post op• Data kinds: image2d → image2d
• Call: import fullseye as fs; fs.ledger.dither(img, levels=2, method='ordered', matrix_size=4) (implementation को सीधे call करना हो तो import gfx2d; gfx2d.dither(img, levels=2, method='ordered', matrix_size=4), registry से लेना हो तो opsgfx2d.get("dither"))
local mean बनाए रखते हुए हर channel को levels मानों में quantise करता है।
> नीचे का विस्तृत विवरण मूल text में है — सारांश और headings का अनुवाद हो चुका है।
method:
• "ordered" — Bayer threshold matrix of side matrix_size (a power of two, 2..16). The mean error has a closed-form bound: for a uniform patch the output mean is within 0.5 / (matrix_size**2 * (levels-1)) of the input, because the fraction of thresholds crossed is the input fraction rounded to the nearest 1/matrix_size**2. At the defaults (4, 2 levels) the bound is 0.03125; the suite checks it holds for 101 grey levels x 3 matrix sizes, with zero violations.
• "floyd_steinberg" — error diffusion with the 7/3/5/1 sixteenths of Floyd & Steinberg 1976, serial and directional.
Which method preserves the mean better depends on the image, and this docstring will not pretend otherwise. Measured on a 128-step horizontal
ramp: ordered is exact (0.0) at 2, 3 and 4 levels and drifts to 1.1e-3 at 8 levels, while Floyd-Steinberg is 7.3e-4 at 2 levels and improves to 4.1e-5 at 16. Ordered wins where the level lattice divides the ramp, error diffusion wins where it does not.
Accepts (H, W) or (H, W, 3|4); an alpha channel is quantised too, because a dithered sprite with a smooth alpha is exactly the case that motivates this.
Output values lie on the lattice k / (levels - 1).
• Sample data catalog (DL URL / license) — 2-D के लिए skimage.data (BSD/public) + synthetic, 3-D के लिए real data sources (Stanford/PDS आदि) के DL URL।
• Operators का स्रोत और संदर्भ — इस op family के मूल research/methods के स्रोत।
• Algorithm का मानक स्रोत (लेखक, वर्ष) और उपयोग ऊपर की family usage guide में दिए गए हैं।
• gfx2d_scene — py -3.11 examples/gfx2d_scene.py
image2d को input के रूप में लेते हैं)shadow_cast_2d · raw_black_level · raw_dead_pixel_mask · raw_dead_pixel_correct · lens_shading_gain · lens_shading_correct · raw_apply_gains · raw_demosaic_bilinear
post)bloom · vignette · chromatic_aberration · film_grain · color_lut · color_grade · palette_quantize
*Provenance: gfx2d.py — GFX2D operator registry. यह per-op note tools/opdocs.py md से अपने-आप generate होता है (हाथ से edit न करें)।*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.