When this tool is useful
Preparing a deliberate low-color print, retro graphic, e-paper preview, engraving reference, or reproducible monochrome treatment without uploading the source.
How local processing works
The browser derives bounded luminance values, quantizes them to the selected number of levels, then applies the chosen fixed threshold, Bayer matrix, or row-wise error distribution. Alpha can be retained and the output is PNG.
How to use it
- Prepare and preserve the source: Keep an unchanged source, choose one supported static image, and start with conservative settings. Preparing a deliberate low-color print, retro graphic, e-paper preview, engraving reference, or reproducible monochrome treatment without uploading the source.
- Run the bounded local operation: Process the decoded pixels in this browser; stop and adjust instead of accepting an ambiguous result. The browser derives bounded luminance values, quantizes them to the selected number of levels, then applies the chosen fixed threshold, Bayer matrix, or row-wise error distribution. Alpha can be retained and the output is PNG.
- Inspect the flattened result: Inspect gradients, faces, fine lines, transparent edges, and repeating Bayer patterns at native size, compare all methods and level counts, then test the PNG on the real display or production device before acceptance.
Important limitations
Dithering intentionally discards color and tonal precision. Floyd–Steinberg output depends on traversal direction, grayscale luminance is an approximation, transparency can reveal edge artifacts, and the preview does not simulate a specific printer, ink, display, or engraving process.
Verify the downloaded result
Inspect gradients, faces, fine lines, transparent edges, and repeating Bayer patterns at native size, compare all methods and level counts, then test the PNG on the real display or production device before acceptance.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
When is this tool useful?
Preparing a deliberate low-color print, retro graphic, e-paper preview, engraving reference, or reproducible monochrome treatment without uploading the source.
What does the local operation do?
The browser derives bounded luminance values, quantizes them to the selected number of levels, then applies the chosen fixed threshold, Bayer matrix, or row-wise error distribution. Alpha can be retained and the output is PNG.
Which limitations matter?
Dithering intentionally discards color and tonal precision. Floyd–Steinberg output depends on traversal direction, grayscale luminance is an approximation, transparency can reveal edge artifacts, and the preview does not simulate a specific printer, ink, display, or engraving process.
How should I verify the result?
Inspect gradients, faces, fine lines, transparent edges, and repeating Bayer patterns at native size, compare all methods and level counts, then test the PNG on the real display or production device before acceptance.