Error diffusion

Sierra dithering

Frankie Sierra’s three-row kernel gives smooth tone close to Jarvis–Judice–Ninke with fewer neighbours.

Good for photos.

Try Sierra on your image → Dithering algorithms compared

How it decides

         #  5  3
   2  4  5  4  2
      2  3  2         ÷ 32

Ten neighbours, two rows ahead, mild worms.

Sierra dithering applied to a photo of a lion — Slide to compare. A 0.7 mm cell on A5 with perceptual tone: 28,636 marks. Photo: Lion, Andreas Vonlanthen, 2025, Unsplash License.

Slide to compare. A 0.7 mm cell on A5 with perceptual tone: 28,636 marks. Photo: Lion, Andreas Vonlanthen, 2025, Unsplash License.

Sierra in laser software

Some laser software, such as xTool Creative Space, offers a Sierra image mode, so the texture may already look familiar. Here you can put it next to the other error diffusion kernels on the same photo before you engrave, and export a 1-bit PNG at your laser’s DPI.

Try it live

This runs in your browser. Change the algorithm, the number of cells or the threshold, or put a second algorithm next to it.

Sierra

Algorithm Compare with Cells across 96 Threshold 0.50 Serpentine scan Tone

Rendered in 0.0 ms on your machine. Every dot here is what a pen or laser would put down.

All algorithms

Every one is an option in the Dither style: dither an image online and export a 1-bit PNG for a laser or SVG dots for a plotter.