I used to do an effect in CorelDraw that converted an image to a bitmap. The way it did it was group similar colors together into one color chunk giving it a cool effect that looked kind of like this:
However, the CorelDraw program I used is no longer supported, and I cant afford to buy a new license just for this effect. Is there another free tool that can do this (preferably on my Linux computer but I can do it on Windows too)?
Edited Note: while I understand that the information provided in this question was minimal, and more would have been ideal, I genuinely gave all the information I knew, and I am missing the vocabulary in this topic to fully explain what I was looming for. Thank you for your understanding. I did get the answers I was looking for.