xwt_directional_detail — 2D edges op

• Data kinds: image → image

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

Usage

Directional edge detection. Selects one of the horizontal (cH), vertical (cV), or diagonal (cD) detail subbands from a single-level `db2 decomposition, normalizes its absolute value, then block-upsamples it back to the original resolution (2x2 replication via kron`) and returns it.

> The detailed description below is the original text — the summary and the headings are translated.

`b でどの方向を見るか選ぶ(min(2,int(b*3)) で cH→cV→cD の 3 択)。a` は未使用。サブバンドは元画像の半分の解像度なのでブロック状に拡大されることに注意(滑らかな拡大ではない)。

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.