hx_gabor — 2D `halcon_ext` op

• Data kinds: image → image

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

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

hx_gabor: 入力 → 出力

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*

Usage

A Gabor filter (orientation theta = a*pi, frequency freq = 0.08 + 0.35b). Returns the magnitude of the response.

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

向きの規約は core の `gabor と同じ: a=0 (θ=0) が **縦縞**、a=0.5`

(θ=90°) が横縞に最も応答する。

★正規化(2026-09-02 の修正): カーネルの L1 ノルムで割る固定スケール。

以前は `_norm01`(その画像の min–max を [0,1] へ引き伸ばす)だったため、

向きによる応答の大小が潰れるどころか 順序が逆転していた —— 実測

(96×96 の横縞、b=0.5): 横縞検出器 (a=0.5) の平均 0.34663 に対し、ほとんど

反応しないはずの縦縞検出器 (a=0) が 0.58434 と高く出ていた(弱い応答ほど

引き伸ばし率が大きいため)。`|v| <= 1 なら |v * g| <= sum|g|` なので

L1 で割れば [0,1] を保ったまま向き・画像を跨いで比較できる。

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.

hx_gabor 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 `image` as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (`halcon_ext`)

hx_gen_circle · hx_gen_ellipse · hx_gen_rectangle2 · hx_gen_checker_region · hx_gen_grid_region · hx_fit_surface1 · hx_fit_surface2 · hx_cooc_feature

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

hx_gabor — 2D halcon_ext op