tf_steerable_filter — 2D edges op

• Data kinds: image → image

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

Usage

steerable_filter: oriented first-derivative-of-Gaussian response.

The steerable G1 basis: the derivative of a Gaussian at orientation

`theta = a*pi is cos(theta)*Gx + sin(theta)*Gy` where Gx, Gy are the

x/y partial derivatives of the Gaussian-smoothed image. `b` sets the

Gaussian sigma. The signed response is mapped to [0,1] (0.5 = zero), so its

deviation from 0.5 peaks on edges whose gradient matches `theta`.

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).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.