region op• Data kinds: region → image
• Call: fullseye.apply(img, "dist_transform", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: distance_transform (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).*
Euclidean distance transform. Equivalent to HALCON's `distance_transform` (Compute the distance transformation of a region.).
> The detailed description below is the original text — the summary and the headings are translated.
`a, b は未使用。各前景画素について最も近い背景画素までのユークリッド距離を求め（scipy.ndimage.distance_transform_edt）、_norm` でその画像内の最大値を 1 に正規化する（画像間で絶対距離の比較はできない）。骨格化・粒の中心検出等の前処理に使う。
• 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 dist_transform 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_region — py -3.11 examples/gallery2d_region.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
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.