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. It is the default option. ## 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 a bug with this algorithm. If you are experiencing terrible quality upgrade to the latest version of Retro Graphics Toolkit. ## Yliluoma 2 Another ordered dither algorithm. Sometimes better, sometimes worse. As with the other dithering algorithms if it looks better, use it, if it looks worse don't use it. ## Yliluoma 3 Good ordered dithering algorithm. ## Thomas Knoll Also a work of Yliluoma. Another ordered dithering algorithm.