halcon_ext op• Data kinds: region → region
• Call: fullseye.apply(img, "hx_clip_region_rel", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: clip_region_rel (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_clip_region_rel: knob a sweep (docs site)
*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
Stages (the ops that come before → this op, left to right):
▸ hx_clip_region_rel: stages (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ hx_clip_region_rel: other inputs (docs site)
Clip a region relative to its bounding box (shave a fraction a off each side).
> The detailed description below is the original text — the summary and the headings are translated.
`v > 0.5 の region の外接矩形 [y0, y1] × [x0, x1] を求め、その高さ・幅の 0.5*a` ずつを上下左右から
削った内側の矩形に含まれる画素だけを残して 0/1 の float 配列で返す。
• `a → 各辺から削る割合 my = int((y1-y0)*0.5*a)、mx = int((x1-x0)*0.5*a)`。a=0 で無変化、a=1 で
外接矩形の中心線付近(1 行・1 列程度)しか残らない。
• `b` は未使用。
• region が空なら空のまま返す。
削るのは外接矩形に対する相対量なので、region の大きさが違っても「周辺 x% を落とす」意味が保たれる。外接矩形は
region 全体で 1 つ(成分ごとではない)ため、離れた小成分が並ぶ場合は端の成分がまるごと消えることがある。
画像基準の中央矩形で切るなら `hx_rectangle1_domain` との論理積を使う。
Border handling: treat everything outside the image as background (0) (measured; tools/impl2/border_probe.py).
• 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.
threshold 0.50 0.50 hx_clip_region_rel 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py
region as input)identity · reg_erode · reg_dilate · reg_open · reg_close · fill_holes · select_largest · remove_small
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.