halcon_ext op• Data kinds: image → image
• Call: fullseye.apply(img, "hx_region_to_mean", 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_mean (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_mean: 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_mean: other inputs (docs site)
*No colour (H,W,3) input is shown: this op treats the colour channel as a third spatial axis (it crosses channels). Call it per channel.*
Paint each connected region with its mean grey value (image -> image). Foreground/background split at threshold a, then labelled.
> The detailed description below is the original text — the summary and the headings are translated.
`v > a を前景とし ndimage.label(4 近傍)で連結成分に分け、各成分の画素を ndimage.mean` で求めた
成分内の平均 gray 値で塗りつぶす。背景(`v <= a`)は背景画素全体の平均 1 値で塗る(背景が無ければ 0.0)。
出力は入力と同形の float 画像で、値域は入力の範囲内(正規化しない)。
• `a` → 前景/背景を分けるしきい値。a=0 なら 0 より大きい画素がすべて前景。
• `b` は未使用。
結果は成分ごとに一定値になるので、後段の `threshold` で「平均が明るい部品だけ」を選ぶような使い方ができる。
4 近傍ラベルなので斜め接触する塊は別々の平均になる。入力の検証は無い。
• 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_mean 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.