Two-Row Sierra dithering online
Dither images with the Two-Row Sierra algorithm. A faster Sierra variant with smooth results. Free and private — your image never leaves the browser.
About Two-Row Sierra dithering
Two-Row Sierra is the lighter member of the Sierra family. It keeps two rows of the kernel and uses a divisor of 16, the same as Floyd–Steinberg.
It runs nearly as fast as Floyd–Steinberg while giving smoother, less directional texture.
Diffusion kernel
* 4 3 1 2 3 2 1 (÷16)
“*” marks the current pixel; numbers show how much of its quantization error each neighbour receives.
Best for
- Everyday photo dithering
- Animated frames
- Web graphics
How to dither an image
- Add your image. Click Upload image, drag a file onto the preview, or paste with Ctrl/⌘+V. JPG, PNG, WebP and GIF work.
- Pick an algorithm and palette. Error diffusion (Floyd–Steinberg, Atkinson…) for photos, Bayer for a retro crosshatch.
- Tune it. Raise pixel size for chunkier pixels; adjust brightness and contrast to control which tones become dark or light.
- Download. Export a lossless PNG at up to 8× with crisp nearest-neighbour scaling.
FAQ
What is Two-Row Sierra dithering?
Two-Row Sierra is the lighter member of the Sierra family. It keeps two rows of the kernel and uses a divisor of 16, the same as Floyd–Steinberg.
When should I use Two-Row Sierra?
Two-Row Sierra works best for: everyday photo dithering, animated frames, web graphics.
Is DitherImage free?
Yes. DitherImage is completely free with no sign-up, no watermark and no usage limits.
Are my images uploaded to a server?
No. All processing happens locally in your browser using JavaScript and the Canvas API. Your images never leave your device.