xcv2_fast_count — 2D `features` op

• Data kinds: image → feature

• Call: fullseye.apply(img, "xcv2_fast_count", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

Number of keypoints detected by the FAST corner detector (`cv2.FastFeatureDetector`).

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

`a は検出しきい値を 5〜45 に振る（threshold = int(5 + 40*a)`、大きい

ほど検出されにくくなり数が減る）。`b` は未使用。テクスチャの豊富さ・

コーナーの多さを表す特徴量で、値が大きいほど局所的な輝度変化に富む画像

であることを示す。

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_features — py -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).*

xcv2_fast_count — 2D features op