region op• Data kinds: region → region
• Call: fullseye.apply(img, "boundary", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: boundary (the HALCON reference is a useful guide to its meaning and parameters)
Extracts the outer boundary line (a 1-pixel-wide ring just inside the contour) by subtracting a 1-pixel-eroded version of the region from itself. Converts a filled region into a contour line. Equivalent to HALCON's `boundary` (Reduce a region to its boundary.).
> The detailed description below is the original text — the summary and the headings are translated.
`a, b` は未使用。
• gallery2d_region 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.
• gallery2d_region — py -3.11 examples/gallery2d_region.py
• voxel_labels_color — py -3.11 examples/voxel_labels_color.py
region as input)identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small
region)reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small · invert_region
*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.