xpil_autocontrast — 2D `gray` op

• Data kinds: image → image

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

xpil_autocontrast: 入力 → 出力

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*

Usage

Auto-contrast (clips both ends of the histogram and stretches it to the full range). Calls `PIL.ImageOps.autocontrast`.

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

a がカットオフ率（`cutoff = int(a*10)`、範囲 0〜10%。ヒストグラムの最暗・最明側からそれぞれ何 % を外れ値として無視するか）を振る。b は未使用。外れ値の影響を抑えつつコントラストを最大限に引き伸ばせる。

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.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

xpil_autocontrast 0.50 0.50

▸ Load this pipeline · Load & run

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 (`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).*

xpil_autocontrast — 2D gray op