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])
*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).*
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.
• gallery2d_edges family guide
• 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.
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.
tf_phase_congruency 0.40 0.50
▸ Load this pipeline · Load & run
• gallery2d_edges — py -3.11 examples/gallery2d_edges.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
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).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.