How do you do this to a picture?

[georges]

Just wondering what process you need to follow, what it's called and if there are any tutorials to make a picture look like this:

http://www.gunnerblog.com/images/HenryInvincible.jpg

Thanks a lot.

 

[georges]

It's close, but the one I showed is more like a cartoon with solid colours(although some colours change) and more sharp lines. Is it actually possible, or do you have to draw the image out in vectors over the top?