riesz_displacement_series — QUAT motion op

• Data kinds: video → pairs

• Call: import fullseye as fs; fs.ledger.riesz_displacement_series(video, f_lo, f_hi, fps, scales: 'int' = 4) -> 'np.ndarray' (to call the implementation directly, import quatimage; quatimage.riesz_displacement_series(video, f_lo, f_hi, fps, scales: 'int' = 4) -> 'np.ndarray'; from the registry, opsquat.get("riesz_displacement_series"))

Usage

Whole-frame displacement waveform from the monogenic phase. → (T, 2).

The contrast-weighted spatial mean of riesz_displacement: the rigid-body motion of the scene in pixels, one (dx, dy) row per frame. The (n, 2) layout is the shared 1-D convention (dsp.spectrum, funct1d, opsoptics's MTF curves), so the trace can be handed to dsp.spectrum to read off a resonant frequency without any repacking.

Weights are the |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 dividing by zero.

Accuracy, the J0 cliff and the multi-orientation failure all inherit from riesz_displacement — read its head-to-head table before trusting a number from here. On a single-grating 64x64x64 / 8 px / 4 Hz clip a true 0.5 px amplitude is recovered as 0.50000000000000 px (2.2e-16 relative); on the two-grating motionmag.synthesize_translation default the same 0.5 px comes back 13.0 % low, with nothing to signal it.

Detailed usage guide

• quaternion_monogenic family guide

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.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py

Ops the type connects to (they accept pairs as input)

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Same category (motion)

riesz_motion_magnify · riesz_displacement


*Provenance: quatimage.py — QUAT 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.