If you are talking about creating a vector file, I think you need Illustrator or Corel Draw and use the trace utility. Even at that, you would get spotty results since edges are not technically defined.
I created a pen effect using the Photoshop "Poster Edges" filter. At 11 x 14, these are like looking at an inked illustration. The monochrome conversion is needed first to minimize the confusion and give the filter something meaty to work with.