The algorithm written for the first Macintosh. Clean highlights, deep shadows and a light, airy grain that still looks good today.
Open the editor with this effect
Atkinson dithering was written by Bill Atkinson at Apple for the original Macintosh, a computer with a black and white screen and no greys at all. It is the reason early Mac photos and MacPaint art look the way they do: bright, crisp and a little contrasty, with a light sprinkle of dots instead of a heavy grain. People still reach for it because it makes a photo look drawn rather than scanned.
Like Floyd-Steinberg, Atkinson is an error diffusion method. Each pixel is rounded to black or white, and the difference between the real tone and the rounded one is pushed onto pixels that have not been processed yet.
The trick is that Atkinson only passes on three quarters of that error, split evenly across six neighbours. The last quarter is thrown away.
Losing that error is what gives it character. Light areas tend to clip to clean white, dark areas fill in to solid black, and only the midtones get dotted. The image gains contrast and loses the muddy look a full diffusion can have on a small screen.
Portraits with good light work beautifully. Skin goes clean and bright, while hair, eyes and shadows keep their shape.
Strong graphic subjects are great too: architecture, plants against the sky, objects on a plain background.
Very dark or very flat photos struggle, because detail in the deep shadows gets thrown away. Lift the brightness or contrast a little before you dither and you will keep more of it.
Open the editor from this page and Atkinson is already selected. Drop in your own photo.
Use the resolution slider to decide how big the dots are. Lower values give a chunky, retro screen look, higher values a fine print texture.
Nudge contrast and brightness until the face or subject reads clearly, then compare against Floyd-Steinberg or Bayer in the dither panel if you want a second opinion.
Add a two colour palette for an ink and paper look, then export PNG with hard pixel edges for print.
Floyd-Steinberg passes on all of the rounding error, which keeps tones accurate but can look busy. Atkinson passes on three quarters of it, so highlights and shadows go clean and the result has more contrast.
It uses the same diffusion pattern Bill Atkinson designed, applied to your photo at the resolution you choose. The look is the same family as classic Mac and HyperCard art.
Yes. Pick any palette in the editor and Atkinson dithers between those colours instead of black and white.