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

*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).*
Demosaicing from a Bayer pattern (CFA: Color Filter Array) to an RGB image. Approximates HALCON's `cfa_to_rgb` (converts a single-chip color filter array image to an RGB image).
> The detailed description below is the original text — the summary and the headings are translated.
単一チャンネルのグレースケール画像を Bayer パターンの生データとみなし、
OpenCV の `cv2.cvtColor` でデモザイクして 3 チャンネル RGB に復元する。
image から color への橋渡し op(進化がカラー系統に入る唯一の入口)。
a は Bayer パターンの並び順を 4 通り(BG/GB/RG/GR の並び)から選ぶ
(`min(3, int(a * 4))` で 0〜3 に量子化)。b は未使用。
パターンが実際の入力と合わない場合、色ズレ・モアレが出る(本来の Bayer
配置が分からない合成画像に対してはどれも「それらしい」RGB化でしかない)。
• gallery2d_color_artistic family guide
• colorimetry — 測色と分光の知識 — 色は「分光 × 光源 × 観測者」でしか決まらない
• 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.
cfa_to_rgb 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_color_artistic — py -3.11 examples/gallery2d_color_artistic.py
color as input)identity · trans_from_rgb · trans_to_rgb · linear_trans_color · principal_comp · rgb1_to_gray · rgb3_to_gray · access_channel
color)trans_from_rgb · trans_to_rgb · linear_trans_color · principal_comp · rgb1_to_gray · rgb3_to_gray · access_channel
*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.