m1_measure_thresh — 2D measure1d op

Data kinds: imagefeature

Call: fullseye.apply(img, "m1_measure_thresh", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

HALCON equivalent: measure_thresh (the HALCON reference is a useful guide to its meaning and parameters)

Usage

Counts how many times the brightness profile crosses a specified level along a caliper line through the centre (equivalent to HALCON `measure_thresh`: extracts points with a specific gray value along a rectangle/arc).

> The detailed description below is the original text — the summary and the headings are translated.

`a は線の向き(theta = a*pi)、b` はグレー値のしきい値レベル(0〜1、そのまま)。生のプロファイル(平滑化なし)がこのレベルをまたぐ回数を feature(整数値)として返す。線が画像に掛からない場合は 0.0。

Detailed usage guide

gallery2d_contour_measure family guide

Background guides (the physics and conventions behind this op)

measurement_uncertainty — 計測の不確かさと校正の知識 — 「測れている」を主張するために

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)

gallery2d_contour_measurepy -3.11 examples/gallery2d_contour_measure.py

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

identity

Same category (measure1d)

m1_measure_projection · m1_measure_pos · m1_measure_pairs · m1_fuzzy_measure_pos


*Provenance: ops.py — 2D 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.