tac_height_from_shading — 2D tactile op

Data kinds: imageimage

Call: fullseye.apply(img, "tac_height_from_shading", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

Usage

Height/relief map by Poisson integration of the shading gradients -- the integration stage of GelSight depth reconstruction (and of photometric stereo): the image gradients are read as surface slopes `p = gain*gx, q = gain*gy and the Poisson equation lap(h) = div(p,q) is solved spectrally, h_hat = div_hat / lap_hat with the discrete Laplacian symbol 2cos(2*pi*u/W)+2cos(2*pi*v/H)-4 and the (undetermined) DC mode pinned to zero. a = gradient gain (0.25..4.25x), b` = pre-smoothing sigma of the gradient field (0..3). Output is min-max normalised to [0,1] and refit to HxW; a constant frame integrates to a flat (all-zero) relief.

References (sample data, literature)

• 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.

Runnable examples (verified samples that actually call this op)

sim2real_and_alifepy -3.11 examples/sim2real_and_alife.py

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (tactile)

tac_contact_mask · tac_surface_normal · 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.