edges_color_sub_pix — 2D contour op

Data kinds: colorcontour

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

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

Usage

Extracts connected components on color edges as contours. Claimed to correspond to HALCON's `edges_color_sub_pix (extracts subpixel-accurate color edges with Deriche/Shen/Canny), but **the implementation is not subpixel-accurate** -- it thresholds the gradient magnitude from _edges_color into a binary image, connects it with 8-connectivity labeling (scipy.ndimage.label`), and returns the resulting pixel coordinates directly as contour points (all coordinates lie on the integer grid). Components with fewer than 3 pixels are discarded.

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

a はしきい値 `0.15 + 0.5 * a` を振る(大きいほど輪郭が減る)。b は

未使用。戻り値は `{"shape":..., "cs": [輪郭ごとの (N,2) 座標配列]}`。

Detailed usage guide

gallery2d_contour_measure 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)

gallery2d_contour_measurepy -3.11 examples/gallery2d_contour_measure.py

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

identity · select_contours · smooth_contours · fit_line_contours · contours_to_region · count_contours · total_length · select_contours_xld

Same category (contour)

select_contours · smooth_contours · fit_line_contours · contours_to_region · sk_find_contours · edges_sub_pix · lines_gauss · select_contours_xld


*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.