Floyd-Steinberg dithering

These are some files from experimenting with dithering.

The purpose is both compresion as well as creating a stylistic alignment with the lo-fi color scheme that constitutes marginalia.nu's visual appearance.

The latter is accomplished through using the colors that appear in the website as a palette for the dithering algorithm. The palette is only 10 colors, which fits with ample room to spare in a 4 bit palette.

The low resolution and somewhat unique appearance is also something that makes the images appear out-of-place anywhere else; a deterrent against freebooting.

Note: Some of the sample files have a bug where white is transparent. I don't really understand what causes it, but it seems the second color in the palette is always made transparent. I've been able to work around it by adding a second white color. Some files (volvo.png and socrates.png) have been re-uploaded with the fixed algorithm.

https://encyclopedia.marginalia.nu/wiki/Floyd-Steinberg_Dithering

https://encyclopedia.marginalia.nu/wiki/Color_difference

/projects/memex.gmi