Hi there. I have a picture of a friend with his cat and I would like to get this effect:


Does anyone know how to do it? My further purpose is to print it on a black t-shirt.

I'd suggest that you use the Filter -> Adjust tools and do Desaturate followed by Levels (for contrast adjustment) then Threshold to give a monochrome image. You'd probably need to do manual 'touchup' in the face (white) and background (black) areas. Be careful to make adjustments so that the outlines (borders) are good because these are more difficult to manually correct than large areas of black/white.

After a few attempts you'd quickly get used to the process. (I've done this many times for various reasons but mostly to create masks.)

To make the process more flexible, you could use Filter layers on the original picture so that you don't have to keep going back to redo the entire three step process if the results are not to your liking.