tf_phase_congruency — 2D `edges` op

• Data kinds: image → image

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

Usage

phase_congruency: a simplified monogenic phase-congruency feature map.

Multi-scale radial log-Gabor bandpass responses (even part) plus their Riesz

(monogenic odd) components are accumulated; phase congruency is

`|sum of the (even, odd1, odd2) energy vectors| / (sum of amplitudes)`.

Because both numerator and denominator scale linearly with image gain and the

log-Gabor filters carry no DC, the result is invariant to affine illumination

change. `a is a noise threshold (fraction of mean energy); b` scales the

base wavelength. Peaks at edges/lines where the phases align.

Detailed usage guide

• gallery2d_edges family guide

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.

Runnable examples (verified samples that actually call this op)

• gallery2d_edges — py -3.11 examples/gallery2d_edges.py

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

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (`edges`)

sobel_mag · prewitt_mag · roberts_mag · dog · grad_dir · log · corner_response · sk_scharr

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

tf_phase_congruency — 2D edges op