tb_rgb_to_quaternion — 2D `typed` op

• Data kinds: rgbimage → qimage

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

*No figure: this op takes rgbimage as input. A Studio program starting from an image cannot reach that type — see the runnable examples below for how it is used.*

Usage

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.

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.

Runnable examples (verified samples that actually call this op)

• (none yet)

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

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

Same category (`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. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

tb_rgb_to_quaternion — 2D typed op