deformation op• Data kinds: image → image
• Call: fullseye.apply(img, "deform_mls", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
Moving-least-squares image deformation, affine variant (Schaefer 2006).
A 5x5 grid of control points `p_i` is displaced to
`q_i = p_i + amp*[sin(2 pi gx), cos(2 pi gy)]` (gy, gx = normalised
control coordinates). For every destination pixel the weighted
least-squares affine map is re-solved with the weights
`w_i = 1/|p_i - v|^(2 alpha)`, so the warp is a *different* affine at every
pixel -- smooth, interpolating at the control points, and exact on affine
data. The backward map is obtained by solving the same MLS problem with the
roles of `p and q` swapped (the resampling formulation of the paper's
section 4), which is the exact inverse whenever the control data is affine
and a smooth approximation of it otherwise. `a` sets the amplitude
`amp = 0.12*a*min(H,W), b the falloff alpha = 0.5 + 1.5b` (large
alpha = tightly local deformation). `a = 0 gives q = p`, hence the
identity (up to sub-pixel resampling error).
• gallery2d_geometry 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_geometry — py -3.11 examples/gallery2d_geometry.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
deformation)*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.