hx_test_region_points — 2D `halcon_ext` op

• Data kinds: region → feature

• Call: fullseye.apply(img, "hx_test_region_points", 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_points (the HALCON reference is a useful guide to its meaning and parameters)

hx_test_region_points: input → output

*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_test_region_points: 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_test_region_points: stages (docs site)

Usage

The fraction of a grid of points that lies inside the region (test_region_points).

> The detailed description below is the original text — the summary and the headings are translated.

`v > 0.5 の region を step 画素おきの格子(reg[::step, ::step]`、原点は (0,0))でサンプリングし、

格子点のうち region に入っている割合を `np.float64`(0〜1)で返す。

• `a → 格子間隔 step = max(2, int((0.1 + 0.3*a) * min(h, w)))`(短辺の 10%〜40%、最小 2 画素)。

• `b` は未使用。

• 格子点が 0 個なら 0.0。

格子が細かければ region の面積率の近似になり、粗ければ「代表点がどれだけ region に落ちるか」の粗い指標になる。

格子の原点は固定なので、region を少しずらすだけで値が飛ぶ。面積率そのものが欲しいなら region の平均値を

取る方が正確。1 点の判定は `hx_test_region_point`。

Detailed usage guide

• gallery2d_halcon_ext family guide

References (sample data, literature)

• 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.

Try it in Studio

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_points 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py

Ops the type connects to (they accept `feature` as input)

identity · feature_to_img

Same category (`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).*

hx_test_region_points — 2D halcon_ext op