I wonder can ImageMagick give you the "progressive linear blur" (or whatever you want to call it) that emulates depth of field?

Might as well ray trace it....

My comment was mostly tongue-in-cheek. mih in a sibling thread added a link to actually useful IM scripts however, one of which supports variable blur using a mask (scroll below the table and parameters for example pictures): http://www.fmwconcepts.com/imagemagick/variableblur/index.ph...