gray op• Data kinds: image → image
• Call: fullseye.apply(img, "equ_histo_image_rect", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
• HALCON equivalent: equ_histo_image_rect (the HALCON reference is a useful guide to its meaning and parameters)
Block-wise histogram equalization. Divides the image into `nb x nb (nb=2+4*a) blocks and performs (64-bin) histogram equalization independently within each block -- more robust against local illumination unevenness than equ_histo_image (which processes the whole image at once), but can produce step discontinuities at block boundaries (block artifacts). Equivalent to HALCON's equ_histo_image_rect` (Histogram linearization within a rectangular mask.).
> The detailed description below is the original text — the summary and the headings are translated.
`a がブロック分割数を 2〜6 の範囲で振る。b` は未使用。
• 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.