#filter #smart #dithering #blur #color-palette #floyd-steinberg

bin+lib undither

Smart filter to remove Floyd-Steinberg dithering from paletted images

3 stable releases

1.0.8 Nov 15, 2023
1.0.7 Jul 2, 2023
1.0.6 Jan 11, 2021
1.0.5 Jul 10, 2020
1.0.1 Nov 4, 2017

#840 in Images

GPL-3.0+

21KB
511 lines

Undo Dithering

Smart filter to remove Floyd-Steinberg dithering from paletted images. It's smarter than "smart blur", because it takes into account limitations of image palette to decide what not to blur.

The tool analyses image palette to find optimal blurring threshold. For any two adjacent pixels, if the palette has a color that is between colors of these two pixels, then it's assumed to be an edge.

The algorithm is useful when converting PNG8 to JPEG, or anim-GIF to video.

Usage

From CLI

Install Rust and then run:

cargo install undither --features=binary
undither palette-image.png truecolor-output.png

As a library

See API reference.

Examples

Dithered Undithered
Dithered Undithered
Dithered Undithered

Dependencies

~1MB
~18K SLoC