algorithmFloyd–Steinberg
levels2
ink used0%
Drag across the left sheet to paint. The right panel dithers live.
Quantizer
The source sheet holds real grey values; the output panel only ever uses levels flat tones. Floyd–Steinberg pushes quantisation error to the right and below; Atkinson pushes only 3/4 of it, giving that airy early-Mac grain. E downloads the dithered panel.