halcon_ext op• Data kinds: image → image
• Call: fullseye.apply(img, "hx_shade_height_field", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: shade_height_field (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.*
*The output is shown in a viridis-like pseudo-colour (dark purple = low, yellow = high) so that a field of quantities — distance, phase, orientation, depth — can be read.*
Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):
▸ hx_shade_height_field: knob a sweep (docs site)
Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):
▸ hx_shade_height_field: knob b sweep (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ hx_shade_height_field: 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).*
Render the height field v with Lambertian shading (normal × light). The light is at azimuth a and elevation b.
> The detailed description below is the original text — the summary and the headings are translated.
`v を高さ場(gray 値 = 高さ、画素間隔 1)とみなし、np.gradient の (gy, gx)` から法線
`n = (-gx, -gy, 1) / sqrt(gx^2 + gy^2 + 1) を作り、方向 l = (cos(el)cos(az), cos(el)sin(az), sin(el))` の
平行光との内積 `n·l` を 0 で下から clip し、min-max で [0,1] に正規化して返す(Lambertian 陰影)。
• `a → 光源の方位角 az = a*2*pi(lx = cos(az) が列方向、ly = sin(az)` が行方向の成分)。
• `b → 光源の仰角 el = (0.2 + 0.7*b) * pi/2`(約 18°〜81°。1 で真上に近い)。
注意: 高さのスケール係数が無く、[0,1] の値を数百画素にわたって微分するため勾配はごく小さい。そのままでは
陰影の差がほとんど無いが、最後の min-max 正規化で見える化している。したがって出力の絶対的な明るさに意味は
無く、入力が平坦だと全画素 0 になる。深度画像や `hx_fit_surface2` で推定した背景面の凹凸を目で確かめる用途向け。
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_shade_height_field 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.