npr opimage2d → image2dimport fullseye as fs; fs.ledger.engrave_lines(image, spacing_px=6.0, angle_deg=0.0, gamma=1.0, max_width=0.95) (実装を直接呼ぶなら import printpath; printpath.engrave_lines(image, spacing_px=6.0, angle_deg=0.0, gamma=1.0, max_width=0.95)、台帳から引くなら opsprintpath.get("engrave_lines"))Copperplate engraving — parallel lines whose width carries the tone.
★Why this earns its place: while the lines do not touch, the ink coverage
of a ruling of width w and spacing d is exactly w / d. So the width
needed for a target tone is solved, not tuned: w = (1 - tone) * d. The
op therefore has a closed form to be graded against — blur the result and the
local mean must come back to the tone you asked for.
image : 2-D array in [0, 1]
spacing_px : float
Line spacing. The finest tone step a ruling can hold is 1 / spacing.
angle_deg : float
gamma : float
Tone shaping applied before solving for the width (tone**gamma).
max_width : float
Widest line as a fraction of the spacing; 1.0 would make solid black and
lose the ruling.
Returns an image2d: 1 = paper, 0 = ink.
Raises ValueError: spacing below 2 px (the ruling cannot be sampled);
max_width outside (0, 1]; non-positive gamma; a non-finite or oversized image.
py -3.11 examples/poc_beats_fringes_and_screens.pyimage2d を入力に取れる)stipple_points_from_image · stipple_energy · stroke_tone_error · halftone_screen · hatch_field · mosaic_tiles_sites · mosaic_tiles_render · print_layer_defect_map
npr)halftone_screen · halftone_moire_period · hatch_field · mosaic_tiles_sites · mosaic_tiles_render
Provenance: printpath.py — PRINTPATH operator registry. この per-op ノートは tools/opdocs.py md が自動生成(手編集しない)。
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.