refocus op• Data kinds: lightfield → image2d
• Call: import fullseye as fs; fs.ledger.lf_refocus(lf, slope=0.0, *, interp='linear', edge='nearest') (to call the implementation directly, import lightfield; lightfield.lf_refocus(lf, slope=0.0, *, interp='linear', edge='nearest'); from the registry, opslightfield.get("lf_refocus"))
Shift-and-add refocus: the synthetic-aperture image focused at *slope*.
Every view (v, u) is shifted by (-s*(v - v_c), -s*(u - u_c)) — the minus undoes the parallax of a point at slope s — and the shifted views are averaged. Points at that slope add coherently and stay sharp; everything else is smeared by an amount proportional to its slope difference times the angular baseline. slope=0 is the plane the array was already focused on and returns the plain average of the views.
Ground truth it reproduces exactly (pinned in tests/test_lightfield.py):
a single-layer field synthesised at slope s0 and refocused at s0 with edge="wrap" and an integer s0 returns the original texture to 5.6e-16; sweeping the slope, the variance of the result peaks at s0 (measured exactly on the sweep grid in all 18 texture/slope combinations listed in the module docstring), and refocusing at -s0 does *not* — which is the check that catches a flipped shift sign.
Returns a (H, W) 2-D image.
Raises ValueError: *lf* not a valid light field, a non-finite or over-large *slope* (MAX_ABS_SLOPE), unknown *interp* / *edge*.
• lightfield_depth 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.
• lightfield_depth — py -3.11 examples/lightfield_depth.py
• poc_lightfield_depth — py -3.11 examples/poc_lightfield_depth.py
image2d as input)lf_from_mla · lf_disparity_to_depth · lf_all_in_focus
refocus)lf_focal_stack · lf_aperture_mask · lf_synthetic_aperture
*Provenance: lightfield.py — LIGHTFIELD 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.