npr op• 데이터 종류: image2d → image2d
• 호출: import fullseye as fs; fs.ledger.halftone_screen(image, lpi=60.0, angle_deg=45.0, pixel_um=25.4, sharpness=8.0)(구현을 직접 호출하려면 import printpath; printpath.halftone_screen(image, lpi=60.0, angle_deg=45.0, pixel_um=25.4, sharpness=8.0), 원장에서 가져오려면 opsprintpath.get("halftone_screen"))
고전적인 회전 하프톤 스크린 —— 점의 면적이 농담을 나른다。
> 아래 상세 설명은 원문입니다 —— 요약과 제목은 번역되어 있습니다.
Thresholds the image against a rotated periodic spot function (the product of
two shifted cosines, the classical round-dot screen). *lpi* is lines per inch
and *pixel_um* the pixel pitch, so the screen frequency in pixels follows the
printing convention rather than a bare "period in pixels".
★Why this earns its place: two screens at different angles beat against
one another, and the period and direction of that moiré are a closed form
(:func:halftone_moire_period) that can be predicted *before* anything is
drawn and then measured out of the image. That is why newspaper printing puts
the plates at 15°/45°/75° — the beat is pushed to a frequency the eye does not
resolve — and this op lets that be shown as numbers, not folklore.
Parameters
----------
image : 2-D array in [0, 1]
Tone; 0 prints solid, 1 prints blank (the ink is `1 - image`).
lpi : float
Screen ruling, lines per inch. Newspapers use 65-85, magazines 133-175.
angle_deg : float
Screen angle. The classical set is K 45°, M 75°, C 15°, Y 0°.
pixel_um : float
Pixel pitch in micrometres (25.4 um = 1000 dpi).
sharpness : float
Edge hardness of the dot; large values give a hard threshold.
Returns an `image2d`: 1 = paper, 0 = ink.
Raises `ValueError`: non-positive lpi, pixel pitch or sharpness; a screen
period below 2 px (it would alias — reported, never silently drawn); a
non-finite or oversized image.
Limits: this is a *screen*, not a printer. Dot gain, ink spread and
registration error are not modelled, so measured ink is the geometric
coverage and will read lighter than a real press.
• 샘플 데이터 카탈로그(DL URL / 라이선스) —— 2-D 는 skimage.data(BSD/public)+ 합성, 3-D 는 실데이터 소스(Stanford/PDS 등)의 DL URL.
• 연산자의 내력·참고문헌 —— 이 연산자 족의 바탕이 된 연구/기법의 출처.
• 알고리즘의 정전(저자·연도)과 용도는 위의 패밀리 사용 가이드에 적혀 있습니다.
• poc_beats_fringes_and_screens — py -3.11 examples/poc_beats_fringes_and_screens.py
• poc_print_registration — py -3.11 examples/poc_print_registration.py
image2d 를 입력으로 받는 것)stipple_points_from_image · stipple_energy · stroke_tone_error · engrave_lines · hatch_field · mosaic_tiles_sites · mosaic_tiles_render · print_layer_defect_map
npr)halftone_moire_period · engrave_lines · hatch_field · mosaic_tiles_sites · mosaic_tiles_render
*Provenance: printpath.py — PRINTPATH 연산자 레지스트리. 이 op 노트는 tools/opdocs.py md 가 자동 생성합니다(직접 편집하지 마세요).*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.