tactile op• Data kinds: image → image
• Call: fullseye.apply(img, "tac_surface_normal", 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).*
Surface-normal z-component (slope map) from the shading gradients, using Horn's shape-from-shading normal parameterisation `n = (-p, -q, 1)/sqrt(1+p^2+q^2) so that nz = 1/sqrt(1+p^2+q^2) with p = gain*gx, q = gain*gy. Flat (uncontacted) gel gives nz = 1, steep indentation walls tend to 0, so the map is already a valid [0,1] encoding. a = gradient gain (1..21x -- how steep the shading is taken to be), b` = pre-smoothing sigma of the image (0..3) to tame sensor noise. Constant input -> all-ones (perfectly flat gel).
• 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 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.
tac_surface_normal 0.50 0.50
▸ Load this pipeline · Load & run
• sim2real_and_alife — py -3.11 examples/sim2real_and_alife.py
image as input)identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter
tactile)tac_contact_mask · tac_height_from_shading · tac_pressure_proxy · tac_shear_field
*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.