features op• Data kinds: image → feature
• Call: fullseye.apply(img, "xwt_detail_energy", 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).*
Energy ratio of the wavelet detail components. Decomposes with `db2` over 3 levels and returns the sum of mean squares of all detail coefficients (horizontal/vertical/diagonal at each level) divided by the total energy -- that sum plus the mean square of the approximation component. A measure of how much of the image's total energy is high-frequency (texture/noise/edges); the range is roughly [0,1).
> The detailed description below is the original text — the summary and the headings are translated.
`a, b` は未使用。値が大きいほどざらついた/エッジの多い画像、小さいほど滑らかな画像であることを示す。
• gallery2d_features 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.
xwt_detail_energy 0.50 0.50
▸ Load this pipeline · Load & run
• gallery2d_features — py -3.11 examples/gallery2d_features.py
feature as input)features)blob_count · area_frac · count_contours · total_length · vol_count · sk_euler · sk_entropy_feat · sk_blur_effect
*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.