illusion_poggendorff — GENERATIVE illusion op

• Data kinds: none → rgb (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.illusion_poggendorff(angle_deg: 'float' = 30.0, bar: 'float' = 90.0) -> 'np.ndarray' (to call the implementation directly, import illusion; illusion.illusion_poggendorff(angle_deg: 'float' = 30.0, bar: 'float' = 90.0) -> 'np.ndarray'; from the registry, opsgenerative.get("illusion_poggendorff"))

Usage

Poggendorff illusion. The oblique line is exactly 1 straight line (it is merely hidden by the band).

Invariant: the 2 line segments visible on the left and right are collinear (same slope, same intercept).

Detailed usage guide

• generative_art family guide

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.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_calipers_under_illusion — py -3.11 examples/poc_calipers_under_illusion.py

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

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Same category (illusion)

illusion_cafe_wall · illusion_muller_lyer · illusion_ponzo · illusion_zollner · illusion_fraser_spiral · illusion_ebbinghaus · illusion_kanizsa · illusion_checker_shadow


*Provenance: illusion.py — GENERATIVE 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.