Dithering algorithms

Retro Graphics Toolkit strives to offer flexibility and choices. Dithering is no exception.

You have some choices for dithering and I plan to add even more at some point.

Floyd Steinberg
Very common error diffusion algorithm. This is the default dithering algorithm.

Riemersma
Claims to combine the advantages of ordered dithering with the advantages of error diffusion.

Nearest color
Does not do dithering of any sort, it just picks the nearest color.

Vertical dithering
Kind of like ordered dithering but only with vertical lines.

Yliluoma 1
Part of the Yliluoma series of algorithms which are described here http://bisqwit.iki.fi/story/howto/dither/jy/. Old versions of Retro Graphics Toolkit had an implementation bug that had nothing to do with Yliluoma’s code. If you are experiencing terrible quality upgrade to the latest version of Retro Graphics Toolkit.

Yliluoma 2
Another ordered dither algorithm. Note that which ordered dithering algorithm looks best will depend on the image and palette. Try them all and see what looks best, for best results.

Yliluoma 3
Good ordered dithering algorithm.

Thomas Knoll
Also a work of Yliluoma. Another ordered dithering algorithm.