⬛ Image Dithering
Drag and drop an image, or click to select one
Convert an image into a black-and-white dithered image using the Floyd-Steinberg error diffusion algorithm. Useful for a retro pixel-art look, or for preparing images for black-and-white printers.
How to use
- Drag and drop an image, or click to select a file.
- Press "Apply" to see the dithered preview.
- Press "Download" to save it as a PNG.
How the calculation works
Apply dithering, which represents an image with only black and white. The density of the dots conveys the tones, so even two colours give an impression of a photograph’s shading. It uses Floyd–Steinberg error diffusion, published in 1976. 1. Convert each pixel to its brightness (luma) and make it white if bright, black if dark 2. Spread the error (the difference from the true brightness) over unprocessed neighbours in the proportions 7/16, 3/16, 5/16 and 1/16 Carrying the error forward keeps the overall appearance close to the original brightness.
Worked example
A flat 50% grey image → black and white dots in roughly equal numbers, in a checkerboard-like pattern Uses • Showing images on receipt printers or black-and-white e-paper • A retro console or newspaper-photo look
Things to be aware of
- The result is saved as PNG. JPEG would blur the edges of the dots and weaken the effect.
- Colour dithering (reducing to a fixed palette) is not supported.
- When shown scaled down, the dots merge into grey, so check it at 100% zoom.
FAQ
What is dithering?
It's an image processing technique that simulates intermediate shades using only a limited set of colors (here, just black and white), by diffusing rounding error to neighboring pixels so tones appear as a grainy pattern.
Does this support color dithering?
No, the current version only supports converting to black-and-white.
Is my uploaded image sent to a server?
No, all processing happens entirely in your browser.