halcon_ext op• Data kinds: region → region
• Call: fullseye.apply(img, "hx_dilation2", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: dilation2 (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_dilation2: knob a sweep (docs site)
Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):
▸ hx_dilation2: knob b sweep (docs site)
Stages (the ops that come before → this op, left to right):
▸ hx_dilation2: stages (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ hx_dilation2: other inputs (docs site)
Dilation with a reference point: after dilating, offset by the reference point (translated by b).
Takes v > 0.5 as the region, applies binary_dilation with a disc structuring element of radius r, then translates the result by sh pixels in the column direction with np.roll and returns a 0/1 float array.
• a → disc radius r = 1 + int(a*4) (1 to 5 pixels).
• b → column shift sh = int((b-0.5)*6). Values are -3 to 3, and since the fraction is truncated toward 0, for b
roughly in 1/3 to 2/3 it is 0 (no shift). Negative shifts left, positive right.
There is no row shift (it only reproduces shifting the reference point horizontally). Because of np.roll, whatever runs off one edge reappears on the opposite side (take care with regions touching the border). For plain dilation only, use hx_dilation1.
• 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_dilation2 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.