deformation op• Data kinds: image → image
• Call: fullseye.apply(img, "deform_tps", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
Thin-plate-spline warp over a 5x5 control grid (Bookstein, TPAMI 1989).
The 3x3 interior control points are displaced by the deterministic smooth
field `d = amp * [sin(2 pi f gx), cos(2 pi f gy)]` (gy, gx = the control
point's normalised coordinates), the 16 border control points are pinned so
the frame stays anchored. The backward map is the TPS interpolant fitted
from the *displaced* control points back to the original ones -- the unique
minimum-bending-energy interpolant, i.e. the surface a thin metal plate
would take -- and it is evaluated at every destination pixel before bilinear
resampling. `a sets the amplitude amp = 0.15*a*min(H,W), b` the
spatial frequency `f = 0.5 + 1.5b. a = 0` leaves the control points
where they are, so the solved map is 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.