mosaic_tiles_sites — PRINTPATH npr op

• Data kinds: image2d → pairs

• Call: import fullseye as fs; fs.ledger.mosaic_tiles_sites(image, n_tiles=400, iterations=12, seed=0, weighted=True) (to call the implementation directly, import printpath; printpath.mosaic_tiles_sites(image, n_tiles=400, iterations=12, seed=0, weighted=True); from the registry, opsprintpath.get("mosaic_tiles_sites"))

Usage

Lloyd's iteration on an image — the tile centres of a mosaic.

Places *n_tiles* sites and moves each to the centroid of the pixels it owns,

weighted by local contrast when *weighted* (so detail gets smaller tiles).

★Why this earns its place: Lloyd's iteration is a descent — the

quantisation energy cannot increase — and that is a property of the algorithm,

not of the picture. The energy is *not* reported here on purpose: the existing

`stipple_energy` measures it from the sites, so the monotonicity can be

checked by an op that did not produce them. Measuring your own descent with

your own number proves nothing.

Returns `pairs`: the site coordinates (row, col).

Raises `ValueError`: fewer than 4 tiles or more tiles than pixels;

negative iterations; a non-finite or oversized image.

Detailed usage guide

• printpath 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_beats_fringes_and_screens — py -3.11 examples/poc_beats_fringes_and_screens.py

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

stipple_energy · stroke_tour_closed · mst_length · stroke_resample_closed · stroke_tone_error · mosaic_tiles_render

Same category (npr)

halftone_screen · halftone_moire_period · engrave_lines · hatch_field · mosaic_tiles_render


*Provenance: printpath.py — PRINTPATH 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.