hx_sort_contours — 2D halcon_ext op

Data kinds: contourcontour

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

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

hx_sort_contours: 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):

hx_sort_contours: stages (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

hx_sort_contours: other inputs (docs site)

Usage

Sort the contours by relative position (centroid row, then column).

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

contour dict(`{"shape": (H, W), "cs": [N×2 の (row, col) 配列, ...]})の cs` を、各 contour の点の平均

(重心)の行、次に列の昇順で並べ替えて返す。点列そのものは変えない。

• `a, b` は未使用。

• dict 以外や `cs` が空なら空の contour 集合を返す(例外は出ない)。点数 0 の contour は出力から落ちる。

上→下、同じ高さなら左→右の順になるので、文字列や部品列を読み順に並べるのに使う。重心は点の単純平均で、

点の密度に偏りがあれば幾何学的な中心とずれる。`hx_union_adjacent` はリスト順に貪欲連結するため、前にこの op を

置くと連結の結果が安定する。

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
sk_find_contours 0.50 0.50
hx_sort_contours 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

gallery2d_halcon_extpy -3.11 examples/gallery2d_halcon_ext.py

Ops the type connects to (they accept contour as input)

identity · select_contours · smooth_contours · fit_line_contours · contours_to_region · count_contours · total_length · select_contours_xld

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).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.