typed op• Data kinds: qimage → image
• Call: fullseye.apply(img, "tb_monogenic_phase", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*
*The output is shown in a viridis-like pseudo-colour (dark purple = low, yellow = high) so that a field of quantities — distance, phase, orientation, depth — can be read.*
*Knob a does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
*Knob b does not change the output (measured: identical at 0.1 / 0.5 / 0.9).*
Stages (the ops that come before → this op, left to right):
▸ tb_monogenic_phase: stages (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ tb_monogenic_phase: other inputs (docs site)
Local phase `atan2(|R|, f)` of a monogenic signal. → (H, W).
In `[0, pi]` — the monogenic phase is measured against the *magnitude* of
the Riesz vector, whose sign is carried by the orientation instead, so the
range is a half turn rather than a full one. That is the standard
convention (Felsberg & Sommer) and it is stated here because a caller
arriving from `complexops.cx_phase (whose raw range is (-pi, pi]`) will
otherwise assume a full turn and see a "wrapped" map that is not wrapped.
`display=True maps [0, pi] to [0, 1]` for viewing; the default is
`False — the **opposite** of cx_phase`'s default, deliberately,
because the consumers of this quantity in this module are numerical, and a
display scaling that arrives silently in a measurement is a factor of `pi`
that nothing announces.
Phase is the quantity a translation shifts linearly, which is why the whole
motion half of this module reads it. For an edge, phase 0 means the peak of
a bright line, `pi/2 a step edge and pi` the peak of a dark line — the
local *structure type*, independent of contrast.
Raises `ValueError`: the input is not a valid quaternion field, or its
`k` component is non-zero; *display* is not a bool.
Typed bridge of the quat op `monogenic_phase 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.
• 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 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.
img_to_monogenic 0.50 0.50 tb_monogenic_phase 0.50 0.50
▸ Load this pipeline · Load & run
The examples below call the underlying ledger op monogenic_phase. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).
• quaternion_monogenic — py -3.11 examples/quaternion_monogenic.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
typed)tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample
*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.