xg_height_width_ratio — 2D `xldgeom` op

• Data kinds: contour → feature

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

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

xg_height_width_ratio: 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.*

*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*

*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):

▸ xg_height_width_ratio: stages (docs site)

Usage

Axis-aligned bounding-box height/width ratio of the point set.

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

全輪郭の点(閉輪郭の重複終点は除く)をまとめ、行方向の広がり

`h = max(row) - min(row) と列方向の広がり w = max(col) - min(col)` の比

`h / w を返す。a, b` は未使用。

返り値は `numpy.float64。点が無ければ 0.0。w < 1e-12`(全点が同じ列=

縦一直線)では `h > 1e-12` なら 1e6、そうでなければ 0.0。上限は 1e6。

軸並行の bbox なので回転に不変ではない(45° 傾いた細長い輪郭は 1 に近づく)。

回転不変な細長さは `xg_elliptic_axis / xg_eccentricity` を使う。

`h, w` は点座標の範囲(画素中心間の距離)で、画素数ベースの幅より 1 小さい。

複数輪郭があれば全体を囲む 1 つの bbox の比になる。

Detailed usage guide

• gallery2d_geometry 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
sk_find_contours 0.50 0.50
xg_height_width_ratio 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_geometry — py -3.11 examples/gallery2d_geometry.py

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

identity · feature_to_img

Same category (`xldgeom`)

xg_moments · xg_area_center · xg_eccentricity · xg_orientation · xg_elliptic_axis · xg_regress_contours · xg_clip_contours · xg_gen_polygons

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

xg_height_width_ratio — 2D xldgeom op