 0.5 and a 12 Hz component of

amplitude 0.3, the recovered waveform matches the 4 Hz term alone to

`max|err| = 4.36e-15`.

A brick-wall filter rings in time; that is the price of an exact pass-band

and it is the same choice the 2012 Eulerian magnification paper makes. The

output is zero-mean along time by construction.

Typed bridge of the motionmag op `temporal_bandpass into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. This op has no tunable parameter; a and b` are unused.

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

• (none yet)

Ops the type connects to (they accept `video` as input)

identity · tb_temporal_band_power · tb_temporal_median_window · tb_moving_average_window · tb_background_subtraction_window · tb_frame_difference_causal · tb_exponential_background · tb_exponential_foreground

Same category (`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).*

tb_temporal_bandpass — 2D typed op