I don't know how it's called in English, but sometimes some people refer to it in Brazilian Portuguese as "alto contraste", which can be translated as "high contrast". But I've searched and found it seems not to be accurate.
I made this using Corel DRAW following a tutorial I found long ago, but I lost the link to it and can't remember all the steps. I can remember it started by converting to grayscale then launching PHOTO-PAINT via a command from DRAW to complete the work.
So I ask you to please help me find the best (and easiest) way to make that effect directly in Corel PHOTO-PAINT. TIA.
1. If you want to further control your output you can explore some additional steps, for example choosing a specific RGB channel.
Image > Split Channels > RGB
And choose one of the 3 images that are already grayscale but with different combinations of gray.
2. Now, you can play with the contrast. Yes, you can change to a 1 bit image (either pure white or pure black) or you can make a really contrasted image with some few grays for antialiasing purposes.
If you choose this antialiasing option, you can use levels
Adjust > Enhance image
And play a bit with the little triangles.
Or you can play with curves.
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The final bit dept depends on the application. If it is for web display I would use the grayscale contrasted option.
I would only use a 1 bit image for a special effect printed in a commercial print system, like offset.