bridge op• Data kinds: image → rgbimage
• Call: fullseye.apply(img, "img_to_rgb", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*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.*
Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):
▸ img_to_rgb: knob a sweep (docs site)
Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):
▸ img_to_rgb: knob b sweep (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ img_to_rgb: 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).*
Give a gray image a hue and saturation, producing an (H,W,3) RGB image (sort `rgbimage`).
> The detailed description below is the original text — the summary and the headings are translated.
二色性反射モデル(拡散 = 着色、鏡面 = 白)の形で作る:
`mix = (1 - sat) + sat * chroma、chroma = HSV(hue, 1, 1)`、
`spec = clip((gray - 0.75) / 0.25, 0, 1) ** 2`、
`rgb = gray * (mix * (1 - spec) + spec)`。
つまり暗〜中間の画素は色相で着色され、**明るさ 0.75 を超える画素ほど白(無彩色)に
戻る**。彩度 0 なら 3 チャンネル同値のグレー(`spec` に依らず入力そのもの)。
どのチャンネルも入力以下なので値域は [0,1] に留まる。
• `a → 色相 hue = a`(0 で赤、1/3 で緑、2/3 で青、1 で赤に戻る)。
• `b → 彩度 sat = b`(b=0.5 で半分だけ着色)。
• 返り値: `(H, W, 3)` float64。
• 鏡面の膝 `SPECULAR_KNEE = 0.75` は固定(ノブにしていない)。
なぜ鏡面を入れるか(2026-09-07 実測): 単純な着色 `gray * mix` だと明るい部分も
同じ色相の飽和色になり、`tb_specular_coefficient_map / tb_specular_diffuse_split` /
`tb_specular_free_transform` が見る「無彩色のハイライト」が 1 画素も無く、
鏡面係数が全 0 の真っ黒な図になった。合成の入力側が族の前提(二色性)を満たす。
使いどころ: `tb_rgb_to_quaternion`(→ qimage、四元数の色 op の入口)、
`tb_specular_free_transform / tb_wetness / tb_sensor_capture`。
自然画像の色を再現するものではない(単一色相の合成)。
• gallery2d_bridge 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.
img_to_rgb 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_bridge — py -3.11 examples/gallery2d_bridge.py
rgbimage as input)identity · tb_wetness · tb_sensor_capture · tb_specular_diffuse_split · tb_specular_coefficient_map · tb_specular_free_transform · tb_rgb_to_quaternion
bridge)img_to_points · img_to_keypoints · img_to_signal · img_to_projection_profile · img_to_counts · img_to_matrix · img_to_video · img_to_volume
*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.