Here's a link to a tutorial I put up on my website some time ago.   I can't remember if it's version 2 or 3 but they're so similar that you should be able to work through any differences.  I don't do the poster edges and threshold setting method but hopefully my process will shed some light on one of the possible processes.  I now use a Wacom Tablet and Photoshop CS but Elements is more than sufficient to create the same patterns and a mouse will work as well.

 

Hope it helps!

 

Andy

 

Click HERE for the link.