tb_rgb_to_quaternion — 2D typed op

• データ種: rgbimage → qimage

• 呼び出し: fullseye.apply(img, "tb_rgb_to_quaternion", a=0.5, b=0.5) (2-D は 1 画像 + 2 スカラつまみ a,b∈[0,1] のモデル)

使い方

Embed a colour image as pure quaternions `0 + R i + G j + B k`. → (H, W, 4).

Sangwine's 1996 encoding, and the entry point of the whole colour half of

this module: once a pixel is a quaternion, `q x conj(q)` rotates its colour

and :func:qft2 transforms the three channels as one hypercomplex signal

instead of three unrelated real ones.

The scalar (`w`) component is set to exactly zero — a *pure* quaternion —

because that is what makes the conjugation a 3-D rotation. Values are not

clamped: linear RGB after black-level subtraction legitimately goes negative,

and clipping it would change the colour direction, which is the quantity

every operator downstream reads.

Raises `ValueError: *image_rgb* is not a finite (H, W, 3)` numeric

array, is complex / bool / string-typed / masked, or exceeds

:data:MAX_PIXELS.

Typed bridge of the quat op `rgb_to_quaternion into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. This op has no tunable parameter; a and b` are unused.

参考(サンプルデータ・文献)

• サンプルデータ カタログ(DL URL / ライセンス) — 2-D は skimage.data(BSD/public)+ 合成、3-D は実データ源(Stanford/PDS 等)の DL URL。

• 演算子の来歴・参考文献 — この op 族の元になった研究/手法の出典。

実行できる例(この op を実際に呼ぶ検証済みサンプル)

• (まだありません)

型が繋がる次の op(qimage を入力に取れる)

identity · tb_quaternion_to_rgb · tb_quat_norm · tb_quat_conjugate_image · tb_quat_normalize_image · tb_monogenic_amplitude · tb_monogenic_phase · tb_monogenic_orientation

同カテゴリ(typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_angle_3points · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal

*Provenance: ops.py — 2D operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.