edges op• Data kinds: image → image
• Call: fullseye.apply(img, "kirsch_dir", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: kirsch_dir (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).*
Returns the index of the direction with the strongest response from the Kirsch compass filter (`argmax among the 8 directions), normalized to [0,1]. The directional component paired with kirsch_amp. Equivalent to HALCON's kirsch_dir` (Detect edges (amplitude and direction) using the Kirsch operator.).
> The detailed description below is the original text — the summary and the headings are translated.
`a, b` は未使用。方向は 8 段階の離散値しか取れない(Sobel/Prewitt の
連続角度とは分解能が異なる)。
• 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.
kirsch_dir 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.