gray op• Data kinds: image → image
• Call: fullseye.apply(img, "gamma_image", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: gamma_image (the HALCON reference is a useful guide to its meaning and parameters)
Gamma correction `x ** (0.3 + 2.5*a). The closer a is to 0, the closer the exponent is to 0.3, lifting the shadows; the closer a is to 1, the closer the exponent is to 2.8, crushing the shadows and increasing contrast. Stands in for HALCON's gamma_image` (Perform a gamma encoding or decoding of an image.).
> The detailed description below is the original text — the summary and the headings are translated.
`a はガンマ指数を 0.3〜2.8 の範囲で振る。b` は未使用。HALCON の実装は
Encode/Decode の切替や AmpFactor など複数パラメータを持つが、ここでは
単純なべき乗写像 1 本に単純化している(近似)。
• gallery2d_gray_arith family guide
• 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.
• gallery2d_gray_arith — py -3.11 examples/gallery2d_gray_arith.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
gray)gamma · invert · scale_clip · equalize · sigmoid · clahe · sk_adapthist · sk_enhance_contrast
*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.