entropy_image — 2D texture op

Data kinds: imageimage

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)

Usage

> This operator's description has not been translated yet. The original text follows as it is.

円形窓内のグレースケール Shannon エントロピー(``skimage.filters.rank.

entropy``、8bit 量子化)を正規化した画像。窓内の階調の「散らばり具合」を

測るテクスチャ指標で、一様な領域では低く、雑多な階調が混在する領域では

高くなる。HALCON の `entropy_image`(Calculate the entropy of gray values

within a rectangular window.)に相当(HALCON は矩形窓、ここでは円形窓を

使う近似)。

`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。

Detailed usage guide

gallery2d_texture_freq 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_texture_freqpy -3.11 examples/gallery2d_texture_freq.py

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (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.