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

*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).*
A flattening filter that removes the linear trend (slope) of the whole image separately along the vertical and horizontal directions, then normalizes.
> The detailed description below is the original text — the summary and the headings are translated.
`scipy.signal.detrend を列方向・行方向の順に適用し、各行/各列の線形回帰成分を差し引く。a, b は未使用。照明ムラなど画像全体に乗った緩やかな傾斜を除去し、局所コントラストを見やすくする用途。結果は符号付きなので*0.5+0.5` で [0,1] に写像し直している。
• 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.
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.
xsp_detrend_flatten 0.50 0.50
▸ Load this pipeline · Load & run
• 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.