asin_image — 2D `arithmetic` op

• Data kinds: image → image

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

• HALCON equivalent: asin_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.

`arcsin(x) / (π/2)` で [0,1] を [0,1] に写す逆正弦 LUT。x=0 近傍と x=1

近傍で傾きが急峻になり(定義域端で導関数が発散する)、中間階調を圧縮して

両端のコントラストを強調する効果を持つ。HALCON の `asin_image`

（Calculate the arcsine of an image.）の代役。

`a, b` は未使用。端点付近で数値的に敏感になる点に注意(x が 1 にごく

近いとわずかな量子化誤差でも出力が大きく動く)。

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 · cos_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).*

asin_image — 2D arithmetic op