hx_distance_pr — 2D `halcon_ext` op

• Data kinds: region → feature

• Call: fullseye.apply(img, "hx_distance_pr", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

• HALCON equivalent: distance_pr (the HALCON reference is a useful guide to its meaning and parameters)

hx_distance_pr: 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_distance_pr: knob a sweep (docs site)

Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):

▸ hx_distance_pr: knob b sweep (docs site)

Stages (the ops that come before → this op, left to right):

▸ hx_distance_pr: stages (docs site)

Usage

The minimum distance from the query point (normalised a, b) to the region (a feature), via the distance transform.

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

`v > 0.5 の region の補集合にユークリッド距離変換(distance_transform_edt)を掛け、正規化座標 (a, b)`

の画素での値(その画素から最も近い region 画素までの距離)を `max(H, W)` で割って 1 で頭打ちした

`np.float64` で返す。

• `a → 行 min(int(a*H), H-1)`。

• `b → 列 min(int(b*W), W-1)`。

• region が空なら 1.0(「最大距離」の意味。`hx_distance_pc` の空=0 とは逆なので注意)。

クエリ点が region の内側なら 0。距離変換は画像全体に対して計算するので 1 点の問い合わせとしては重いが、

値は厳密な画素間距離(`hx_distance_pc` のような頂点近似ではない)。含むかどうかだけなら

`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_distance_pr 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_distance_pr — 2D halcon_ext op