[francoi8]

For those wanting to explore automatically converting art pieces to 1-bit you can use 8Bit Photo Lab on iOS or Android. Select the black and white palette and choose resolution and dithering type.

Play Store: https://play.google.com/store/apps/details?id=com.ilixa.ebp&...

App Store: https://apps.apple.com/us/app/8bit-photo-lab/id6759910005

[reaperducer]

On macOS, there's a great piece of freeware called Retro Dither that does the job well: https://apps.apple.com/us/app/retro-dither-b-w-is-beautiful/...

/Not the author, just a satisfied user.

[nielsbot]

One more for iOS: BitCam

https://apps.apple.com/us/app/bitcam/id1114990619

[mark-r]

Automatic conversion to 1-bit has been available since the 1980's. The trick is to do it artfully.