loop op• Data kinds: none → rgbvideo (an op determined by its arguments alone — it takes no image or data input)
• Call: import fullseye as fs; fs.ledger.perpetual_loop(kind: 'str' = 'harmonograph', frames: 'int' = 48, size: 'int' = 360, seed: 'int' = 0) -> 'np.ndarray' (to call the implementation directly, import perpetual; perpetual.perpetual_loop(kind: 'str' = 'harmonograph', frames: 'int' = 48, size: 'int' = 360, seed: 'int' = 0) -> 'np.ndarray'; from the registry, opsgenerative.get("perpetual_loop"))
Creates a seamless looping video → rgbvideo (T,H,W,3).
★The loop is not made by "returning to the start at the end". Make every time-dependent quantity a function of θ and rotate θ = 2πt/T; then t = T is the same formula as t = 0 -- that is, the seam never exists in the first place. This is not something removed by editing; it follows from the construction. perpetual_loop_seam reports that seam as a number (it comes out exactly 0).
Returns frames frames (t = 0 .. T-1). t = T coincides with t = 0, so it is not included.
• 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.
• poc_illusions_and_perpetual_drawing — py -3.11 examples/poc_illusions_and_perpetual_drawing.py
• poc_periodic_video_boundary — py -3.11 examples/poc_periodic_video_boundary.py
rgbvideo as input)loop)*Provenance: perpetual.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.