xcv_detail_enhance — 2D gray op

Data kinds: imageimage

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

xcv_detail_enhance: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):

xcv_detail_enhance: knob a sweep (docs site)

Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):

xcv_detail_enhance: knob b sweep (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

xcv_detail_enhance: other inputs (docs site)

*The 4th column is a colour (H,W,3) input. This op handles colour without crossing channels (it does not convolve the colour channel as a third spatial axis).*

Usage

OpenCV's detailEnhance (detail enhancement).

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

エッジ保存平滑化をベースに、平坦部は滑らかに保ったまま微細な

ディテール(テクスチャ)のコントラストを持ち上げる。

`a が空間範囲 sigma_s を 10〜50 で振る。b` が色差許容

`sigma_r を 0.1〜0.4 で振る。xcv_edge_preserving` と同系の

処理だが、こちらは細部を「消す」のではなく「強調する」方向のフィルタ。

Precision (measured): internally quantised to 8 bit (256 levels) — the output lands exactly on the k/255 grid. Passing float64 does not preserve that precision: a 16-bit camera's step (about 1.5e-5) is rounded to 1/255 = about 3.9e-3, and two images that differ by less than 1/255 return the same answer. Where faint intensity differences are being measured, or the output is fed on to differentiation or regression, the quantisation steps become visible — choose an op that does not pass through 8 bit.

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.

xcv_detail_enhance 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

gallery2d_gray_arithpy -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 · quantize_uniform · quantize_lloyd_max · quantization_error · dither_ordered · dither_floyd_steinberg · companding_mu_law · banding_map


*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.