halcon_ext op• Data kinds: image → image
• Call: fullseye.apply(img, "hx_plane_deviation", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: plane_deviation (the HALCON reference is a useful guide to its meaning and parameters)

*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).*
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ hx_plane_deviation: other inputs (docs site)
*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*
The deviation of the grey values from their first-order plane fit, |v − plane| (flatness / defect inspection).
> The detailed description below is the original text — the summary and the headings are translated.
座標を [-1,1] に正規化した基底 `[1, x, y] で gray 値を最小二乗の平面に当て(hx_fit_surface1` と同じ
回帰)、残差の絶対値 `|v - plane|` を [0,1] に clip して返す。正規化はしない(純粋な平面なら丸め誤差程度の
ほぼ 0 画像になる)。
• `a, b` は未使用。
平面からの偏差が大きい画素=照明の傾きでは説明できない構造(傷・打痕・異物)。出力は符号を捨てているので
「平面より明るい/暗い」は区別しない。区別が要るなら `hx_fit_surface1` の結果と元画像を別途引く。
1 次面なので緩やかに曲がった背景は残差に出る。その場合は `hx_fit_surface2` 側で背景を推定する。
後段は `threshold で欠陥 region 化、あるいは hx_char_threshold` の前処理として背景差し引き代わりに使える。
Blank frame (measured): feeding an image of uniform brightness gives an empty result — every pixel is background (0) — regardless of the brightness. Pure white and pure black behave alike; brightness by itself detects nothing.
• gallery2d_halcon_ext family guide
• 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.
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_plane_deviation 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_halcon_ext — py -3.11 examples/gallery2d_halcon_ext.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
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.