xsk3_is_low_contrast — 2D features op

Data kinds: imagefeature

Call: fullseye.apply(img, "xsk3_is_low_contrast", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

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

低コントラスト画像判定(skimage `exposure.is_low_contrast)。画像の輝度レンジが取りうる全レンジの fraction_threshold` 未満しか使っていないかを判定する真偽値を、0.0/1.0 の feature として返す。

`a は判定基準の割合(0.05+0.4*a で 0.05〜0.45)を振る —— 大きくするほど低コントラストと判定されやすくなる。b` は未使用。露出不足/白飛びの自動検知に使える。

Detailed usage guide

gallery2d_features 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_featurespy -3.11 examples/gallery2d_features.py

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

identity

Same category (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.