add_metrology_object_ellipse_measure — MEASURE1D model op

• Data kinds: metrologymodel → scalar

• Call: import fullseye as fs; fs.ledger.add_metrology_object_ellipse_measure(model, row, col, phi, ra, rb, n: 'int' = 40) -> 'int' (to call the implementation directly, import metrology; metrology.add_metrology_object_ellipse_measure(model, row, col, phi, ra, rb, n: 'int' = 40) -> 'int'; from the registry, opsmeasure1d.get("add_metrology_object_ellipse_measure"))

Usage

Adds an ellipse metrology object (add_metrology_object_ellipse_measure). phi = orientation of the ra axis (from the col axis, in radians).

Stacks the reference ellipse (centre (row, col) [px], radius ra in the phi direction, radius in the orthogonal direction rb) onto model["objects"] (the dict is updated in place). apply_metrology_model places points dividing the parameter angle t into n equal parts (not equal arc length, so on a flat ellipse the ends of the long axis are dense), measures edges at each point along the ellipse's outward normal ∇F, and recomputes it with an ellipse fit.

• phi: radians measured from the col axis (x) toward the row axis (image downward) (same convention as the rectangle's phi).

• ra, rb: radii [px]. Putting in 0 causes a division by 0 in the normal computation, so avoid it (not validated here).

• n: number of samples (default 40).

• Returns: index of the added position (starting at 0).

• params of the apply result is row / col / phi / ra / rb, normalised to ra >= rb (the long axis is ra), and rms is not the algebraic residual but the radial geometric residual from the centre [px].

Detailed usage guide

• subpixel_measuring 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)

• poc_dimensional_inspection — py -3.11 examples/poc_dimensional_inspection.py

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

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Same category (model)

create_metrology_model · add_metrology_object_line_measure · add_metrology_object_circle_measure · add_metrology_object_rectangle2_measure · add_metrology_object_generic


*Provenance: metrology.py — MEASURE1D 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.