cv_median — 2D rank op

Data kinds: imageimage

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

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

Usage

Median filter (OpenCV implementation). A standard denoising method that replaces each pixel with the median of its square neighborhood (especially effective against salt-and-pepper noise, and relatively edge-preserving).

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

HALCON の median_image に相当。実装は `cv2.medianBlur(_u8(v), ksize=3+2*int(a*3))` —— a はカーネルサイズを 3, 5, 7, 9(奇数)に振る。b は未使用。8 bit に量子化してから処理するため、元画像の微妙な階調は失われる。sk_median_disk と違い正方形カーネル。

Detailed usage guide

gallery2d_smoothing_rank 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_smoothing_rankpy -3.11 examples/gallery2d_smoothing_rank.py

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

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

Same category (rank)

median · min_filter · max_filter · percentile · sk_median_disk · median_image · median_rect · median_separate


*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.