measure op• Data kinds: video → pairs
• Call: import motionmag; motionmag.displacement_series(video, f_lo, f_hi, fps, scales: 'int' = 4, orientations: 'int' = 4) -> 'np.ndarray' (or opsmotionmag.get("displacement_series"))
Whole-frame displacement waveform -> `(T, 2) array of (dx, dy)`.
The contrast-weighted spatial mean of :func:phase_displacement, i.e. the
rigid-body motion of the scene in pixels, one row per frame. This is the
trace to plot, or to feed to `dsp.spectrum` to read off the resonant
frequency — a vibration waveform recovered from a camera.
Weights are the same `|z|^2` contrast the field solve uses, restricted to
the pixels marked `valid`, so blank regions do not drag the average
towards zero. A clip with no valid pixel anywhere (a constant image) returns
exact zeros rather than a division by zero.
Sub-pixel accuracy and its cliff inherit from :func:phase_displacement;
measured on the 64x64x64 / 8 px / 4 Hz synthetic, a true 0.5 px amplitude is
recovered as 0.50000000 px (6.7e-16 relative), and a true 0.001 px amplitude
as 0.00100000 px (8.7e-15).
• motion_magnification family guide
• 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.
• motion_magnification — py -3.11 examples/motion_magnification.py
• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py
pairs as input)—
measure)*Provenance: motionmag.py — MOTIONMAG 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.