For line art (like the zombie example) it may be possible to use one of several available semi-automated algorithms to generate a depth map. Here's a page that

For line art (like the zombie example) it may be possible to use one of several available semi-automated algorithms to generate a depth map. Here's a page that shows a few: http://parter.kaist.ac.kr/jyhahn76/project13.html http://parter.kaist.ac.kr/jyhahn76/project13.html