principal_comp — 2D `color` op

• Data kinds: color → color

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

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

principal_comp: 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

Performs principal component analysis (PCA) on 3 channels and reorders the color space in descending order of variance. Corresponds to HALCON's `principal_comp` (computes the principal components of a multichannel image).

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

画素を (H*W, 3) の行列とみなして平均を引き、共分散行列の固有値分解

（`np.linalg.eigh`）で固有ベクトルを求め、固有値の降順に射影する。

各成分は画像内で min-max により個別に [0,1] へ正規化するため、

出力の明るさは元画像のスケールと無関係になる（正規化後は毎回フルレンジ）。

a, b は未使用。

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

Same category (`color`)

cfa_to_rgb · trans_from_rgb · trans_to_rgb · linear_trans_color · 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).*

principal_comp — 2D color op