polygon_yaw_read — DRIVE pegsym op

• Data kinds: image2d → table

• Call: import fullseye as fs; fs.ledger.polygon_yaw_read(topview, n: 'int | None' = None, polarity: 'str' = 'dark', K: 'int' = 24, rel: 'float' = 0.02) -> 'dict' (to call the implementation directly, import pegsym; pegsym.polygon_yaw_read(topview, n: 'int | None' = None, polarity: 'str' = 'dark', K: 'int' = 24, rel: 'float' = 0.02) -> 'dict'; from the registry, opsdrive.get("polygon_yaw_read"))

Usage

Reads the orientation modulo the period 2π/n from the complex Fourier coefficients of the object contour (subpixel iso-line, the same threshold_sub_pix as pegtactile) in the top view (plane_topview, columns = +x, rows = −y). Under n-fold symmetry the only nonzero coefficients are k ≡ 1 (mod n), and arg(c₁₋ₙ c₁ⁿ⁻¹)/n does not depend on the start point (pegtactile.symmetry_order_contour). If n is given, the phase for that n is used instead of the detected n (when n is known from the drawing; the phase can be read even if edge jitter in real images makes extra coefficients significant). polarity = whether the object is dark ("dark", a hole) or bright ("bright", the peg end face). The intensities are stretched to 0..1 using the 2 % and 98 % quantiles, then the 0.5 iso-line is taken. Returns n_detected, n_used, yaw (world orientation; the sign is flipped back because image rows are −y; representative in [0, P) of period 2π/n_used), centroid_px (row, col) and amps. If n_used = 0 (circle), yaw = nan. Raises ValueError: unknown polarity, flat image, no contour, n < 0.

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_peg_symmetry_search — py -3.11 examples/poc_peg_symmetry_search.py

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

course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same

Same category (pegsym)

polygon_peg · polygon_offset · polygon_fit_check · rotation_window · polygon_two_point_depth · polygon_coverage_image · plane_topview · relative_yaw_from_images


*Provenance: pegsym.py — DRIVE 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.