I'm not quite sure if this is what you mean but you might want to check out this site:
http://homokaasu.org/rasterbator/ Basically you get the original photo and use that site to convert it into a huge rasterized image. It converts it into a .pdf file, print them all out and you can get something like the examples on the site. If you decide to try this, please, whatever you do, cut off the white borders around each page!
I've done this twice myself and ended up with with posters about 3m by 2m, covering the entire wall.