Comment by geon

Funny. I referenced this exact article yesterday and implemented N-Closest.

There was a surprising amount of parameters to fiddle with. Especially since I experimented with adjusting the N depending on the distance of the matches.

I wanted to implement ordered dithering to convert images to the c64.

I think dithering looks best when there are only 2 colors involved the mix, but the palette is a bit wonky so a lot of colors are hard to represent well.

An issue I noticed was that when the top 2 candidates in a gradient flipped from A,B to B,A as the gradient moved closer to B, was that the checker pattern would get an ugly seam of double pixels, like ABABABBABABA.

I’ll experiment more with manually selecting pairs of colors that mix well and generate gradient ramps from them. Then I can pre-quantize the image and use a predetermined dither pattern for each mix. Should also allow for more artistic control.