cos_image — 2D `arithmetic` op

• Data kinds: image → image

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

• HALCON equivalent: cos_image (the HALCON reference is a useful guide to its meaning and parameters)

Usage

A periodic LUT based on `(cos(2*pi*x) + 1) / 2. A version phase-shifted by pi/2 relative to sin_image: it reaches its maximum (1) at x=0, its minimum (0) at x=0.5, and then rises again. Stands in for HALCON's cos_image` (Calculate the cosine of an image.).

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

`a, b は未使用。sin_image` と同じく非単調・非可逆な周期写像なので、

一般のコントラスト補正ではなく擬似的な等高線表現などに使う。

Detailed usage guide

• gallery2d_gray_arith 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_gray_arith — py -3.11 examples/gallery2d_gray_arith.py

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

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

Same category (`arithmetic`)

abs_image · sqrt_image · exp_image · log_image · sin_image · asin_image · acos_image · atan_image

*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

cos_image — 2D arithmetic op