texture op• Data kinds: image → image
• Call: fullseye.apply(img, "entropy_image", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: entropy_image (the HALCON reference is a useful guide to its meaning and parameters)
An image obtained by normalizing the grayscale Shannon entropy within a circular window (`skimage.filters.rank.entropy, 8-bit quantized). A texture measure of the "spread" of gray levels within the window: low in uniform regions and high in regions where diverse gray levels mix. Corresponds to HALCON's entropy_image` (Calculate the entropy of gray values within a rectangular window) -- an approximation using a circular window here versus HALCON's rectangular window.
> The detailed description below is the original text — the summary and the headings are translated.
`a が窓の半径を 1〜4 の範囲(_rad(a))で振る。b` は未使用。skimage
が無い環境ではこの分岐は呼べない。
• gallery2d_texture_freq 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.
• gallery2d_texture_freq — py -3.11 examples/gallery2d_texture_freq.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
texture)std_filter · gabor · sk_frangi · sk_meijering · sk_hessian · sk_gabor · sk_lbp · sk_entropy
*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.