time op• Data kinds: volseq → volseq
• Call: import fullseye as fs; fs.ledger.volseq_magnify_motion(volseq, alpha: 'float' = 10.0, f_lo: 'float' = 0.05, f_hi: 'float' = 0.4, fps: 'float' = 1.0, sigma: 'float' = 0.5) -> 'np.ndarray' (to call the implementation directly, import live4d; live4d.volseq_magnify_motion(volseq, alpha: 'float' = 10.0, f_lo: 'float' = 0.05, f_hi: 'float' = 0.4, fps: 'float' = 1.0, sigma: 'float' = 0.5) -> 'np.ndarray'; from the registry, opslive4d.get("volseq_magnify_motion"))
Makes the small in-band motions of a volume time series alpha times larger (volseq, a 3-D version of Eulerian linear magnification).
The linear Eulerian method of Wu et al. (SIGGRAPH 2012): the layer obtained by smoothing each volume with a spatial Gaussian (sigma) is band-passed in time ([f_lo, f_hi] Hz, fps is the volume frame rate, ideal band via FFT) and alpha − 1 times it is added back to the original. Expanding the image of a translation δ, I(x − δ(t)), to 1st order, the in-band temporal change is −δ · ∇I, so the displacement of the added-back result is alpha · δ (alpha is the displacement factor: 1 is the identity, 0 removes the in-band motion). It holds only for small motions -- a rule of thumb is alpha · δ < λ / 8 (λ is the spatial wavelength after smoothing ≈ 4·sigma). Beyond that the image breaks (distortion, not amplification). Noise is amplified by the same factor (SNR does not improve).
>>> s = volseq_synth_beating((16, 24, 24), n_frames=24, period=8.0, amplitude=0.1)
>>> volseq_magnify_motion(s, alpha=8.0, f_lo=0.08, f_hi=0.2, fps=1.0).shape
(24, 16, 24, 24)
• 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.
• The canonical algorithm (author, year) and its uses are named in the family usage guide above.
• poc_live4d — py -3.11 examples/poc_live4d.py
volseq as input)volseq_mip_video · volseq_cut_video · volseq_speed · volseq_pathline_render · volseq_pathline_orbit · volseq_interpolate_flow · volseq_render_orbit · focus_sweep_height_video
time)video_interpolate_flow · volseq_interpolate_flow
*Provenance: live4d.py — LIVE4D 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.