you want to convert the image to grayscale properly (using luminance, not the mean of the rgb colors), then you can palettize it using a dithering algorithm like floyd-steinberg, with a palette containing only the colors black and white.
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I'm looking for a source code in C that does that, to include it in frei0r, before I have to go and write it myself...
I told you what to look for. It's a simple algorithm. Maybe try looking at the "implementation" section on the wikipedia page...
I would check out some tools written for the PlayDate game console (which is 1-bit)
https://devforum.play.date/t/playdither-a-web-tool-for-1-bit-image-dithering/5339
this is awesome!!!! thanks!!! <3
Looks like the arduboy's display. Might look for some C++ arduino libraries. Additionally, it never hurts to have gimp/PS skills for stuff like this, and there are likely plugins for both.
I don't understand the question. Are you looking for a tool which converts images to 1-bit? With dithering to simulate greys?
This art is super cool, btw! Where can I find more?
yes I'm looking for C algorithms for that. I just searched for "1bit old-school image"
Search for Floyd Steinberg dithering. That's the algorithm used by a lot of classic Mac software.
This web utility seems like exactly what you're describing. I think this was a small app someone made for themselves while developing a game for Playdate. The source might be available on their Github. If not they seem friendly, you could ask for it.