region op• Data kinds: region → region
• Call: fullseye.apply(img, "remove_small", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: select_shape (the HALCON reference is a useful guide to its meaning and parameters)
*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*
Removes small connected regions based on area. Equivalent to HALCON's `select_shape` (Choose regions with the aid of shape features.).
> The detailed description below is the original text — the summary and the headings are translated.
`a が除去のしきい値（画素数）を、画像全体の画素数に対する割合 0.01〜0.16（(0.01+0.15a) * 画素数）として振る。b は未使用。しきい値以上の面積を持つ連結成分だけを残す。連結性は scipy label` の既定（4連結）。
• 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.
The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.
threshold 0.50 0.50 remove_small 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_region — py -3.11 examples/gallery2d_region.py
• quickstart — py -3.11 examples/quickstart.py
region as input)identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · invert_region
region)reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · invert_region · dist_transform
*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.