halcon_ext op• Data kinds: region → feature
• Call: fullseye.apply(img, "hx_test_region_point", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: test_region_point (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.*
*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):
▸ hx_test_region_point: knob b sweep (docs site)
Stages (the ops that come before → this op, left to right):
▸ hx_test_region_point: stages (docs site)
Whether the region contains the point (normalised a = row, b = column): 1/0 (test_region_point).
Returns as a 1.0/0.0 np.float64 whether the region v > 0.5 contains the pixel at the normalised coordinates (a, b).
• a → row r = min(int(a*h), h-1) (0 is the first row, 1 the last row).
• b → column c = min(int(b*w), w-1).
Coordinates are in (row, col) order and are rounded to a pixel by truncation. Since it tests 1 pixel, it becomes unstable right at the region's border. To test around the point, first fatten the region with hx_dilation1. The containment ratio of multiple points is hx_test_region_points; the distance from a point to the region is hx_distance_pr.
• 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_test_region_point 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py
feature as input)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.