tb_temporal_bandpass — 2D typed op

Data kinds: videovideo

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])

tb_temporal_bandpass: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

Stages (the ops that come before → this op, left to right):

tb_temporal_bandpass: stages (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

tb_temporal_bandpass: other inputs (docs site)

Motion (GIF: frames / views / slices in turn. The still figure is the complete one; the GIF is supplementary):

tb_temporal_bandpass: animation

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.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

img_to_video 0.50 0.50
tb_temporal_bandpass 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

The examples below call the underlying ledger op temporal_bandpass. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).

motion_magnificationpy -3.11 examples/motion_magnification.py

poc_beam_modal_videopy -3.11 examples/poc_beam_modal_video.py

poc_motion_magnificationpy -3.11 examples/poc_motion_magnification.py

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_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample


*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.