estimate op• Data kinds: image2d × image2d × flow2d → flow2d
• Call: import fullseye as fs; fs.ledger.piv_deform_pass(a, b, flow, info, window=32, overlap=0.5, peak='gauss3', window_func='hann', order=3) (to call the implementation directly, import pivops; pivops.piv_deform_pass(a, b, flow, info, window=32, overlap=0.5, peak='gauss3', window_func='hann', order=3); from the registry, opspiv.get("piv_deform_pass"))
• Return value through the ledger: fullseye.ledger.piv_deform_pass(...) returns only the declared out type flow2d (the underlying function also returns auxiliary values). When you need what was dropped, use fullseye.ledger.piv_deform_pass.raw(...) or call pivops.piv_deform_pass directly.
• Underlying return: (flow, info) -> flow2d
1 pass with window deformation. Correlates only after first warping the images themselves with the predicted displacement.
Integer shifting (shift of piv_cross_correlate) assumes that the displacement is constant within the window. In fields such as rotation or shear, where the displacement varies within the window, the correlation peak collapses, so the 2 images are warped in opposite directions by half the prediction each before correlating (central-difference deformation).
Args:
a, b: image pair.
flow: predicted displacement (2, h, w) (output of piv_multipass etc.).
info: its info (the window-centre coordinates are needed).
window / overlap / peak / window_func: settings of the new pass.
order: order of the interpolation used for deformation (3 = 3rd-order spline).
Returns:
(flow (2, h', w'), info). The returned displacement is the total displacement in original image coordinates.
• piv_displacement 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.
• piv_field_analysis_tour — py -3.11 examples/piv_field_analysis_tour.py
flow2d as input)piv_outlier_mask · piv_replace_outliers · piv_vorticity · piv_divergence · piv_flow_magnitude · piv_to_velocity · piv_velocity_gradient · piv_q_criterion
estimate)piv_cross_correlate · piv_multipass · piv_ensemble_correlate
*Provenance: pivops.py — PIV 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.