edges op• Data kinds: image → image
• Call: fullseye.apply(img, "sk_farid", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: edges_image (the HALCON reference is a useful guide to its meaning and parameters)
*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).*
Farid-Simoncelli gradient magnitude. Directly calls skimage's `filters.farid`. A gradient magnitude produced by an optimized 5-tap derivative kernel, said to have even smaller rotational-symmetry (directional) error than Sobel/Scharr.
> The detailed description below is the original text — the summary and the headings are translated.
HALCON の edges_image に相当(近似)。a, b は未使用。sk_scharr と同系統の「まず試すエッジ検出」だが、こちらは 5x5 相当のより大きなサポートを使う分ノイズにやや強い。
• 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.
sk_farid 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.