halcon_ext op• Data kinds: image → image
• Call: fullseye.apply(img, "hx_region_to_label", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: region_to_label (the HALCON reference is a useful guide to its meaning and parameters)
*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*
Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):
▸ hx_region_to_label: knob a sweep (docs site)
*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ hx_region_to_label: other inputs (docs site)
*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*
Turn the connected components of the region thresholded at a into a label image (normalised).
> The detailed description below is the original text — the summary and the headings are translated.
`v > a を前景として ndimage.label(8 近傍)で連結成分にラベル付けし、ラベル番号 1..n を n` で割った
float 画像を返す。背景は 0、成分は `1/n, 2/n, ..., 1` の等間隔の値になる。成分が無ければ全 0。
• `a` → 二値化しきい値(region を渡すときは 0.5 にする)。
• `b` は未使用。
ラベル番号は走査順(左上から)で振られるため、同じ成分でも画像内の他の成分数 `n` が変わると値が変わる。
値で成分を識別する用途にのみ向き、値の大小に意味は無い。成分ごとの統計が欲しければ `hx_region_to_mean`
(平均 gray 値で塗る)を使う。ラベル画像から 1 成分だけを取り出すには `threshold` 系で値域を切る。
• gallery2d_halcon_ext 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.
hx_region_to_label 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
halcon_ext)hx_gen_circle · hx_gen_ellipse · hx_gen_rectangle2 · hx_gen_checker_region · hx_gen_grid_region · hx_gabor · hx_fit_surface1 · hx_fit_surface2
*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.