trans_from_rgb — 2D `color` op

• Data kinds: color → color

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

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

trans_from_rgb: 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

Converts an RGB image to another color space (HSV / Lab / YUV / XYZ). Corresponds to HALCON's `trans_from_rgb` (conversion from RGB color space to an arbitrary color space).

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

内部は OpenCV の `cv2.cvtColor` を 8bit 経由で呼ぶだけで、変換先の

色空間そのものの定義は OpenCV の実装に従う。

a は変換先を 4 通り（HSV, Lab, YUV, XYZ の順）から選ぶ

（`min(3, int(a * 4))`）。b は未使用。8bit 量子化を経由するため、

逆変換（`trans_to_rgb`）と組み合わせても厳密には可逆でない。

Detailed usage guide

• gallery2d_color_artistic family guide

Background guides (the physics and conventions behind this op)

• 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

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.

cfa_to_rgb 0.50 0.50
trans_from_rgb 0.50 0.50

▸ Load this pipeline · Load & run

Runnable examples (verified samples that actually call this op)

• gallery2d_color_artistic — py -3.11 examples/gallery2d_color_artistic.py

Ops the type connects to (they accept `color` as input)

identity · trans_to_rgb · linear_trans_color · principal_comp · rgb1_to_gray · rgb3_to_gray · access_channel · edges_color

Same category (`color`)

cfa_to_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).*

trans_from_rgb — 2D color op